196 results on '"Achraf Ammar"'
Search Results
152. Effects of pomegranate supplementation on exercise performance and post-exercise recovery in healthy adults: a systematic review
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Nizar Souissi, Achraf Ammar, Mouna Turki, Khaled Trabelsi, Stephen J. Bailey, Anita Hökelmann, and Hamdi Chtourou
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Adult ,Male ,0301 basic medicine ,medicine.medical_specialty ,animal structures ,Nutritional Sciences ,Medicine (miscellaneous) ,Muscle damage ,Placebo ,Sports nutrition ,Antioxidants ,Young Adult ,03 medical and health sciences ,0302 clinical medicine ,Delayed onset muscle soreness ,Heart rate ,Exercise performance ,medicine ,Humans ,Muscle Strength ,Exercise ,Randomized Controlled Trials as Topic ,Inflammation ,Lythraceae ,Cross-Over Studies ,030109 nutrition & dietetics ,Nutrition and Dietetics ,biology ,Plant Extracts ,business.industry ,C-reactive protein ,Polyphenols ,Myalgia ,030229 sport sciences ,Oxidative Stress ,Blood pressure ,Dietary Supplements ,Muscle Fatigue ,Physical therapy ,biology.protein ,Female ,Nutrition Therapy ,sense organs ,medicine.symptom ,business - Abstract
The functional significance of pomegranate (POM) supplementation on physiological responses during and following exercise is currently unclear. This systematic review aimed (i) to evaluate the existing literature assessing the effects of POM supplementation on exercise performance and recovery; exercise-induced muscle damage, oxidative stress, inflammation; and cardiovascular function in healthy adults and (ii) to outline the experimental conditions in which POM supplementation is more or less likely to benefit exercise performance and/or recovery. Multiple electronic databases were used to search for studies examining the effects of POM intake on physiological responses during and/or following exercise in healthy adult. Articles were included in the review if they investigated the effects of an acute or chronic POM supplementation on exercise performance, recovery and/or physiological responses during or following exercise. The existing evidence suggests that POM supplementation has the potential to confer antioxidant and anti-inflammatory effects during and following exercise, to improve cardiovascular responses during exercise, and to enhance endurance and strength performance and post-exercise recovery. However, the beneficial effects of POM supplementation appeared to be less likely when (i) unilateral eccentric exercise was employed, (ii) the POM administered was not rich in polyphenols (
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- 2018
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153. Addressing over-correction in adaptive card-based pull control systems
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Lorena Silva Belisario, Nesrine Azouz, Henri Pierreval, Achraf Ammar, Laboratoire d'Informatique, de Modélisation et d'Optimisation des Systèmes (LIMOS), Ecole Nationale Supérieure des Mines de St Etienne-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020]), and Ecole Nationale Supérieure des Mines de St Etienne (ENSM ST-ETIENNE)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)
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0209 industrial biotechnology ,Adaptive control ,Computer science ,Mechanical Engineering ,05 social sciences ,Control (management) ,Aerospace Engineering ,Kanban ,Control engineering ,02 engineering and technology ,Computer Science Applications ,[SPI]Engineering Sciences [physics] ,020901 industrial engineering & automation ,Control system ,0502 economics and business ,[INFO]Computer Science [cs] ,Electrical and Electronic Engineering ,Heuristics ,050203 business & management - Abstract
Adaptive card control strategy-based heuristics are used to change the number of cards dynamically in response to stochastic and fluctuated customers’ demands. However, when the decisions are taken...
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- 2018
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154. Regression Analysis of Perceived Stress among Elite Athletes from Changes in Diet, Routine and Well-Being: Effects of the COVID-19 Lockdown and 'Bubble' Training Camps
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Jad Adrian Washif, Achraf Ammar, Khaled Trabelsi, Karim Chamari, Christabelle Sheau Miin Chong, Siti Fuzyma Ayu Mohd Kassim, Philip Chun Foong Lew, Abdulaziz Farooq, David B. Pyne, and Carl James
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Male ,Health, Toxicology and Mutagenesis ,remote coaching ,emotion ,perception ,Article ,Paralympic ,detraining ,mental health ,Olympic ,quarantine ,sports nutrition ,training camp ,Humans ,Pandemics ,SARS-CoV-2 ,Public Health, Environmental and Occupational Health ,COVID-19 ,Diet ,Cross-Sectional Studies ,Athletes ,Communicable Disease Control ,Regression Analysis ,Medicine ,Stress, Psychological - Abstract
The COVID-19 pandemic has affected the lifestyles and training of elite athletes around the world. The detrimental effects of lockdown periods may vary among individuals, as well as among sports and sexes. This study investigated the changes in dietary habits, and the predictors of perceived stress during lockdown and a “bubble” training camp. This cross-sectional, online survey involved 76 elite and world-class athletes from six able-bodied sports and nine parasports, all of whom were involved in a 30-day “bubble” training camp. Questions were asked on socio-demographics, training routines and wellbeing, perceived stress, and dietary habits, pertaining to “normal” training (prelockdown), lockdown training, and “bubble” camp training periods. Changes in perceived stress were trivial to small during lockdown compared to “normal” training, and trivial to moderate during a “bubble” camp, compared to lockdown. Para-athletes, males, older athletes, less experienced athletes, married individuals, and specific ethnicities appeared to be more detrimentally affected (increased perceived stress) by lockdown. These negative experiences, however, were largely reversed during “bubble” camps. During lockdown, more athletes reported increased evening snack consumption (+8%), later meal-times (+6%), decreased fluid intake (−6%), and no breakfast (+7%). These changes were reversed during “bubble” camps (12–18% improvements). Sport classification accounted for 16% of the increased perceived stress (p = 0.001) during lockdown. Overall, socio-demographic factors, improvements in training routines, well-being, and dietary habits explained 28% of the decreased perceived stress during a “bubble” camp. In conclusion, better dietary habits, training routines and well-being have implications for reduced perceived stress. During lockdown, “bubble” camps may be beneficial, but this observation may be a case-by-case consideration, and short split “bubble” periods are recommended.
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- 2021
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155. A simulation-optimization based heuristic for the online assignment of multi-skilled workers subjected to fatigue in manufacturing systems
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Sabeur Elkosantini, Aicha Ferjani, Achraf Ammar, and Henri Pierreval
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Flexibility (engineering) ,0209 industrial biotechnology ,Engineering ,021103 operations research ,General Computer Science ,Operations research ,Heuristic ,Process (engineering) ,business.industry ,0211 other engineering and technologies ,General Engineering ,TOPSIS ,02 engineering and technology ,Task (project management) ,020901 industrial engineering & automation ,Sensitivity (control systems) ,Adaptation (computer science) ,business ,Assignment problem - Abstract
Manufacturing systems are often characterized by a stochastic and uncertain behavior in which frequent changes and unpredictable events may occur over time. Moreover, the customers’ demands can sometime evolve drastically along time. In order to cope with such changes in the manufacturing system state, and to optimize given performance criteria, the assignment of multi-skilled workers to the machines in the system can be decided online, in a dynamic manner, whenever workers become available and need to be assigned. Indeed, the starting and completion times of jobs in such systems cannot be predicted, so that static optimization approaches turn out not to be relevant. Several studies, in the ergonomics literature, have outlined that the operators' performances often decline because of their fatigue in work. In particular, in manufacturing contexts, fatigue can increase the processing times of jobs. Several online heuristic have been published, but to the best of our knowledge, they do not cope with this consequence of fatigue. We propose to solve this dynamic multi-skilled workers assignment problem using a new methodology, which aims to provide an adaptable dynamic assignment heuristic, which is used online. Our approach takes the impact of fatigue into consideration, in order to minimize the mean flowtime of jobs in the system. We suggest computing more realistic task durations, in accordance with the worker's fatigue. The heuristic uses a multi-criteria analysis, in order to find a compromise that favors short processing times and avoids congestions. The Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method is used to select the machine where to assign the worker. Since in our case no expertise is available, an offline adaptation process, based on simulation optimization, is used to identify the weights needed by TOPSIS, so as to better fit with the system specificities. A Job-Shop system is simulated to illustrate the proposed approach. The performance of the suggested heuristic is assessed and compared to two other workers assignment rules, which are widely used in the scientific literature because of their efficiency on the mean flowtime: SPT and LNQ. The comparisons are made under different conditions (staffing level, operators’ flexibility). A sensitivity analysis is also performed to analyze the impact of the way how fatigue affects the task duration. Our experimental results show that our heuristic provides better results in every case studied. Several important research directions are finally pointed out.
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- 2017
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156. Prevalence of overweight and obesity associated with the levels of physical fitness among primary school age children in Assiut city
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Anita Hökelmann, Osama Abdelkarim, Asmaa M. A. Soliman, and Achraf Ammar
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medicine.medical_specialty ,School age child ,business.industry ,Overweight and obesity ,Physical fitness ,lcsh:RJ1-570 ,Developing country ,030209 endocrinology & metabolism ,lcsh:Pediatrics ,Overweight ,Anthropometry ,medicine.disease ,Obesity ,Test (assessment) ,03 medical and health sciences ,0302 clinical medicine ,Environmental health ,medicine ,Physical therapy ,030212 general & internal medicine ,medicine.symptom ,business ,Body mass index ,Children - Abstract
Background: The prevalence of overweight and obesity has increased over the past 30 years to be doubled in children and adolescents and become a major health problem in developing countries. This phenomenon, was often attributed to the engagement in sedentary behaviors and to the lower levels of physical activity. Objectives: To evaluate the prevalence of overweight and obesity among primary school children in Assiut city, aged from 6 to 11 years and its association to the level of physical fitness. Methods: A cross-sectional study was conducted during the period 2014–2015, at 13 governmental primary schools in Assiut city. The sample consisted of 676 children (341boys and 335girls). The data were collected by measuring the anthropometric characteristics including body height, body weight and body mass index and the physical fitness items including endurance, strength, speed, coordination, and flexibility. Results: The prevalence of overweight and obesity was 11.24% and 12.28% respectively. The results of physical fitness data showed significant effects of body anthropometric characteristic in all test items except flexibility with p
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- 2017
157. COVID-19 home confinement negatively impacts social participation and life satisfaction: a worldwide multicenter study
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Achraf Ammar, Fernando Barbosa, e outros autores, and Faculdade de Psicologia e de Ciências da Educação
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- 2020
158. EEG-Based Hypo-vigilance Detection Using Convolutional Neural Network
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Siwar Chaabene, Amal Boudaya, Bassem Bouaziz, Lotfi Chaari, Anita Hökelmann, Achraf Ammar, Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université Toulouse - Jean Jaurès - UT2J (FRANCE), Université Toulouse 1 Capitole - UT1 (FRANCE), Digital Research Center of Sfax (TUNISIA), Otto Von Guericke Universität Magdeburg - OVGU (GERMANY), Institut de Recherche en Informatique de Toulouse - IRIT (Toulouse, France), Multimedia, InfoRmation systems and Advanced Computing Laboratory (MIRACL), Faculté des Sciences Economiques et de Gestion de Sfax (FSEG Sfax), Université de Sfax - University of Sfax-Université de Sfax - University of Sfax, Centre de Recherche en Numérique de Sfax (CRNS), Traitement et Compréhension d’Images (IRIT-TCI), Institut de recherche en informatique de Toulouse (IRIT), Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, Institut National Polytechnique (Toulouse) (Toulouse INP), and Otto-von-Guericke University [Magdeburg] (OVGU)
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Research areas ,Computer science ,media_common.quotation_subject ,Headset ,02 engineering and technology ,Electroencephalography ,Convolutional neural network ,Article ,[INFO.INFO-TS]Computer Science [cs]/Signal and Image Processing ,0202 electrical engineering, electronic engineering, information engineering ,medicine ,Traitement du signal et de l'image ,EEG ,media_common ,medicine.diagnostic_test ,business.industry ,Biomedical signal ,020206 networking & telecommunications ,Pattern recognition ,Eeg classification ,Hypo-vigilance detection ,020201 artificial intelligence & image processing ,Artificial intelligence ,business ,CNN ,Vigilance (psychology) - Abstract
National audience; Hypo-vigilance detection is becoming an important active research areas in the biomedical signal processing field. For this purpose, electroencephalogram (EEG) is one of the most common modalities in drowsiness and awakeness detection. In this context, we propose a new EEG classification method for detecting fatigue state. Our method makes use of a and awakeness detection. In this context, we propose a new EEG classification method for detecting fatigue state. Our method makes use of a Convolutional Neural Network (CNN) architecture. We define an experimental protocol using the Emotiv EPOC+ headset. After that, we evaluate our proposed method on a recorded and annotated dataset. The reported results demonstrate high detection accuracy (93%) and indicate that the proposed method is an efficient alternative for hypo-vigilance detection as compared with other methods.
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- 2020
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159. Prevalence of Underweight and Overweight and Its Association with Physical Fitness in Egyptian Schoolchildren
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Anita Hoekelmann, Darko Jekauc, Alexander Woll, Morteza Taheri, Nicola Luigi Bragazzi, Khaled Trabelsi, Achraf Ammar, Klaus Bös, Osama Abdelkarim, Hamdi Cthourou, and Khadijeh Irandoust
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Male ,Health, Toxicology and Mutagenesis ,Physical fitness ,BMI categories ,Overweight ,Article ,Body Mass Index ,03 medical and health sciences ,0302 clinical medicine ,Thinness ,Prevalence ,Humans ,Medicine ,Statistical analysis ,030212 general & internal medicine ,ddc:796 ,Child ,Schools ,Anthropometry ,business.industry ,Public Health, Environmental and Occupational Health ,nutritional and metabolic diseases ,schoolchildren ,030229 sport sciences ,Cross-Sectional Studies ,Athletic & outdoor sports & games ,age ,gender difference ,physical fitness ,Lower prevalence ,Egypt ,Female ,Underweight ,medicine.symptom ,business ,Demography - Abstract
Underweight and overweight are serious health concerns for many children and could be associated with low physical-fitness levels. This study aimed (i) to evaluate the prevalence of underweight and overweight and (ii) to examine its association with the physical fitness levels in primary male and female schoolchildren. Including 13 government primary-schools, a cross-sectional survey was conducted between 2014 and 2017. Anthropometric characteristics together with the physical-fitness level were measured in 931 schoolchildren aged between 6- and 11-years old. The prevalence of under- and overweight children were 8.49% and 24.06%, respectively. These proportions were not significantly different between males and females and were affected by age (p <, 0.001), with a higher prevalence of overweight and a lower prevalence of underweight at 9&ndash, 11 years, compared to 6&ndash, 8 years old. Concerning the physical fitness levels, statistical analysis showed a better performance among males compared to females, among participants aged 9&ndash, 8 years old, and among underweight and normal-weight, compared to overweight children (p <, 0.001). There was a higher prevalence of overweight and lower prevalence of underweight at 9&ndash, 11 years compared to 6&ndash, 8 years old. Physical fitness levels were better in (i) males, compared to females, (ii) schoolchildren aged 9&ndash, 8 years old, and (iii) underweight and normal-weight, compared to overweight children.
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- 2020
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160. Effects of COVID-19 home confinement on eating behaviour and physical activity: results of the ECLB-COVID19 International Online Survey
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Achraf Ammar, Fernando Barbosa, Fernando Ferreira-Santos, e outros autores, and Faculdade de Psicologia e de Ciências da Educação
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- 2020
161. Effects of Polyphenol-Rich Interventions on Cognition and Brain Health in Healthy Young and Middle-Aged Adults: Systematic Review and Meta-Analysis
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Achraf, Ammar, Khaled, Trabelsi, Omar, Boukhris, Bassem, Bouaziz, Patrick, Müller, Jordan, M Glenn, Nicholas T, Bott, Notger, Müller, Hamdi, Chtourou, Tarak, Driss, and Anita, Hökelmann
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cognition ,meta-analysis ,brain ,neuroplasticity ,lcsh:R ,lcsh:Medicine ,Review ,ddc:610 ,polyphenols - Abstract
Context: Affecting older and even some younger adults, neurodegenerative disease represents a global public health concern and has been identified as a research priority. To date, most anti-aging interventions have examined older adults, but little is known about the effects of polyphenol interventions on brain-related aging processes in healthy young and middle-aged adults. Objective: This systematic review and meta-analysis aimed to evaluate the acute and chronic effects of (poly)phenol-rich diet supplementation on cognitive function and brain health in young and middle-aged adults. In July 2019, two electronic databases (PubMed and Web of Science) were used to search for relevant trials examining the effect of acute or chronic (poly)phenol-rich supplementation on cognitive function and neuroprotective measures in young and middle-aged adults (p = 0.033), which was accompanied by higher performance in serial (7s) subtraction (ES = 1.467, p = 0.001) and decreases in simple reaction time (ES = −0.926, p = 0.015) and mental fatigue (ES = −3.521 p = 0.010). Data related to cognitive function were skewed towards an effect from acute compared to chronic polyphenol intervention; data related to BDNF were skewed toward an effect from higher bioavailability phenolic components. Conclusion: This meta-analysis provides promising findings regarding the usefulness of polyphenol-rich intervention as an inexpensive approach for enhancing circulation of pro-cognitive neurotrophic factors. These beneficial effects appear to depend on the supplementation protocols. An early acute and/or chronic application of low- to high-dose phenolic components with high bioavailability rates (≥30%) at a younger age appear to provide more promising effects.
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- 2020
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162. The Effect of Aquatic Exercise on Postural Mobility of Healthy Older Adults with Endomorphic Somatotype
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Khaled Trabelsi, Cyrine H'mida, Khadijeh Irandoust, Hamdi Chtourou, Morteza Taheri, Achraf Ammar, Pantelis T. Nikolaidis, Thomas Rosemann, Beat Knechtle, Masoud Mirmoezzi, and University of Zurich
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Male ,Risk ,11035 Institute of General Practice ,medicine.medical_specialty ,Health Status ,Health, Toxicology and Mutagenesis ,fall ,lcsh:Medicine ,610 Medicine & health ,Fear of falling ,Article ,03 medical and health sciences ,0302 clinical medicine ,Physical medicine and rehabilitation ,Statistical significance ,water exercise ,2307 Health, Toxicology and Mutagenesis ,medicine ,Humans ,Exercise ,Gait ,Postural Balance ,postural mobility ,Aged ,Balance (ability) ,Somatotypes ,business.industry ,Tinetti test ,lcsh:R ,Public Health, Environmental and Occupational Health ,Aquatic exercise ,Water ,Motor control ,030229 sport sciences ,endomorph ,2739 Public Health, Environmental and Occupational Health ,Middle Aged ,Aquatic environment ,Female ,medicine.symptom ,business ,030217 neurology & neurosurgery - Abstract
The fear of falling (FOF) limits the movements of the older adults, which, in turn, might impair postural mobility. An aquatic environment has a relatively low risk of falling and can improve motor abilities. The aim of this study was to investigate the effect of aquatic exercise on postural mobility of the healthy endomorph elderly somatotype. Therefore, 37 healthy endomorphic older adults with an average age of 64.38 ±, 4.12 years participated in this study. Participants were randomly divided into four groups (i.e., Aquatic exercise, Dry-land exercise, Aquatic control, and Dry-land control). The Heath-Carter method was used to estimate the criterion somatotype, and the Tinetti method was used to determine postural mobility. Covariance analysis was used to examine the mean differences at a significance level of p <, 0.05. The results showed that there was a significant difference between the aquatic exercise group and the two control groups (p <, 0.01), and the dry-land exercise group was significantly different from the aquatic control (p <, 0.05) and dry-land control groups (p <, 0.01). The results indicate that the design of aquatic exercise programs, especially for endomorphic older adults with inappropriate body shape, for whom dry-land exercises are not appropriate, likely, has a positive effect on the motor control and both the balance and gait and provide appropriate postural mobility without FOF in older adults.
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- 2019
163. Practical recommendations to improve sleep during Ramadan observance in healthy practitioners of physical activity
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Khaled, Trabelsi, Achraf, Ammar, Sahar, Zlitni, Omar, Boukhris, Aimen, Khacharem, Kais, El-Abed, Saber, Khanfir, Roy J, Shephard, Stephen R, Stannard, Nicola L, Bragazzi, and Hamdi, Chtourou
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Humans ,Fasting ,Sleep ,Exercise ,Islam ,Sports - Abstract
During the month of Ramadan, many Muslims continue to exercise and/or to compete in sporting events. However, the combination of Ramadan observance (RO) and physical activity (PA) is likely to be associated with disrupted sleep-wake patterns.to (i) evaluate the effects of RO on sleep patterns in practitioners of PA and (ii) provide some evidence-based practical recommendations to improve an active individual's sleep patterns during RO.The entire content of two databases, PubMed/MEDLINE and Web of Science was searched for relevant articles through March, 25 2019. All accepted articles concerned healthy practitioners of PA and have assessed sleep quantity and/or quality and/or daily naps, whether based on objective or subjective methods.Thirteen studies evaluated total sleep time (TST) of active individuals in relation to RO; TST decreased in five studies, increased in one and remained unchanged in seven studies. Sleep quality was self-estimated in five studies, with three noting a decreased quality of sleep and two reporting no change. The duration of daily naps was increased in two studies. Conclusions and practical recommendations: Continuation of PA during RO did not decrease TST. However, no firm conclusions can be drawn regarding sleep quality/characteristic and daily naps durations. Sleep quantity and quality should be evaluated in order to counteract sleep disturbances. Physically active individuals should avoid large late night meal, and if possible take 20- to 30- minute daytime naps. A 10- minute shower at ∼40°C and a self-administered 6-min mindfulness induction video may be helpful immediately before bedtime. Tryptophan (1g/day) or melatonin (5- 8mg) supplements may also improve sleep characteristics.
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- 2019
164. Effects of Ramadan fasting on athletes' hematological indices: a systematic review
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Khaled, Trabelsi, Roy J, Shephard, Omar, Boukhris, Achraf, Ammar, Kais, El-Abed, Saber, Khanfir, Ahmed, Hakim, and Nicola L, Bragazzi
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Hemoglobins ,Hematologic Tests ,Hematocrit ,Athletes ,Platelet Count ,Humans ,Fasting ,Islam - Abstract
To evaluate the effects of Ramadan fasting on hematological data in athletes through a systematic appraisal of the literature.Systematic review Data sources: The entire content of two databases, PubMed/MEDLINE and Web of Science Eligibility criteria for selecting studies: Ramadanrelated measurements of any hematological indices in athletes were considered. Both single-group pre-post with and without a control group studies conducted in athletes and published in English language before December 31, 2018 were included. Study appraisal: The methodological quality of the studies identified was assessed using 'QualSyst'.Of nine selected articles, eight were of moderate quality and only one was of strong quality. The main problem to date has been a lack of appropriate controls. Compared to before Ramadan, hematocrit and hemoglobin values increased in three studies, decreased in one study and did not change in one study during Ramadan fasting. Another study reported increased hematocrit and a puzzling decrease of hemoglobin during as compared to before Ramadan fasting. In most studies, blood platelet counts and the limited number of immune function used to date remainedunchanged.All reported changes in hematological indices remained within the normal reference range of the laboratory. Therefore, regular training can continue safely during Ramadan fasting from a hematological view point.
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- 2019
165. Nap Opportunity As a Strategy to Improve Short-Term Repetitive Maximal Performance During the 5-m Shuttle Run Test: A Brief Review
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Achraf Ammar, Hamdi Chtourou, Nizar Souissi, Cyrine H'mida, Omar Boukhris, and Khaled Trabelsi
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medicine.medical_specialty ,Sleep quality ,Cognition ,030229 sport sciences ,Nap ,03 medical and health sciences ,0302 clinical medicine ,Physical medicine and rehabilitation ,Time of day ,Physical performance ,mental disorders ,medicine ,Psychology ,psychological phenomena and processes ,030217 neurology & neurosurgery ,Shuttle run test - Abstract
Sleep is fundamental for recovery and good mental, cognitive and physical performance. Many factors could affect the sleep of the physical active people or athletes such as: late night training sessions or competition, Ramadan fasting and jetlag. These conditions that affect the sleep quality have significant negative effects on mental, cognitive and physical performance. Thus, scientists have to find strategies to overcome the perturbation of sleep and to optimize mental, cognitive and physical performance especially for physical active people and athletes. One of the proposed strategies is the nap opportunity. Otherwise, in their routinely training sessions, athletes are required to perform short-term repetitive maximal sprints. One of the utilized exercise for testing or training is the 5-m shuttle run test (5mSRT). Recent studies concluded that a nap opportunity has a positive effect on performance during the 5mSRT. These studies reported that this positive effect depends on the duration and the time of day of the nap opportunity. Indeed, the positive effect of the nap opportunity was better after a duration of 45-minutes compared to a 25-minutes. Also, this positive effect was reported when the nap opportunity was performed at 14h00 or 15h00. However, no-positive effect was reported when the nap opportunity was realized at 13h00.
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- 2019
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166. Dental Trauma First-Aid Knowledge and Attitudes of Physical Education Teachers: A Systematic Review and Meta-Analysis of the Literature with Meta-Regressions
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Omar Boukhris, Hamdi Chtourou, Achraf Ammar, Sahar Zlitni, Roy J. Shephard, Khaled Trabelsi, Aïmen Khacharem, Nicola Luigi Bragazzi, and Saber Khanfir
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knowledge ,Public Administration ,media_common.quotation_subject ,Physical Therapy, Sports Therapy and Rehabilitation ,physical education teachers ,meta-regressions ,systematic review and meta-analysis ,Physical education ,03 medical and health sciences ,0302 clinical medicine ,Developmental and Educational Psychology ,Computer Science (miscellaneous) ,medicine ,Quality (business) ,Lack of knowledge ,media_common ,Medical education ,education ,Dental trauma ,attitudes ,Knowledge level ,Avulsed Tooth ,030229 sport sciences ,030206 dentistry ,medicine.disease ,dental injuries ,Computer Science Applications ,Meta-analysis ,Psychology ,lcsh:L ,First aid ,lcsh:Education - Abstract
The main objective of the present review is to evaluate the knowledge and attitudes of physical education (PE) teachers concerning dental trauma first-aid through a systematic appraisal of the literature, meta-analysis and meta-regressions. The entire content of PubMed and ISI/Web of Science was mined. Eligibility criteria for selecting studies were studies evaluating dental trauma first-aid knowledge and/or attitudes and/or the effectiveness of mouthguards use by PE teachers. Articles written in any language and published or accepted by peer-reviewed journals were considered. Methodological quality was assessed using an adapted version of the Downs and Black instrument. Of 15 selected articles, three were of strong quality, three were moderate, and the remaining nine were rated as weak. The majority of studies showed that PE teachers had an inadequate knowledge of the initial management of dental trauma. Specifically, there was a lack of knowledge concerning an appropriate washing and transporting medium and the extra-alveolar period of an avulsed tooth. Due to the inadequate knowledge of PE teachers regarding dental trauma management, specific education should be added to PE classes to improve the emergency treatment of dental injuries.
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- 2019
167. Observing Ramadan and sleep-wake patterns in athletes: a systematic review, meta-analysis and meta-regression
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Omar Boukhris, Hamdi Chtourou, Khaled Trabelsi, Sahar Zlitni, Kais El-Abed, Ahmed Hakim, Nicola Luigi Bragazzi, Aïmen Khacharem, Saber Khanfir, Achraf Ammar, Roy J. Shephard, and Wassim Moalla
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Competitive Behavior ,Time Factors ,Sleep wake ,MEDLINE ,Physical Therapy, Sports Therapy and Rehabilitation ,Islam ,03 medical and health sciences ,Design studies ,0302 clinical medicine ,Sleep Disorders, Circadian Rhythm ,Medicine ,Humans ,Orthopedics and Sports Medicine ,Meta-regression ,biology ,Athletes ,business.industry ,030229 sport sciences ,General Medicine ,Publication bias ,Fasting ,biology.organism_classification ,Sample size determination ,Meta-analysis ,business ,Sleep ,030217 neurology & neurosurgery ,Demography ,Physical Conditioning, Human ,Sports - Abstract
ObjectiveTo evaluate the effect of observing Ramadan on athletes’ sleep patterns.DesignSystematic review and meta-analysis.Data sourcesThe entire content of PubMed/MEDLINE and Web of Science.Eligibility criteria for selecting studiesSingle-group, prepost and cross-over design studies conducted in athletes aged ≥18 years, training at least twice a week and published in English before 12 July 2018 were included. Studies assessing sleep quantity, quality, daytime sleepiness and/or daily naps based on objective or subjective methods were deemed eligible.Study appraisalThe methodological quality was assessed using ‘QualSyst’.ResultsOf 13 selected articles, 7 were of strong quality, 3 were moderate and 3 were weak. 11 studies evaluated total sleep time (TST); this decreased during Ramadan in 4 studies, increased in 1 and remained unchanged in 6. Pooled TST findings indicated a moderate effect size (− 0.97, SE=0.37, 95% CI −1.69 to −0.25, t=−2.64, p=0.01) with significant heterogeneity but no publication bias. Meta-regressions showed no effects of study year, age, sample size, type of sport or competition level, but there were effects of country (with France and Tunisia being the most affected countries and Turkey the least affected, Q=32.14, pConclusionWhen athletes continue to train at least two times/week while observing Ramadan, TST is decreased compared with athletes’ baseline levels.
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- 2019
168. Acute Effects of an 'Energy Drink' on Short-Term Maximal Performance, Reaction Times, Psychological and Physiological Parameters: Insights from a Randomized Double-Blind, Placebo-Controlled, Counterbalanced Crossover Trial
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Achraf Ammar, Nicola Luigi Bragazzi, Roy J. Shephard, Khaled Trabelsi, and Hamdi Chtourou
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Blood Glucose ,Male ,energy drinks ,media_common.quotation_subject ,lcsh:TX341-641 ,Blood Pressure ,Performance-Enhancing Substances ,Anger ,Anxiety ,Athletic Performance ,Profile of mood states ,Placebo ,Article ,03 medical and health sciences ,Young Adult ,0302 clinical medicine ,Double-Blind Method ,Heart Rate ,mood state ,Reaction Time ,Medicine ,Humans ,Wingate test ,media_common ,caffeine ,Nutrition and Dietetics ,Cross-Over Studies ,Hand Strength ,exercise ,business.industry ,Repeated measures design ,030229 sport sciences ,Awareness ,Crossover study ,Affect ,Blood pressure ,Anesthesia ,Exercise Test ,fatigue ,medicine.symptom ,business ,lcsh:Nutrition. Foods and food supply ,030217 neurology & neurosurgery ,Food Science - Abstract
The current study examined the relationships between the effects of consuming a caffeine-containing &ldquo, energy drink&rdquo, upon (i) short-term maximal performance, (ii) reaction times, and (iii) psychological factors (i.e., mood state, ratings of perceived exertion (RPE), and affective load) and on physiological parameters (i.e., blood pressure and blood glucose). A randomized, double-blind, placebo-controlled, counterbalanced crossover design was implemented in this study. Nineteen male physical-education students (age: 21.2 ±, 1.2 years, height: 1.76 ±, 0.08 m, body-mass: 76.6 ±, 12.6 kg) performed two test sessions: after drinking the &ldquo, Red Bull&rsquo, beverage (RB) and after drinking a placebo (PL). One hour after ingestion of each drink, resting blood glucose and blood pressure were measured and the participants completed the Profile of Mood States questionnaire. Then, after a 5-min warm-up, simple visual reaction time and handgrip force were measured, and the 30-s Wingate test was performed. Immediately after these tests, the RPE, blood glucose, and blood pressure were measured, and the affective load was calculated. Differences between treatments were assessed using two-way repeated measures analyses of variance and paired t-tests, as appropriate. Relationships between the test variables were assessed using Bland&ndash, Altman correlations. Significant (i) improvements in peak and mean power output, handgrip force, pre- and post-exercise blood glucose, blood pressure, and vigor and (ii) reductions in reaction times, depression, confusion, fatigue, anger, anxiety, RPE, and affective load scores were observed after RB compared to PL. There were significant correlations of (i) physical performances and reaction times with (ii) RPE, affective load, and pre- and post-exercise blood glucose levels. Gains in peak and mean power were significantly correlated with reductions in fatigue, anxiety (peak power only), and anger (mean power only). The reduction of reaction times was significantly correlated with decreases in confusion and anger and with increases in vigor. Handgrip force and reaction times were significantly correlated with pre- and post-exercise blood pressures. We conclude that RB ingestion has a positive effect on physical performance and reaction times. This effect is related to ergogenic responses in both psychological (i.e., RPE, affective load, and mood state) and physiological (i.e., blood glucose and blood pressure) domains.
- Published
- 2019
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169. Comparison of 2- and 3-Minute Inter-Repetition Rest Periods on Maximal Jerk Technique and Power Maintenance
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Hamdi Chtourou, Anita Hökelmann, Khaled Trabelsi, Osama Abdelkarim, Bryan L. Riemann, Tarak Driss, Marcel Blaumann, and Achraf Ammar
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Adult ,Male ,Competitive Behavior ,Time Factors ,Weight Lifting ,Rest ,030209 endocrinology & metabolism ,Physical Therapy, Sports Therapy and Rehabilitation ,03 medical and health sciences ,Young Adult ,0302 clinical medicine ,Control theory ,Humans ,Orthopedics and Sports Medicine ,Knee ,Mathematics ,Rest (physics) ,Hip ,Repetition (rhetorical device) ,Outcome measures ,Resistance Training ,030229 sport sciences ,General Medicine ,Power (physics) ,Biomechanical Phenomena ,Rest period ,Jerk ,Nephrology ,Motor Skills ,Time and Motion Studies - Abstract
Purpose: The aim of this study was to examine the effect of 3- vs. 2-minute inter maximal-repetition rest period (IMRRP) on maintaining jerk technical efficiency and power production during...
- Published
- 2019
170. Biological Responses to Short-Term Maximal Exercise in Male Police Officers
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Narimen Yousfi, Nizar Souissi, Amine Souissi, Achraf Ammar, Omar Hammouda, Tasnim Masmoudi, Ismail Dergaa, Mohamed Romdhani, Helmi Ben Saad, and Mohamed Saifeddin Fessi
- Subjects
Adult ,Male ,medicine.medical_specialty ,Health (social science) ,Hydrocortisone ,Physical fitness ,Physical exercise ,Hematocrit ,hormonal response ,Melatonin ,Internal medicine ,medicine ,Humans ,Exercise ,Testosterone ,military police ,medicine.diagnostic_test ,business.industry ,Public Health, Environmental and Occupational Health ,inflammatory response ,Police ,hematological response ,short-term exercise ,Cross-Sectional Studies ,Endocrinology ,Sprint ,Physical Fitness ,Medicine ,Original Article ,Hemoglobin ,business ,Anaerobic exercise ,Biomarkers ,medicine.drug - Abstract
The specifics of short-term physical exercise are similar to the immediate reaction demands placed on police officers. Identifying the physiological predisposition to short-term high-intensity exercise in male law enforcement officers will assist in understanding their metabolism and make a significant contribution to a much more personal and individualized workout program. This will improve physical fitness of individual officers, improving their preparedness for such times of emergency. This cross-sectional study was conducted to investigate the responses of hematological (erythrocytes, hemoglobin, hematocrit, leucocytes, monocytes, neutrophils, lymphocytes), hormonal (testosterone, cortisol, melatonin), biochemical (glucose, uric-acid, lactate, creatine-phosphokinase) data to short-term maximal exercise in male police officers ( n = 20). Blood samples were collected before- and after- the running-based anaerobic sprint test (RAST), and biological values were corrected for fluid shifts. Data were mean ± standard deviation of differences (= after minus before RAST). After the RAST, values of cortisol, lactate, neutrophils, lymphocytes, and monocytes increased significantly by 7.01 ± 37.36 mmol/l, 7.55 ± 1.67 mmol/l, 0.17 ± 0.26 103/µl, 0.61 ± 0.28 103/µl, and 0.10 ± 0.13 103/µl, respectively. After the RAST, values of melatonin, uric-acid, creatine-phosphokinase, hemoglobin, and hematocrit decreased significantly by −13.24 ± 4.60 pg/ml, −13.28 ± 14.35 µmol/l, −10.23 ± 10.13 IU/l, −2.01 ± 0.81 g/dl, and −4.46 ± 0.59%, respectively. Biological data of male police officers were affected by sprint test. Understanding changes in biological data following short-term maximal exercise can further assist in a better understanding of anaerobic metabolism, which will be helpful to find available methods for coaches to quantify training loads.
- Published
- 2021
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171. Relationship between biomarkers of muscle damage and redox status in response to a weightlifting training session: effect of time-of-day
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Osama Abdelkarim, Choumous Kallel, Achraf Ammar, Hamdi Chtourou, Fatma Ayedi, N. Souissi, Anita Hoekelmann, Omar Hammouda, and Mouna Turki
- Subjects
Adult ,Male ,medicine.medical_specialty ,Evening ,Weight Lifting ,Bilirubin ,medicine.disease_cause ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Muscular Diseases ,Physiology (medical) ,Internal medicine ,medicine ,Humans ,Muscle, Skeletal ,Exercise ,Morning ,chemistry.chemical_classification ,biology ,business.industry ,Glutathione peroxidase ,Myalgia ,030229 sport sciences ,General Medicine ,Malondialdehyde ,Circadian Rhythm ,Endocrinology ,chemistry ,biology.protein ,Uric acid ,Creatine kinase ,business ,Oxidation-Reduction ,Biomarkers ,030217 neurology & neurosurgery ,Oxidative stress - Abstract
The aims of the present study were to: (1) investigate the effect of a weightlifting training session and time-of-day (TOD) upon biological parameters (i.e., oral temperature, hematological, C-reactive protein (CRP), and oxidative stress) and (2) assess their possible link with muscle damage responses. Nine weightlifters (21 ± 0.5 years) performed, in a randomized order, three Olympic-Weightlifting sessions (i.e., at 08:00, 14:00, and 18:00). Blood samples were collected at rest, 3 min and 48 h after each training session. Between pre- and post-training session, ANOVA showed significant increases in oxidative stress markers at the three TODs (p
- Published
- 2016
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172. Practical Recommendations for Maintaining Active Lifestyle during the COVID-19 Pandemic: A Systematic Literature Review
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Khaled Trabelsi, Hamdi Chtourou, Daniella How, Mona A. Ahmed, Ellen Bentlage, Achraf Ammar, and Michael Brach
- Subjects
Gerontology ,Isolation (health care) ,social isolation ,Health, Toxicology and Mutagenesis ,Pneumonia, Viral ,Population ,physical activity ,lcsh:Medicine ,Review ,Health Promotion ,Betacoronavirus ,03 medical and health sciences ,0302 clinical medicine ,Pandemic ,medicine ,Humans ,030212 general & internal medicine ,Social isolation ,education ,Exercise ,Life Style ,Pandemics ,Rating of perceived exertion ,education.field_of_study ,SARS-CoV-2 ,pandemic ,lcsh:R ,quarantine ,Public Health, Environmental and Occupational Health ,COVID-19 ,Systematic review ,Health promotion ,Scale (social sciences) ,recommendations ,medicine.symptom ,Coronavirus Infections ,Psychology ,030217 neurology & neurosurgery - Abstract
Diminished volumes of habitual physical activity and increased sedentary levels have been observed as a result of COVID-19 home-confinement. Consequences of inactivity, including a higher mortality rate and poorer general health and fitness, have been reported. This systematic review aimed to provide practical recommendations for maintaining active lifestyles during pandemics. In May 2020, two electronic databases (PubMed; Web of Science) were used to search for relevant studies. A total of 1206 records were screened by two researchers. Thirty-one relevant studies were included in this systematic review, in which the methodological quality was assessed. With regard to six studies, which explicitly dealt with physical activity during COVID-19, the evidence level is classified by three articles to level II, and in the other three to level VI. Regarding the physical activity recommendations in these papers, three of them were classified to a medium, and the same number to a weak evidence base. Of the 25 papers which refer to other pandemics and/or isolation situations, one was classified to evidence level I, four were ranged to level II, three to level III, one to level V, and the others to level VI. This systematic review revealed that reduced physical activity levels are of serious concern during home confinement in pandemic times. The recommendations provided by many international organizations to maintain active lifestyles during these times mainly target the general population, with less consideration for vulnerable populations (e.g., older adults, people with health issues). Therefore, personalized and supervised physical activity programs are urgently needed, with the option to group-play physical activity programs (e.g., exergames). These can be assisted, delivered, and disseminated worldwide through information and communication technology solutions. If it is permitted and safe, being active outside in daylight is advised, with an effort level of mild to moderate using the rating of perceived exertion scale. Relaxation techniques should be integrated into the daily routine to reduce stress levels. On the evidence base and levels of the included articles in this review, the results need to be interpreted with caution. Given that policies are different across regions and countries, further research is needed to categorize recommendations according to different social-distancing scenarios.
- Published
- 2020
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173. Effects of the 5-m Shuttle Run Test on Markers of Muscle Damage, Inflammation, and Fatigue in Healthy Male Athletes
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Achraf Ammar, Khadijah Irandoust, Morteza Taheri, Omar Boukhris, Mouna Turki, Jordan M. Glenn, Hsen Hsouna, Fatma Ayadi, Raouf Abdessalem, Florian Azad Engel, Hamdi Chtourou, Khaled Trabelsi, Nicholas T. Bott, and Nicola Luigi Bragazzi
- Subjects
Adult ,Male ,repeated sprint ,medicine.medical_specialty ,Adolescent ,Health, Toxicology and Mutagenesis ,lcsh:Medicine ,Physical exercise ,Inflammation ,Muscle damage ,Article ,Young Adult ,03 medical and health sciences ,chemistry.chemical_compound ,muscle damage ,0302 clinical medicine ,Internal medicine ,Lactate dehydrogenase ,Delayed onset muscle soreness ,medicine ,Humans ,Muscle, Skeletal ,muscle soreness ,Shuttle run test ,biology ,business.industry ,lcsh:R ,Public Health, Environmental and Occupational Health ,Myalgia ,030229 sport sciences ,Endocrinology ,chemistry ,Athletes ,Blood biomarkers ,biology.protein ,fatigue ,Creatine kinase ,medicine.symptom ,business ,human activities ,Biomarkers ,030217 neurology & neurosurgery - Abstract
Physical exercise is often associated with increases in muscle damage markers and inflammation. However, biomarkers of muscle damage and inflammation responses to the 5-m shuttle run test (5mSRT) have not yet been evaluated. The aim of the present study was to investigate effects of the 5mSRT on muscle damage markers, inflammation, and perception of fatigue and recovery in healthy male athletes. Fifteen male amateur team sports players (age: 20 ±, 3 yrs, height: 173 ±, 7 cm, body-mass: 67 ±, 7 kg) participated in this study. Blood biomarkers were collected at rest, 5 min after, and 72 h after the 5mSRT to measure muscle damage (i.e., creatinine kinase (CK), lactate dehydrogenase (LDH), aspartate aminotransferase (ASAT), and alanine aminotransferase (ALAT)) and inflammation (i.e., C-reactive protein (CRP)). Best distance (BD), total distance (TD), fatigue index (FI), and percentage decrement (PD) during the 5mSRT were assessed. Perceived recovery (PRS) and delayed onset muscle soreness (DOMS) were recorded before, 5 min after, and 72 h after the 5mSRT, perceived exertion (RPE) was recorded before, during, and 72 h after the 5mSRT. Muscle damage biomarkers post 5mSRT showed a significant increase compared to pre 5mSRT (p <, 0.001) levels ((i.e., CK (190.6 ±, 109.1 IU/L vs. 234.6 ±, 113.7 IU/L), LDH (163.6 ±, 35.1 IU/L vs. 209.9 ±, 50.8 IU/L), ASAT (18.0 ±, 4.4 IU/L vs. 21.7 ±, 6.2 IU/L), and ALAT (10.2 ±, 3.4 IU/L vs. 12.7 ±, 3.8 IU/L)) and 72 h post 5mSRT (p <, 0.001) levels ((CK (125.3 ±, 80.5 IU/L vs. 234.6 ±, 113.7 IU/L), LDH (143.9 ±, 36.6 IU/L vs. 209.9 ±, 50.8 IU/L), ASAT (15.0 ±, 4.7 IU/L vs. 21.7 ±, 6.2 IU/L), and ALAT (8.6 ±, 2.4 IU/L vs. 12.7 ±, 3.8 IU/L)). CRP was also significantly higher post 5mSRT compared to pre 5mSRT (2.1 ±, 2.5 mg/L vs. 2.8 ±, 3.3 mg/L, p <, 0.001) and 72 h post 5mSRT (1.4 ±, 2.3 mg/L vs. 2.8 ±, 0.001). Significant correlations were reported between (i) physical performance parameters (i.e., PD, FI, TD, and BD), and (ii) markers of muscle damage (i.e., CK, LDH, ASAT, and ALAT) and inflammation (i.e., CRP). Similarly, DOMS and RPE scores were significantly higher post 5mSRT compared to pre 5mSRT (2.4 ±, 1.0UA vs. 6.7 ±, 1.1UA and 2.1 ±, 0.6 UA vs. 8.1 ±, 0.6 UA, respectively p <, 0.001) and 72 h post 5mSRT (1.9 ±, 0.7 UA vs. 6.7 ±, 1.1 UA and 1.5 ±, 0.001). PRS scores were significantly lower post 5mSRT as compared to pre 5mSRT (6 ±, 1 UA vs. 3 ±, 1 UA, p <, 0.001) and 72 h post 5mSRT (7 ±, 0.001). Significant correlations existed between (i) performance parameters (PD, FI, TD, and BD) and (ii) RPE, PRS, and DOMS. The 5mSRT increased biomarkers of muscle damage and inflammation, as well as the DOMS and RPE and reduced the PRS. Seventy-two hours was sufficient for fatigue recovery induced by the 5mSRT. PD is better than FI for the calculation of performance decrements during the 5mSRT to represent fatigue.
- Published
- 2020
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174. COVID‐19, physical (in‐)activity, and dementia prevention
- Author
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Müller, Patrick, primary, Achraf, Ammar, additional, Zou, Liye, additional, Apfelbacher, Christian, additional, Erickson, Kirk I., additional, and Müller, Notger G., additional
- Published
- 2020
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175. Effects of Practicing Physical Activity During Ramadan Fasting on Health-Related Indices: An Updated Brief Review
- Author
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Achraf Ammar, Khaled Trabelsi, Omar Boukhris, Hamdi Chtourou, Ahmed Hakim, Wassim Moalla, and Kais El-Abed
- Subjects
Gerontology ,business.industry ,Physical activity ,Health related ,Blood lipids ,Physical exercise ,030229 sport sciences ,biochemical phenomena, metabolism, and nutrition ,bacterial infections and mycoses ,03 medical and health sciences ,Fluid intake ,0302 clinical medicine ,Metabolic markers ,Intermittent fasting ,polycyclic compounds ,bacteria ,Medicine ,heterocyclic compounds ,business ,030217 neurology & neurosurgery - Abstract
Based on Moon observation, every year, adults healthy Muslims practiced Ramadan intermittent fasting (RIF) for 29 or 30 consecutive days. During RIF Muslims are allowed to food and fluid intake only during night (from sunset to sunrise). Thus, behavioral changes are observed during RIF (e.g., food and sleep habits). Despite these changes, many healthy Muslims maintain their normal habitual physical exercise practice during RIF. However, changes in blood lipids, metabolic markers, electrolytes and hematological parameters during RIF in practitioners of physical activity are yet poorly studied. Therefore, the present review article will summarize the health specific effects of RIF in subjects engaged in physical training during Ramadan.
- Published
- 2018
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176. Effect of 2- vs. 3-Minute Interrepetition Rest Period on Maximal Clean Technique and Performance
- Author
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Bryan L. Riemann, Achraf Ammar, Tarak Driss, Osama Abdelkarim, and Anita Hökelmann
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Adult ,Male ,Weight Lifting ,Movement ,Rest ,Physical Therapy, Sports Therapy and Rehabilitation ,Perceived exertion ,030204 cardiovascular system & hematology ,03 medical and health sciences ,Young Adult ,0302 clinical medicine ,Animal science ,Rest (finance) ,Maximal strength ,Humans ,Orthopedics and Sports Medicine ,Power output ,Muscle Strength ,Muscle, Skeletal ,Mathematics ,Vertical ground reaction force ,Resistance Training ,030229 sport sciences ,General Medicine ,Biomechanical Phenomena ,Rest period - Abstract
Ammar, A, Riemann, BL, Abdelkarim, O, Driss, T, and Hökelmann, A. Effect of 2- vs. 3-minute interrepetition rest period on maximal clean technique and performance. J Strength Cond Res 34(9): 2548-2556, 2020-Currently, it is widely accepted that adopting a long rest period (3-5 minutes) during maximal strength and power exercise is of importance in reducing acute fatigue and maintaining power and technique proficiency. However, despite the fact that weightlifting is an example of maximal strength exercise, only 2 minutes are officially allowed when athletes attempt 2 successive lifts. The purpose of this study was to compare 3- vs. 2-minute intermaximal repetition rest periods (IMRRPs) on performance, rate of perceived exertion (RPE), technical efficiency, and power production during 2 successive maximal repetitions of cleanjerk (CJ). Nine elite weightlifters (age: 24.4 ± 3.6 years, body mass: 77.2 ± 7.1 kg, height 176.0 ± 6.4 cm, and 1 repetition maximum CJ: 170.0 ± 5.0 kg) performed 2 separate testing sessions using 2-minute IMRRP (IMRRP-2) and 3-minute IMRRP (IMRRP-3), in a randomized order, while barbell kinematics and kinetics were recorded. Results showed that the longer IMRRP-3 minutes led to the maintenance of clean technique (from the first to the second repetition) evidenced by a 1.86% lower decline in peak vertical displacement (p = 0.03) and attenuation of increased peak horizontal displacements with a 1.74% (p = 0.03) less backward movement during the first pull, a 3.89% (p = 0.008) less forward movement during the second pull, and a 4.7% (p = 0.005) less backward movement during the catch phase. In addition, attenuation of peak velocity (2.22%; p = 0.02), peak vertical ground reaction force (1.70%; p = 0.03), and peak power (2.14%; p = 0.02) declines were shown using IMRRP-3 compared with IMRRP-2. Increasing IMRRP from 2 to 3 minutes was also shown to decrease RPE values (8.02%; p = 0.008) and to enhance supramaximal CJ performance (1.55%; p = 0.003). The results of this study suggest 3 minutes to be the most advantageous IMRRP in terms of maintaining technical efficiency, power output, reducing fatigue perception, and enhancing performance in elite weightlifters.
- Published
- 2018
177. Acute and delayed responses of steroidal hormones, blood lactate and biomarkers of muscle damage after a resistance training session: time-of-day effects
- Author
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Hamdi Chtourou, Omar Hammouda, Tarak Driss, Mariem Boudaya, Ahmed Chaari, Mouna Turki, Nizar Souissi, Achraf Ammar, and Fatma Ayedi
- Subjects
Adult ,Male ,medicine.medical_specialty ,Time Factors ,Evening ,Hydrocortisone ,Anabolism ,Rest ,Physical Therapy, Sports Therapy and Rehabilitation ,Upper Extremity ,Young Adult ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Internal medicine ,Lactate dehydrogenase ,medicine ,Humans ,Testosterone ,Orthopedics and Sports Medicine ,Circadian rhythm ,Muscle, Skeletal ,Creatine Kinase ,Morning ,L-Lactate Dehydrogenase ,biology ,business.industry ,Diurnal temperature variation ,Resistance Training ,030229 sport sciences ,Circadian Rhythm ,Endocrinology ,Lower Extremity ,chemistry ,Lactates ,biology.protein ,Creatine kinase ,business ,Biomarkers ,030217 neurology & neurosurgery ,Hormone - Abstract
BACKGROUND The present study aimed to investigate the effect of time-of-days (TOD) on some biochemical and hormonal responses after resistance training sessions. METHODS Ten trained subjects (22±2 years) performed, in randomized order, three resistance-training-sessions at 7 a.m., 1 p.m. and 5 p.m. Each training-session included six upper and lower body resistance exercises with 3×10 repetitions. Blood lactate (Lac), creatine kinase (CK), lactate dehydrogenase (LDH), cortisol (C) and testosterone (T) were collected at rest, 3 min and 48 h after each-session. RESULTS At rest, steroidal hormones were higher in the morning compared to the evening (P
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- 2018
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178. Acute and delayed responses of steroidal hormones after a resistance training session: time-of-day effects
- Author
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Faten Haj Kacem, Mohamed Abid, Achraf Ammar, Mouna Turki, Manel Naifar, and Fatma Ayedi
- Subjects
Time of day ,Steroidal hormones ,business.industry ,Resistance training ,Physiology ,Medicine ,Session (computer science) ,business - Published
- 2018
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179. Free throw shot in basketball: kinematic analysis of scored and missed shots during the learning process
- Author
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Hamdi Chtourou, Achraf Ammar, Osama Abdelkarim, Anita Hoekelmann, and Anthony Parish
- Subjects
medicine.medical_specialty ,Basketball ,biology ,Sports medicine ,Athletes ,Shot (filmmaking) ,Significant difference ,030229 sport sciences ,02 engineering and technology ,Kinematics ,021001 nanoscience & nanotechnology ,biology.organism_classification ,03 medical and health sciences ,0302 clinical medicine ,Physical medicine and rehabilitation ,medicine ,Orthopedics and Sports Medicine ,Statistical analysis ,0210 nano-technology ,Psychology ,human activities ,Free throw - Abstract
The aims of the present study were to analyze selected kinematical parameters of free throw shooting in basketball performed during the learning process and identify which one has a greater effect on success. Fifteen FT attempts performed by 10 male college sports students were recorded with a high-speed camera (200 Hz) and analyzed using the system software SIMI-Motion. Statistical analysis showed that the knee angle helped determine success in FT shooting. Comparing various body angles effect on missed to scored baskets, only knee angles showed a significant difference with a higher value in scored baskets (p
- Published
- 2015
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180. Acute and delayed responses of C-reactive protein, malondialdehyde and antioxidant markers after resistance training session in elite weightlifters: Effect of time of day
- Author
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Achraf Ammar, Hamdi Chtourou, Omar Hammouda, Jihen Chiboub, Mamdouh Ben Ali, Mouna Turki, Khaled Trabelsi, Osama Abdelkarim, Kais El Abed, Anita Hoekelmann, and Nizar Souissi
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Male ,medicine.medical_specialty ,Time Factors ,Evening ,Weight Lifting ,Physiology ,Athletic Performance ,Antioxidants ,Lipid peroxidation ,Random Allocation ,Young Adult ,chemistry.chemical_compound ,Malondialdehyde ,Physiology (medical) ,Internal medicine ,medicine ,Humans ,Circadian rhythm ,Morning ,chemistry.chemical_classification ,biology ,business.industry ,Glutathione peroxidase ,C-reactive protein ,Resistance Training ,Circadian Rhythm ,Oxidative Stress ,C-Reactive Protein ,Endocrinology ,chemistry ,biology.protein ,Uric acid ,Lipid Peroxidation ,business ,Biomarkers - Abstract
The aim of this study was to investigate the effect of an Olympic-Weightlifting-session followed by 48-h recovery period on the oxidative and antioxidant parameters' diurnal variation. Nine weightlifters (21 ± 0.5 years) performed, in randomized order, three Olympic-Weightlifting-sessions at 08 h:00, 14 h:00 and 18 h:00. Blood samples were collected: at rest and 3 min and 48 h after each session. C-reactive protein (CRP), rate of lipid peroxidation and antioxidant activities were assessed. At rest, analysis of variance showed a significant time of day (TOD) effect (p
- Published
- 2015
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181. Post-resistance training detraining: time-of-day effects on training and testing outcomes
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Anis Chaouachi, Hamdi Chtourou, Karim Chamari, Osama Abdel Karim, Nizar Souissi, Pantelis T. Nikolaidis, and Achraf Ammar
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medicine.medical_specialty ,Evening ,Physiology ,business.industry ,education ,Resistance training ,Training (meteorology) ,Squat ,Test (assessment) ,Time of day ,Physical medicine and rehabilitation ,Physiology (medical) ,Physical therapy ,Medicine ,business ,Leg press ,Ecology, Evolution, Behavior and Systematics ,Morning - Abstract
The aim of this study was to examine the effects of 3 and 5 weeks of detraining after 14 weeks of resistance training at a specific time of day on performances during the squat jump (SJ) and the maximal voluntary contraction (MVC). Thirty-one healthy male physical education students (age: 23.1 ± 1.0 years; height: 176.1 ± 6.3 cm; weight: 74.9 ± 10.9 kg) were randomly assigned to either a morning training group (MTG, training between 07:00 and 08:00 h, n = 10), an evening training group (ETG, training between 17:00 and 18:00 h, n = 11) or a control group (CG, no training, n = 10). Participants then performed eight test sessions (twice per day, at 07:00 and 17:00 h) over the course of four phases: during pre-training, immediately post-training, and after 3 and 5 weeks of detraining. Before each test session, oral temperature was recorded. During the first 12 weeks of resistance training, participants performed 3 sets of 10 repetitions to failure (10-RM) for 4 exercises (squat, leg press, leg extension and l...
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- 2015
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182. Prevalence of overweight and obesity and possible effect of intervention program: Tunisian children as model
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Anthony Parish, Anita Hoekelmann, Osama Abdel Karim, Hamdi Chtourou, and Achraf Ammar
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Gerontology ,education.field_of_study ,medicine.medical_specialty ,business.industry ,Public health ,Population ,Psychological intervention ,Context (language use) ,Overweight ,medicine.disease ,Obesity ,Health promotion ,Intervention (counseling) ,medicine ,Orthopedics and Sports Medicine ,medicine.symptom ,business ,education - Abstract
The potential benefits from the reduction of excessive weight levels among the general population are of considerable public health importance. Early intervention against selected risk factors is a principle key in the prevention of chronic diseases. In this context, a number of school-based interventions to promote healthy lifestyles have been implemented globally in response to the WHO health promotion initiatives. In Tunisia, most studies have primarily focused on the principal determinants of overweight and obese school children. A number of intervention programs for school children have been implemented in different regions and similarly show that supplemental educative program interventions result in only substantive improvements with regard to knowledge, and behavior intent, in the children intervention group (p
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- 2015
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183. A Comparative Study of Physical Fitness among Egyptian and German Children Aged Between 6 and 10 Years
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Klaus Bös, Hamdi Chtourou, Achraf Ammar, Anita Hökelmann, Tarek Gaber, Osama Abdel Karim, L. Schlenker, Matthias Wagner, and Anthony Parish
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medicine.medical_specialty ,business.industry ,Physical fitness ,Ethnic group ,General Medicine ,language.human_language ,Rate of increase ,German ,language ,Physical therapy ,Motor Development, Physical Fitness, Anthropometric Parameters, PE Curriculum ,Medicine ,Analysis of variance ,ddc:796 ,business ,Body mass index ,Volunteer ,Motor skill ,Demography - Abstract
The aim of the present study was to compare the physical fitness of Egyptian (n = 403) and German (n = 1712) volunteer children aged between 6 and 10 years. The German motor test (DMT), height, weight, and body mass index (BMI) were measured. ANOVA showed that the results of the motor performance ability (MPA) were affected by the ethnicity with higher performance for German children (p < 0.05). German children’s superiority in strength is present from the age of 6 years (p < 0.001 for the Push-Ups and p < 0.05 for the Long Jumping), to the age of 10 years (p < 0.001 and p < 0.01, respectively). However, their superiority in coordination ability was observed only in school aged children (p < 0.05 and p > 0.05, respect to 6 and 10 years old). With maturation from six to ten years, the achievement level for both populations show a positive improvement in the coordination and strength, and reduction in the flexibility (p < 0.001), with a higher rate of increase for the German children, except boys in the Push-Ups. Therefore, more strength-oriented physical activities before the age of 6 years and coordination-oriented activities between 6 and 8 years are recommended for Egyptian PE curriculum.
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- 2015
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184. Relationship between motor and cognitive learning abilities among primary school-aged children
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Hamdi Chtourou, Anita Hökelmann, Osama Abdelkarim, Elke Knisel, Matthias Wagner, Klaus Bös, and Achraf Ammar
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business.industry ,Physical fitness ,lcsh:R ,lcsh:Medicine ,Cognition ,030229 sport sciences ,General Medicine ,Academic achievement ,Child development ,Test (assessment) ,Developmental psychology ,Intellectual performance ,03 medical and health sciences ,0302 clinical medicine ,Physical fitness Intellectual performance Child development ,Cognitive development ,Medicine ,Effects of sleep deprivation on cognitive performance ,ddc:796 ,business ,Association (psychology) ,030217 neurology & neurosurgery - Abstract
Background: The relationship between motor and cognitive development has already been proven in young children. However, in relation to the academic achievement the association between motor and cognitive performance still not well established. Therefore, the aim of this study was to examine the levels of motor and cognitive learning abilities and their independent and combined associations among German primary school-children.Methods: Participants were (n = 197) between the ages of six to eight. The German motor test (DMT), the cognitive abilities test (KFT), height, weight, and body mass index (BMI) were measured.Results: ANOVA testing found that boys perform better in long jumping and in the six minutes running test while girls perform better in balancing backwards and in deductive thinking test (p < 0.05). With maturation from ages six to eight the achievement level of both populations showed a higher performance in motor and cognitive learning abilities (p < 0.001). Concerning the combined and independent associations between the tested abilities, a significant correlation was shown between total motor and total cognitive learning abilities (p < 0.001, r = 0.60) with higher contribution of balancing backwards, six minutes running and push-up levels (r = 0.63, r = 0.62, r = 0.60, respectively) in the performance of the cognitive learning abilities (i.e. mathematical thinking, r = 0.62 and language understanding, r = 0.59).Conclusions: In conclusion, fostering the childrens’ physical fitness during the primary school age could enhance both motor and cognitive learning abilities related to the academic achievement. published
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- 2017
185. Kinetic and kinematic patterns during high intensity clean movement: searching for optimal load
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Marcel Blaumann, Bryan L. Riemann, Achraf Ammar, Osama Abdelkarim, Anita Hökelmann, and Liwa Masmoudi
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Adult ,Male ,Weight Lifting ,Acceleration ,Physical Therapy, Sports Therapy and Rehabilitation ,Kinematics ,Athletic Performance ,Kinetic energy ,Displacement (vector) ,03 medical and health sciences ,Young Adult ,0302 clinical medicine ,Rate of force development ,Statistics ,Humans ,Orthopedics and Sports Medicine ,Force platform ,Muscle Strength ,Muscle, Skeletal ,Simulation ,Mathematics ,Work (physics) ,030229 sport sciences ,Power (physics) ,Biomechanical Phenomena ,030217 neurology & neurosurgery - Abstract
The aim of the present study was to investigate loading effects on kinematic and kinetic variables among elite-weightlifters in order to identify an optimal training load to maximize power production for clean-movement. Nine elite-weightlifter (age: 24 ± 4years, body-mass: 77 ± 6.5kg, height: 176 ± 6.1cm and 1RM clean: 170 ± 5kg) performed 2 separate repetitions of the clean using 85, 90, 95% and 100%, in a randomized order, while standing on a force platform and being recorded using 3D-capture-system. Differences in kinematics (barbell displacement, velocity and acceleration) and kinetics (power, vertical ground reaction force (vGRF), rate of force development (RFD), and work) across the loads were statistically assessed. Results revealed significant load effects for the majority of the studied parameters (p0.01) and showed that typical bar-displacement, greatest bar-velocity and peak-power were achieved at 85 and 90% 1RM (p0.001). Additionally greater average power was shown for 90 and 95% (p0.01) and greater work and vGRF were shown for 90, 95 and 100% than 85% 1RM (p0.05). Load had no significant effect on peak-vGRF and peak-RFD (p0.05). The results of this study, suggest 90% 1RM to be the most advantageous load to train explosive-force and to enhance power-outputs while maintaining technical efficiency in elite-weightlifters.
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- 2017
186. Effects of Pomegranate Juice Supplementation on Oxidative Stress Biomarkers Following Weightlifting Exercise
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Anita Hoekelmann, Nizar Souissi, Khaled Trabelsi, Tarak Driss, Stephen J. Bailey, Sourour Yaich, Mohamed Bouaziz, Mouna Turki, Fatma Ayadi, Omar Hammouda, Osama Abdelkarim, Achraf Ammar, and Hamdi Chtourou
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0301 basic medicine ,Male ,Antioxidant ,antioxidant ,medicine.medical_treatment ,medicine.disease_cause ,Lipid peroxidation ,chemistry.chemical_compound ,0302 clinical medicine ,Malondialdehyde ,chemistry.chemical_classification ,Lythraceae ,Nutrition and Dietetics ,Cross-Over Studies ,Glutathione peroxidase ,lipid peroxidation ,Catalase ,Fruit and Vegetable Juices ,lcsh:Nutrition. Foods and food supply ,medicine.medical_specialty ,Weight Lifting ,Bilirubin ,Rest ,lcsh:TX341-641 ,Placebo ,Article ,03 medical and health sciences ,Young Adult ,power training ,Internal medicine ,polyphenol ,medicine ,Humans ,Muscle, Skeletal ,Exercise ,Glutathione Peroxidase ,030109 nutrition & dietetics ,business.industry ,030229 sport sciences ,Surgery ,Sports Nutritional Physiological Phenomena ,Oxidative Stress ,Endocrinology ,chemistry ,Uric acid ,business ,Oxidative stress ,Biomarkers ,Food Science - Abstract
The aim of this study was to test the hypothesis that pomegranate juice supplementation would blunt acute and delayed oxidative stress responses after a weightlifting training session. Nine elite weightlifters (21.0 ± 1 years) performed two Olympic-Weightlifting sessions after ingesting either the placebo or pomegranate juice supplements. Venous blood samples were collected at rest and 3 min and 48 h after each session. Compared to the placebo condition, pomegranate juice supplementation attenuated the increase in malondialdehyde (−12.5%; p < 0.01) and enhanced the enzymatic (+8.6% for catalase and +6.8% for glutathione peroxidase; p < 0.05) and non-enzymatic (+12.6% for uric acid and +5.7% for total bilirubin; p < 0.01) antioxidant responses shortly (3 min) after completion of the training session. Additionally, during the 48 h recovery period, pomegranate juice supplementation accelerated (p < 0.05) the recovery kinetics of the malondialdehyde (5.6%) and the enzymatic antioxidant defenses compared to the placebo condition (9 to 10%). In conclusion, supplementation with pomegranate juice has the potential to attenuate oxidative stress by enhancing antioxidant responses assessed acutely and up to 48 h following an intensive weightlifting training session. Therefore, elite weightlifters might benefit from blunted oxidative stress responses following intensive weightlifting sessions, which could have implications for recovery between training sessions.
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- 2017
187. Effect of different nap opportunity durations on short-term maximal performance, attention, feelings, muscle soreness, fatigue, stress and sleep
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Hamdi Chtourou, Omar Boukhris, Achraf Ammar, Hsen Hsouna, Raouf Abdessalem, Roy J. Shephard, and Khaled Trabelsi
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Male ,medicine.medical_specialty ,Adolescent ,media_common.quotation_subject ,Emotions ,Experimental and Cognitive Psychology ,Athletic Performance ,Neuropsychological Tests ,Young Adult ,03 medical and health sciences ,Behavioral Neuroscience ,0302 clinical medicine ,Surveys and Questionnaires ,mental disorders ,Humans ,Medicine ,Attention ,0501 psychology and cognitive sciences ,Fatigue stress ,050102 behavioral science & comparative psychology ,Fatigue ,media_common ,business.industry ,musculoskeletal, neural, and ocular physiology ,fungi ,05 social sciences ,Myalgia ,Sleep in non-human animals ,Nap ,Mood ,Feeling ,Physical performance ,Exercise Test ,Physical therapy ,Sleep ,business ,human activities ,Stress, Psychological ,psychological phenomena and processes ,030217 neurology & neurosurgery - Abstract
The aim of the present study was to determine the effect of different nap opportunity durations on short-term maximal performance, attention, feelings, muscle soreness, fatigue, stress and sleep. Twenty physically active men (age: 21.1 ± 3.6 years, height: 176.4 ± 5.7 cm, body-mass: 72 ± 10.8 kg) performed the 5-jump and the digit-cancellation (i.e., attention) tests after four randomized nap opportunity conditions: no-nap opportunity (N0), 25 min of nap opportunity (N25), 35 min of nap opportunity (N35) and 45 min of nap opportunity (N45). Subjective measurement of feelings, muscle soreness, fatigue, stress and sleep were performed during each test session. Compared to N0, there was a significant improvement of the 5-jump performance during N35 (Δ = +3.5%, p
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- 2019
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188. Sleep Patterns, Alertness, Dietary Intake, Muscle Soreness, Fatigue, and Mental Stress Recorded before, during and after Ramadan Observance
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Hamdi Chtourou, Omar Boukhris, Khaled Trabelsi, Achraf Ammar, Hsen Hsouna, Nicola Luigi Bragazzi, Roy J. Shephard, Raouf Abdessalem, and Lassaad Chtourou
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medicine.medical_specialty ,Physical Therapy, Sports Therapy and Rehabilitation ,Article ,Pittsburgh Sleep Quality Index ,lcsh:GV557-1198.995 ,03 medical and health sciences ,0302 clinical medicine ,Mental stress ,Intermittent fasting ,medicine ,Orthopedics and Sports Medicine ,lcsh:Sports ,Sleep disorder ,Sleep quality ,intermittent fasting ,business.industry ,Dietary intake ,sleep patterns ,030229 sport sciences ,medicine.disease ,Sleep patterns ,Alertness ,nutrition ,Physical therapy ,fatigue ,sense organs ,business ,030217 neurology & neurosurgery - Abstract
Ramadan is one of the pillars of the Islamic creed. Its observance commonly causes chrono-biological changes. The present study examined sleep and alertness during Ramadan observance relative to data collected before and after Ramadan in a sample of young, physically active men. Information was also collected on dietary intake, muscle soreness, fatigue, and mental stress over the three periods. Fourteen physically active men (age: 21.6 ±, 3.3 years, height: 1.77 ±, 0.06 m, body-mass: 73.1 ±, 9.0 kg) completed the Hooper questionnaire and the Pittsburgh Sleep Quality Index (PSQI) and responded to the digit cancellation test (DCT) fifteen days before Ramadan, during the last ten days of Ramadan and 20 days after Ramadan. The PSQI results indicated that sleep duration was significantly longer before Ramadan (p = 0.003) and after Ramadan (p = 0.04) compared to during Ramadan and was longer before Ramadan than after Ramadan (p = 0.04). In addition, the sleep efficiency was lower during Ramadan in comparison to before Ramadan (p = 0.02) and after Ramadan (p = 0.04). The daytime dysfunction score increased during Ramadan in comparison with before Ramadan (p = 0.01) and after Ramadan (p = 0.04), and the sleep quality score was higher during (p = 0.003) and after Ramadan (p = 0.04) as compared to before Ramadan. The sleep disturbance score increased during Ramadan relative to before Ramadan (p = 0.04). However, Ramadan observance had no significant effect on sleep latency. Mental alertness also decreased at the end of Ramadan compared to before (p = 0.003) or after Ramadan (p = 0.01). Dietary intake, muscle soreness, fatigue, and mental stress as estimated by the Hooper questionnaire remained unchanged over the three periods of the investigation (p >, 0.05). In conclusion, Ramadan observance had an adverse effect on sleep quantity and on mental alertness, but not on sleep quality. However, dietary intake, muscle soreness, fatigue, and mental stress remained unaffected.
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- 2019
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189. Effect of Time-of-Day on Biochemical Markers in Response to Physical Exercise
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Achraf Ammar, Nizar Souissi, and Hamdi Chtourou
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medicine.medical_specialty ,Evening ,Rest ,Population ,Physical Therapy, Sports Therapy and Rehabilitation ,Context (language use) ,Physical exercise ,Athletic Performance ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,medicine ,Humans ,Orthopedics and Sports Medicine ,Circadian rhythm ,Exercise physiology ,education ,Exercise ,Morning ,education.field_of_study ,Hematologic Tests ,Diurnal temperature variation ,030229 sport sciences ,General Medicine ,Circadian Rhythm ,Endocrinology ,Psychology ,030217 neurology & neurosurgery ,Biomarkers ,Sports - Abstract
Ammar, A, Chtourou, H, and Souissi, N. Effect of time-of-day on biochemical markers in response to physical exercise. J Strength Cond Res 31(1): 272-282, 2017-It is well established that many physiological functions are time-of-day (TOD) dependent, and their circadian rhythms are well documented in healthy populations at resting state. In fact, greater rate of oxidative stress, white blood cell, homocysteine, and muscle damage markers were shown in the early evening (≈18:00 hours), and more efficient antioxidant activity was observed in the early morning (≈06:00 hours). During physical tasks, the majority of the above-mentioned physiological functions increase from pre to post physical exercise with different rates of increases from morning to evening. These different rates of increases are suggested to alter the physiological resting diurnal variation. In this context, given the possible significant interaction "TOD × physical exercise," circadian rhythms of the physiological responses during physical activity are still not well established in trained subjects. Otherwise, it was suggested that the diurnal variation of these biochemical parameters could, in part, explain the typical diurnal fluctuation of physical performance. Therefore, the aim of this review was to summarize the currently available studies investigating the circadian rhythms of physiological functions at rest and after physical exercise and to establish their possible effect on the diurnal variation of sport performance. Although studies in this field are limited, the available information shows that compared with sedentary subjects, trained population maintained similar diurnal variations of hematological parameters, homocysteine, and some biochemical markers at rest and even after physical exercise. However, after strength exercises, the circadian rhythms for the majority of oxidative stress and muscle damage markers were altered because of the higher rate of increased pre-post exercises registered in the morning compared with the afternoon and evening. The available studies reveal that the significant circadian variation observed for sport performances could be more likely explained by the alteration of ionic movement and the diurnal fluctuation of homocysteine, lactate, muscle damage, and antioxidant markers.
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- 2016
190. Short versus long small-sided game training during Ramadan in soccer players
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Hana Baklouti, Nizar Souissi, Achraf Ammar, Olivier Girard, Hamdi Chtourou, Hamdi Jaafar, Asma Aloui, and Noureddine Rejeb
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Male ,medicine.medical_specialty ,Tunisia ,Physical Therapy, Sports Therapy and Rehabilitation ,Field tests ,Athletic Performance ,Profile of mood states ,Islam ,03 medical and health sciences ,Young Adult ,0302 clinical medicine ,Surveys and Questionnaires ,Soccer ,Medicine ,Humans ,Orthopedics and Sports Medicine ,Training load ,Rating of perceived exertion ,Physical Education and Training ,biology ,business.industry ,Athletes ,Outcome measures ,030229 sport sciences ,General Medicine ,Fasting ,biology.organism_classification ,Test (assessment) ,Physical performance ,Case-Control Studies ,Physical therapy ,business ,030217 neurology & neurosurgery - Abstract
To compare the effects of two small-sided game (SSG) training formats (4 × 4 min (SSG-S) and 2 × 8 min (SSG-L)) conducted during Ramadan on Hoff and five-jump (5JT) tests' performances and session rating of perceived exertion (sRPE).Three group, case-control.Field tests.Twenty-four male soccer players were divided into 3 groups: 2 groups undertaking 4 weeks of SSG-S (n = 8) or SSG-L (n = 8) during Ramadan and a control group (n = 8).The Profile of Mood States (POMS) and Hooper questionnaires' scores and 5JT and Hoff test's performances were measured before (BR) and at the end of Ramadan (R4).Compared to BR, fatigue estimated by POMS and Hooper questionnaires was higher at R4 in all groups (ES = 0.77-1.57, p 0.05). Hoff test distance increased to the same extent in SSG-S and SSG-L groups (+7.38-7.39%, ES = 1.49-1.93, p 0.001). Mean sRPE scores measured during Ramadan were higher after SSG-L (6.49 ± 0.38) than SSG-S (5.61 ± 0.14) sessions (+15.58%, ES = 2.79, p 0.001).SSG training can be implemented as an efficient intervention to avoid detraining and equally improve soccer-specific physical performance during Ramadan. Given the lower perceptual responses associated with shorter SSG sequences, this modality would be better tolerated during the fasting month, and therefore is recommended.
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- 2016
191. A multiobjective simulation optimization approach to define teams of workers in stochastic production systems
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Henri Pierreval, Sabeur Elkosantini, Achraf Ammar, Laboratoire d'Informatique, de Modélisation et d'Optimisation des Systèmes (LIMOS), Ecole Nationale Supérieure des Mines de St Etienne-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Ecole Nationale Supérieure des Mines de St Etienne (ENSM ST-ETIENNE)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), and DOREAU, Bastien
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[PHYS]Physics [physics] ,Engineering ,Mathematical optimization ,Operations research ,Job shop ,Heuristic (computer science) ,business.industry ,Evolutionary algorithm ,Sorting ,Context (language use) ,[INFO] Computer Science [cs] ,[PHYS] Physics [physics] ,8. Economic growth ,Genetic algorithm ,Redundancy (engineering) ,[INFO]Computer Science [cs] ,Unavailability ,business - Abstract
In this paper, we address team configuration problems in manufacturing systems, which consist in defining the number of workers to be assigned to a production system, as well as the skills that each worker must have in order to meet several performance measures. This problem is studied in a stochastic production context. A multi-objective evolutionary algorithm is connected to a simulation model to deal with this problem. Two objectives are considered. The first one is the minimization of the expected manpower cost associated to manufacturing team and the second one is the minimization of the expected mean flow time of jobs. Machines redundancy and workers multi-functionality are considered, when defining workers skills, to cope with possible random events such as workers unavailability and bottlenecks. Since the way workers are assigned to work centers strongly impact the results, a recent adaptive assignment heuristic is embedded in the simulation model and its parameters are also optimized. The proposed multi-objective simulation optimization approach is applied to design manufacturing teams, of a job shop production system, using the Nondominated Sorting Genetic Algorithm II (NSGA-II) connected to a simulation model developed using Arena. The set of non dominated solutions is found, so that an additional multi-criteria analysis can be performed.
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- 2015
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192. Temporal specificity of training: intra-day effects on biochemical responses and Olympic-Weightlifting performances
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Anitta Hoekelmann, Achraf Ammar, Johnny Padulo, Ahmed Hakim, Hamdi Chtourou, Mouna Turki, Khaled Trabelsi, and Kais El Abed
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Adult ,Male ,medicine.medical_specialty ,Evening ,Intra day ,Time Factors ,Weight Lifting ,Biochemical Phenomena ,Rest ,Physical Exertion ,Physical Therapy, Sports Therapy and Rehabilitation ,Athletic Performance ,Body Temperature ,Young Adult ,One-repetition maximum ,medicine ,Humans ,Orthopedics and Sports Medicine ,Muscle Strength ,Muscle, Skeletal ,Morning ,Rating of perceived exertion ,Hematologic Tests ,Physical Education and Training ,Oral temperature ,Muscle injury ,Physical therapy ,Perception ,Analysis of variance ,Psychology ,Biomarkers - Abstract
The aim of this study was to investigate the performance of an Olympic-Weightlifting session training at three times of the day on the performance related to biochemical responses. Nine weightlifters (21 ± 0.5 years) performed, in randomised order, on three Olympic-Weightlifting training (snatch, clean and jerk) sessions (08:00 a.m., 02:00 p. m., 06:00 p. m.). Blood samples were collected: before, 3 min and 48 h after each training session. Haematological parameters and markers of muscle injury were assessed. Resting oral temperature and rating of perceived exertion (RPE) were also assessed during each session. ANOVA showed that the performance was better (P0.001) at 02:00 p. m. with a less RPE (P0.01) compared to the morning and the evening sessions while there was higher (P0.05) oral temperature at 06:00 p. m. versus 08:00 a.m. and 02:00 p. m. Muscle damage changed immediately (without significant effect after 48 h) after the training sessions with lower values in the evening compared to the morning. In conclusion, the afternoon training is more effective than morning or evening sessions for weightlifters. Therefore, coaches and weightlifters should be advised to schedule their training session in the afternoon hour.
- Published
- 2014
193. Serious Game Based on Visual Interactive Simulation for Dynamic Workers Assignment
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Achraf Ammar, Henri Pierreval, and Sabeur Elkosentini
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Operations research ,Multimedia ,Computer science ,Event (computing) ,Production (economics) ,Scientific literature ,Serious game ,Heuristics ,Visual interactive simulation ,computer.software_genre ,computer ,Task (project management) ,Visualization - Abstract
Assigning workers to machines dynamically, so as to achieve production objectives, is known as a difficult problem which must be addressed in several manufacturing systems. In fact, production managers must determine when and where to assign workers, which is a very difficult task because of the complexity induced by the dynamic changes and the stochastic behavior of these systems. The current scientific literature is mainly oriented towards static assignments problems (only few dynamic heuristics are published). We propose a new approach whose aim is to help the managers in improving their knowledge about how to assign workers in real time. It is based on Serious Games built using Visual Interactive Simulation (discrete event). Our experiments show that an appropriate training using the proposed game can improve the users' ability to make good decisions about dynamic workers assignment and that human decisions can become more efficient than existing workers assignment rules found in the literature.
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- 2013
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194. Resolution of multi-skilled workers assignment problem using simulation optimization: A case study
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Sabeur Elkosantini, Achraf Ammar, and Henri Pierreval
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Mathematical optimization ,Job shop scheduling ,Nurse scheduling problem ,Computer science ,Assignment problem ,Generalized assignment problem ,Weapon target assignment problem ,Deadline-monotonic scheduling ,Tabu search ,Scheduling (computing) - Abstract
This paper addresses a worker assignment problem where multi-skilled workers perform a set of tasks independently and without walking and work sharing between workstations. A real case study is considered in this work. This problem is solved as a non-identical parallel machines scheduling problem with stochastic processing time where each machine represent one worker. A simulation optimization (SO) approach, using a robust tabu search (TS) algorithm that is coupled with a simulation model, is proposed to minimize the maximum completion time (makespan). The results is compared with this obtained by the using assignment method in the SETA Company.
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- 2012
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195. A reliability generalization meta-analysis of the internal consistency and test-retest reliability of the pre-sleep arousal scale (PSAS).
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Correia IL, Husain W, Gonçalves MT, Pires L, Trabelsi K, Achraf A, Pandi-Perumal SR, Nicassio PM, Jansson-Fröjmark M, Vitiello MV, Marques DR, and Jahrami H
- Abstract
Purpose: The Pre-Sleep Arousal Scale (PSAS) is a self-report tool for assessing cognitive and somatic arousal before sleep. While the English version is well-validated, research on translations is limited. This meta-analysis examines PSAS translations' internal consistency and reliability., Methods: We conducted a comprehensive literature search using multiple databases to identify studies that reported the reliability of the PSAS. We used a random-effects meta-analysis model to pool estimates of internal consistency and test-retest reliability and explored potential moderators using subgroup analyses and meta-regression. To ensure transparency, we registered the study protocol, utilized the PRISMA checklist, and made all study code and data available on the Open Science Framework., Results: Systematic review yielded a total 27 studies (reported in 25 publications) with 9354 participants employing eleven language versions of the PSAS. Meta-analysis showed good internal consistency for the total PSAS (0.88, 95%CI 0.86-0.90) as well as the cognitive (α = 0.89, 95%CI 0.88-0.90) and somatic (α = 0.80, 95%CI 0.77-0.83) subscales. The PSAS also displayed excellent test-retest reliability for the total scale (r = 0.87, 95%CI 0.84-0.90), cognitive subscale (α = 0.80, 95%CI 0.77-0.84) and somatic subscale (α = 0.70, 95%CI 0.67-0.74). Participant characteristics (age and sex) did not significantly affect results., Conclusions: This meta-analysis shows that the PSAS is a reliable tool for detecting pre-sleep arousal based on its high internal consistency and test-retest reliability. The PSAS is useful across languages but quality translation appears to be crucial. Recommendations are offered for future adaptations and clinical use., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)
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- 2024
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196. COVID-19, physical (in-)activity, and dementia prevention.
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Müller P, Achraf A, Zou L, Apfelbacher C, Erickson KI, and Müller NG
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Physical inactivity is one major modifiable risk factor for dementia (especially Alzheimer's disease). Due to contact restrictions and isolation measures in response to the current COVID-19 (coronavirus disease 2019) pandemic, physical inactivity levels have increased by up to 30%, which will likely have adverse consequences for primary and secondary dementia prevention. Therefore, new interdisciplinary prevention approaches (eg, outdoor exercise; app-based exercise with online partners) are urgently needed that account for the suspected long-term lifestyle changes that the current-and upcoming-pandemics are likely to entail (increased use of home office, social isolation, avoidance of fitness centers and club sports, and so on)., Competing Interests: The authors declare that there is no conflict of interest., (© 2020 The Authors. Alzheimer's & Dementia: Translational Research & Clinical Interventions published by Wiley Periodicals, Inc. on behalf of Alzheimer's Association.)
- Published
- 2020
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