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We conducted a meta-analysis of randomized controlled trials investigating the effects of aerobic exercise training (AET) lasting ≥ 4 weeks on hippocampal volume and cardiorespiratory fitness (CRF) in cognitively unimpaired, healthy older individuals. Random-effects robust variance estimation models were used to test differences between AET and controls, while meta-regressions tested associations between CRF and hippocampal volume changes. We included eight studies (N = 554) delivering fully supervised AET for 3 to 12 months (M = 7.8, SD = 4.5) with an average AET volume of 129.85 min/week (SD = 45.5) at moderate-to-vigorous intensity. There were no significant effects of AET on hippocampal volume (SMD = 0.10, 95% CI - 0.01 to 0.21, p = 0.073), but AET moderately improved CRF (SMD = 0.30, 95% CI 0.12 to 0.48, p = 0.005). Improvement in CRF was not associated with changes in hippocampal volume (b SE  = 0.05, SE = 0.51, p = 0.923). From the limited number of studies, AET does not seem to impact hippocampal volume in cognitively unimpaired, healthy older individuals. Notable methodological limitations across investigations might mask the lack of effects., (© 2023. The Author(s), under exclusive licence to American Aging Association.)

Interventional studies offer strong evidence for exercise's osteogenic impact on bone particularly during growth. With rising osteoporosis rates in older women, enhancing bone strength early in life is crucial. Thus, investigating the osteogenic effects of different types of physical activities in young females is crucial. Despite varied findings, only two systematic reviews tried to explore this topic without examining how different types of exercise may affect bone health in adolescent girls. The first aim of this systematic review was to assess the impact of exercise training on bone health parameters in adolescent girls, and the second aim was to investigate whether the type of exercise training can modulate this effect. A systematic literature search was conducted using common electronic databases from inception - January 2023. Seven studies (355 participants) were eligible for inclusion in this systematic review. Two studies dealt with resistance training, 3 studies applied plyometric training, 1 study used team sports, and 1 study used dancing. Results indicate that plyometric training increases lumbar spine bone mass in adolescent girls. Well-designed randomized controlled trials with a proper training period (> 12 weeks) are needed to advocate a specific type of training which has the highest osteogenic effect., Competing Interests: Declaration of Competing Interest There is no conflict of interest., (Copyright © 2023 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.)

Abstract: Zecchin, A, Puggina, EF, Hortobágyi, T, and Granacher, U. Association between foundation strength and weightlifting exercises in highly trained weightlifters: support for a general strength component. J Strength Cond Res 37(7): 1375-1381, 2023-In addition to specific weightlifting exercises (i.e., clean and jerk and snatch), foundation strength exercises (i.e., overhead press, front squat, and deadlift) constitute an integral part of the weightlifters' training regime. The unexamined concept behind this training plan is that foundation strength exercises are associated with clean and jerk and snatch performance, implying the existence of a general strength component. We thus determined the relationship between performance in foundation strength exercises (overhead press, front squat, and deadlift) and weightlifting exercises (clean and jerk and snatch) in weightlifters. Well-trained weightlifters ( N = 19, age: 26.8 ± 4.4 years; body mass index: 27.6 ± 2.3 kg·m -2 ; and training history: 4.6 ± 0.8 years) performed 1 repetition maximum tests (1RM) in foundation strength and weightlifting exercises, over 14 days, in a randomized order. We observed significant correlations in 1RM performance between the overhead press and snatch ( r = 0.69), front squat and snatch ( r = 0.73), overhead press and clean and jerk ( r = 0.67), and front squat and clean and jerk ( r = 0.72, all r values: p < 0.01). No significant correlations were found for 1RM performance between the snatch and deadlift or between the clean and jerk and deadlift ( r- range: 0.20-0.58; p > 0.05). Stepwise linear regression revealed that 1RM performance in the overhead press and front squat explained 62% of the variance in snatch 1RM performance ( F = 5.51; p < 0.04). Overhead press and front squat 1RM performance explained 59% of the variance in the clean and jerk 1RM performance ( F = 5.14; p < 0.04). Our results demonstrate the existence of a general strength component between selected foundation strength exercises and weightlifting performance. However, the use of the front squat and overhead press to increase 1RM performance in weightlifting exercises needs to be determined in future research using a different methodological approach (i.e., longitudinal protocols), given that the observed correlations do not necessarily imply causation., (Copyright © 2022 National Strength and Conditioning Association.)

Previous research has shown that children who were enrolled to school according to the legal key date (i.e., keyage children, between eight and nine years in third grade) exhibited a linear physical fitness development in the ninth year of life. In contrast, children who were enrolled with a delay (i.e., older-than-keyage children [OTK], between nine and ten years in third grade) exhibited a lower physical fitness compared to what would be expected for their age. In these studies, cross-sectional age differences within third grade and timing of school enrollment were confounded. The present study investigated the longitudinal development of keyage and OTK children from third to fifth grade. This design also afforded a comparison of the two groups at the same average chronological age, that is a dissociation of the effects of timing of school enrollment and age. We tested six physical fitness components: cardiorespiratory endurance, coordination, speed, power of lower and upper limbs, and static balance. 1502 children (i.e., 1206 keyage and 296 OTK children) from 35 schools were tested in third, fourth, and fifth grade. Except for cardiorespiratory endurance, both groups developed from third to fourth and from fourth to fifth grade and keyage children outperformed OTK children at the average ages of 9.5 or 10.5 years. For cardiorespiratory endurance, there was no significant gain from fourth to fifth grade and keyage and OTK children did not differ significantly at 10.5 years of age. One reason for a delayed school enrollment could be that a child is (or is perceived as) biologically younger than their chronological age at the school entry examination, implying a negative correlation between chronological and biological age for OTK children. Indeed, a simple reflection of chronological age brought the developmental rate of the chronologically youngest OTK children in line with the developmental rate observed for keyage children, but did not eliminate all differences. The mapping of chronological and biological age of OTK children and other possible reasons for lower physical fitness of OTK children remain a task for future research., (© 2023. The Author(s).)

Timing of initial school enrollment may vary considerably for various reasons such as early or delayed enrollment, skipped or repeated school classes. Accordingly, the age range within school grades includes older-(OTK) and younger-than-keyage (YTK) children. Hardly any information is available on the impact of timing of school enrollment on physical fitness. There is evidence from a related research topic showing large differences in academic performance between OTK and YTK children versus keyage children. Thus, the aim of this study was to compare physical fitness of OTK (N = 26,540) and YTK (N = 2586) children versus keyage children (N = 108,295) in a representative sample of German third graders. Physical fitness tests comprised cardiorespiratory endurance, coordination, speed, lower, and upper limbs muscle power. Predictions of physical fitness performance for YTK and OTK children were estimated using data from keyage children by taking age, sex, school, and assessment year into account. Data were annually recorded between 2011 and 2019. The difference between observed and predicted z-scores yielded a delta z-score that was used as a dependent variable in the linear mixed models. Findings indicate that OTK children showed poorer performance compared to keyage children, especially in coordination, and that YTK children outperformed keyage children, especially in coordination. Teachers should be aware that OTK children show poorer physical fitness performance compared to keyage children., (© 2022. The Author(s).)

Children's physical fitness development and related moderating effects of age and sex are well documented, especially boys' and girls' divergence during puberty. The situation might be different during prepuberty. As girls mature approximately two years earlier than boys, we tested a possible convergence of performance with five tests representing four components of physical fitness in a large sample of 108,295 eight-year old third-graders. Within this single prepubertal year of life and irrespective of the test, performance increased linearly with chronological age, and boys outperformed girls to a larger extent in tests requiring muscle mass for successful performance. Tests differed in the magnitude of age effects (gains), but there was no evidence for an interaction between age and sex. Moreover, "physical fitness" of schools correlated at r = 0.48 with their age effect which might imply that "fit schools" promote larger gains; expected secular trends from 2011 to 2019 were replicated., (© 2021. The Author(s).)

Background: Office workers near retirement tend to be sedentary and can be prone to mobility limitations and diseases. We examined the dose effects of exergaming volume and duration of detraining on motor and cognitive function in office workers at late midlife to reduce sedentariness and mobility limitations., Methods: In an assessor-blinded randomized trial, 160 workers aged 55-65 years performed physically active video games in a nonimmersive form of virtual reality (exergaming) in small, supervised groups for 1 h, 1×, 2×, or 3×/week for 8 weeks followed by detraining for 8 and 16 weeks. Exergaming comprises high-intensity, full-body sensorimotor coordination, balance, endurance, and strengthening exercises. The primary outcome was the 6-minute walk test (6MWT), and secondary outcomes were body mass, self-reported physical activity, sleep quality, Berg Balance Scale, Short Physical Performance Battery, fast gait speed, dynamic balance, heart rate recovery after step test, and 6 cognitive tests., Results: The 3 groups were not different in any of the outcomes at baseline (all p > 0.05). The outcomes were stable and had acceptable reliability (intraclass correlation coefficients ≥0.334) over an 8-week control period. Training produced an inverted U-shaped dose response of no (1×), most (2×), and medium (3×/week) effects of exergaming volume in most motor and selected cognitive outcomes. The distance walked in the 6MWT (primary outcome) increased most (94 m, 19%, p < 0.05), medium (57 m, 12%, p < 0.05), and least (4 m, 1%) after exergaming 2×, 3×, or 0× (control) (all different p < 0.05). The highest responders tended to retain the exercise effects over 8 weeks of detraining, independent of training volume. This maintenance effect was less consistent after 16 weeks of detraining., Conclusion: Less was more during training and lasted longer after detraining. A medium dose volume of exergaming produced the largest clinically meaningful improvements in mobility and selected cognitive tests in 60-year-old office workers with mild mobility limitations and intact cognition., (© 2021 The Author(s). Published by S. Karger AG, Basel.)

Many adults older than 60 yr experience mobility limitations. Although physical exercise improves older adults' mobility, differences in baseline mobility produce large variations in individual responses to interventions, and these responses could further vary by the type and dose of exercise. Here, we propose an exercise prescription model for older adults based on their current mobility status.

Background: There is evidence that physical exercise training (PET) conducted at the workplace is effective in improving physical fitness and thus health. However, there is no current systematic review available that provides high-level evidence regarding the effects of PET on physical fitness in the workforce., Objectives: To quantify sex-, age-, and occupation type-specific effects of PET on physical fitness and to characterize dose-response relationships of PET modalities that could maximize gains in physical fitness in the working population., Data Sources: A computerized systematic literature search was conducted in the databases PubMed and Cochrane Library (2000-2019) to identify articles related to PET in workers., Study Eligibility Criteria: Only randomized controlled trials with a passive control group were included if they investigated the effects of PET programs in workers and tested at least one fitness measure., Study Appraisal and Synthesis Methods: Weighted mean standardised mean differences (SMD wm ) were calculated using random effects models. A multivariate random effects meta-regression was computed to explain the influence of key training modalities (e.g., training frequency, session duration, intensity) on the effectiveness of PET on measures of physical fitness. Further, subgroup univariate analyses were computed for each training modality. Additionally, methodological quality of the included studies was rated with the help of the Physiotherapy Evidence Database (PEDro) Scale., Results: Overall, 3423 workers aged 30-56 years participated in 17 studies (19 articles) that were eligible for inclusion. Methodological quality of the included studies was moderate with a median PEDro score of 6. Our analyses revealed significant, small-sized effects of PET on cardiorespiratory fitness (CRF), muscular endurance, and muscle power (0.29 ≤ SMD wm  ≤ 0.48). Medium effects were found for CRF and muscular endurance in younger workers (≤ 45 years) (SMD wm  = 0.71) and white-collar workers (SMD wm  = 0.60), respectively. Multivariate random effects meta-regression for CRF revealed that none of the examined training modalities predicted the effects of PET on CRF (R 2  = 0). Independently computed subgroup analyses showed significant PET effects on CRF when conducted for 9-12 weeks (SMD wm  = 0.31) and for 17-20 weeks (SMD wm  = 0.74)., Conclusions: PET effects on physical fitness in healthy workers are moderated by age (CRF) and occupation type (muscular endurance). Further, independently computed subgroup analyses indicated that the training period of the PET programs may play an important role in improving CRF in workers.

There is growing evidence that eccentric strength training appears to have benefits over traditional strength training (i.e., strength training with combined concentric and eccentric muscle actions) from muscular, neuromuscular, tendinous, and metabolic perspectives. Eccentric muscle strength is particularly needed to decelerate and stabilize the body during the braking phase of a jump exercise or during rapid changes of direction (CoD) tasks. However, surprisingly little research has been conducted to elucidate the effects of eccentric strength training or strength training with accentuated eccentric muscle actions on CoD speed performance. In this current opinion article, we present findings from cross-sectional studies on the relationship between measures of eccentric muscle strength and CoD speed performance. In addition, we summarize the few available studies on the effects of strength training with accentuated eccentric muscle actions on CoD speed performance in athletic populations. Finally, we propose strength training with accentuated eccentric muscle actions as a promising element in strength and conditioning programs of sports with high CoD speed demands. Our findings from five cross-sectional studies revealed statistically significant moderate- to large-sized correlations (r = 0.45-0.89) between measures of eccentric muscle strength and CoD speed performance in athletic populations. The identified three intervention studies were of limited methodological quality and reported small- to large-sized effects (d = 0.46-1.31) of strength training with accentuated eccentric muscle actions on CoD speed performance in athletes. With reference to the available but preliminary literature and from a performance-related point of view, we recommend strength and conditioning coaches to include strength training with accentuated eccentric muscle actions in training routines of sports with high CoD speed demands (e.g., soccer, handball, basketball, hockey) to enhance sport-specific performance. Future comparative studies are needed to deepen our knowledge of the effects of strength training with accentuated eccentric muscle actions on CoD speed performance in athletes.

Background: Proficiency in fundamental movement skills (FMS) lays the foundation for being physically active and developing more complex motor skills. Improving these motor skills may provide enhanced opportunities for the development of a variety of perceptual, social, and cognitive skills., Objective: The objective of this systematic review and meta-analysis was to assess the effects of FMS interventions on actual FMS, targeting typically developing young children., Method: Searches in seven databases (CINAHL, Embase, MEDLINE, PsycINFO, PubMed, Scopus, Web of Science) up to August 2015 were completed. Trials with children (aged 2-6 years) in childcare or kindergarten settings that applied FMS-enhancing intervention programs of at least 4 weeks and meeting the inclusion criteria were included. Standardized data extraction forms were used. Risk of bias was assessed using a standard scoring scheme (Effective Public Health Practice Project-Quality Assessment Tool for Quantitative Studies [EPHPP]). We calculated effects on overall FMS, object control and locomotor subscales (OCS and LMS) by weighted standardized mean differences (SMD between ) using random-effects models. Certainty in training effects was evaluated using GRADE (Grading of Recommendations Assessment, Development, and Evaluation System)., Results: Thirty trials (15 randomized controlled trials and 15 controlled trials) involving 6126 preschoolers (aged 3.3-5.5 years) revealed significant differences among groups in favor of the intervention group (INT) with small-to-large effects on overall FMS (SMD between 0.46), OCS (SMD between 1.36), and LMS (SMD between 0.94). Our certainty in the treatment estimates based on GRADE is very low., Conclusions: Although there is relevant effectiveness of programs to improve FMS proficiency in healthy young children, they need to be interpreted with care as they are based on low-quality evidence and immediate post-intervention effects without long-term follow-up.

Background: The effects of balance training (BT) in older adults on proxies of postural control and mobility are well documented in the literature. However, evidence-based dose-response relationships in BT modalities (i.e., training period, training frequency, training volume) have not yet been established in healthy older adults., Objectives: The objectives of this systematic literature review and meta-analysis are to quantify BT intervention effects and to additionally characterize dose-response relationships of BT modalities (e.g., training period, training frequency) through the analysis of randomized controlled trials (RCTs) that could maximize improvements in balance performance in healthy community-dwelling older adults., Data Sources: A computerized systematic literature search was performed in the electronic databases PubMed and Web of Science from January 1985 up to January 2015 to capture all articles related to BT in healthy old community-dwelling adults., Study Eligibility Criteria: A systematic approach was used to evaluate the 345 articles identified for initial review. Only RCTs were included if they investigated BT in healthy community-dwelling adults aged ≥65 years and tested at least one behavioral balance performance outcome (e.g., center of pressure displacements during single-leg stance). In total, 23 studies met the inclusionary criteria for review., Study Appraisal and Synthesis Methods: Weighted mean standardized mean differences between subjects (SMDbs) of the intervention-induced adaptations in balance performance were calculated using a random-effects model and tested for an overall intervention effect relative to passive controls. The included studies were coded for the following criteria: training modalities (i.e., training period, training frequency, training volume) and balance outcomes [static/dynamic steady-state (i.e., maintaining a steady position during standing and walking), proactive balance (i.e., anticipation of a predicted perturbation), reactive balance (i.e., compensation of an unpredicted perturbation) as well as balance test batteries (i.e., combined testing of different balance components as for example the Berg Balance Scale)]. Heterogeneity between studies was assessed using I2 and Chi2-statistics. The methodological quality of each study was tested by means of the Physiotherapy Evidence Database (PEDro) Scale., Results: Weighted mean SMDbs showed that BT is an effective means to improve static steady-state (mean SMDbs = 0.51), dynamic steady-state (mean SMDbs = 0.44), proactive (mean SMDbs = 1.73), and reactive balance (mean SMDbs = 1.01) as well as the performance in balance test batteries (mean SMDbs = 1.52) in healthy older adults. Our analyses regarding dose-response relationships in BT revealed that a training period of 11-12 weeks (mean SMDbs= 1.26), a frequency of three training sessions per week (mean SMDbs= 1.20), a total number of 36-40 training sessions (mean SMDbs = 1.39), a duration of a single training session of 31-45 min (mean SMDbs = 1.19), and a total duration of 91-120 min of BT per week (mean SMDbs = 1.93) of the applied training modalities is most effective in improving overall balance performance. However, it has to be noted that effect sizes for the respective training modalities were computed independently (i.e., modality specific). Because of the small number of studies that reported detailed information on training volume (i.e., number of exercises per training session, number of sets and/or repetitions per exercise, duration of single-balance exercises) dose-response relationships were not computed for these parameters., Limitations: The present findings have to be interpreted with caution because we indirectly compared dose-response relationships across studies using SMDbs and not in a single controlled study as it is difficult to separate the impact of a single training modality (e.g., training frequency) from that of the others. Moreover, the quality of the included studies was rather limited with a mean PEDro score of 5 and the heterogeneity between studies was considerable (i.e., I2 = 76-92 %)., Conclusions: Our detailed analyses revealed that BT is an effective means to improve proxies of static/dynamic steady-state, proactive, and reactive balance as well as performance in balance test batteries in healthy older adults. Furthermore, we were able to establish effective BT modalities to improve balance performance in healthy older adults. Thus, practitioners and therapists are advised to consult the identified dose-response relationships of this systematic literature review and meta-analysis. However, further research of high methodologic quality is needed to determine (1) dose-response relationships of BT in terms of detailed information on training volume (e.g., number of exercises per training session) and (2) a feasible and effective method to regulate training intensity in BT.

Background: Habitual walking speed predicts many clinical conditions later in life, but it declines with age. However, which particular exercise intervention can minimize the age-related gait speed loss is unclear., Purpose: Our objective was to determine the effects of strength, power, coordination, and multimodal exercise training on healthy old adults' habitual and fast gait speed., Methods: We performed a computerized systematic literature search in PubMed and Web of Knowledge from January 1984 up to December 2014. Search terms included 'Resistance training', 'power training', 'coordination training', 'multimodal training', and 'gait speed (outcome term). Inclusion criteria were articles available in full text, publication period over past 30 years, human species, journal articles, clinical trials, randomized controlled trials, English as publication language, and subject age ≥65 years. The methodological quality of all eligible intervention studies was assessed using the Physiotherapy Evidence Database (PEDro) scale. We computed weighted average standardized mean differences of the intervention-induced adaptations in gait speed using a random-effects model and tested for overall and individual intervention effects relative to no-exercise controls., Results: A total of 42 studies (mean PEDro score of 5.0 ± 1.2) were included in the analyses (2495 healthy old adults; age 74.2 years [64.4-82.7]; body mass 69.9 ± 4.9 kg, height 1.64 ± 0.05 m, body mass index 26.4 ± 1.9 kg/m2, and gait speed 1.22 ± 0.18 m/s). The search identified only one power training study, therefore the subsequent analyses focused only on the effects of resistance, coordination, and multimodal training on gait speed. The three types of intervention improved gait speed in the three experimental groups combined (n = 1297) by 0.10 m/s (±0.12) or 8.4% (±9.7), with a large effect size (ES) of 0.84. Resistance (24 studies; n = 613; 0.11 m/s; 9.3%; ES: 0.84), coordination (eight studies, n = 198; 0.09 m/s; 7.6%; ES: 0.76), and multimodal training (19 studies; n = 486; 0.09 m/s; 8.4%, ES: 0.86) increased gait speed statistically and similarly., Conclusions: Commonly used exercise interventions can functionally and clinically increase habitual and fast gait speed and help slow the loss of gait speed or delay its onset.

Purpose: The purpose of this study was to investigate the effects of back extensor fatigue on performance measures and electromyographic (EMG) activity of leg and trunk muscles during jumping on stable and unstable surfaces., Methods: Before and after a modified Biering-Sorensen fatigue protocol for the back extensors, countermovement (CMJ) and lateral jumps (LJ) were performed on a force plate under stable and unstable (balance pad on the force plate) conditions. Performance measures for LJ (contact time) and CMJ height and leg and trunk muscles EMG activity were tested in 14 male experienced jumpers during 2 time intervals for CMJ (braking phase, push-off phase) and 5 intervals for LJ (-30 to 0, 0-30, 30-60, 60-90, and 90-120 ms) in non-fatigued and fatigued conditions., Results: A significant main effect of test (fatigue) (p = 0.007, f = 0.57) was observed for CMJ height. EMG analysis showed a significant fatigue-induced decrease in biceps femoris and gastrocnemius activity with CMJ (p = 0.008, f = 0.58 andp = 0.04, f = 0.422, respectively). LJ contact time was not affected by fatigue or surface interaction. EMG activity was significantly lower in the tibialis anterior with LJ following fatigue (p = 0.05, f = 0.405). A test x surface (p = 0.04, f = 0.438) interaction revealed that the non-fatigued unstable CMJ gastrocnemius EMG activity was lower than the non-fatigued stable condition during the onset-of-force phase., Conclusion: The findings revealed that fatiguing the trunk negatively impacts CMJ height and muscle activity during the performance of CMJs. However, skilled jumpers are not additionally affected by a moderately unstable surface as compared to a stable surface.

Introduction: The present study investigated associations between trunk muscle strength, jump performance, and lower limb kinematics during drop jumps on stable and unstable surfaces. Next to this behavioral approach, correlations were also computed on a neuromuscular level between trunk and leg muscle activity during the same test conditions., Methods: Twenty-nine healthy and physically active subjects (age 23 ± 3 years) were enrolled in this study. Peak isokinetic torque (PIT) of the trunk flexors and extensors was assessed separately on an isokinetic device. In addition, tests included drop jumps (DJ) on a force plate under stable and unstable (i.e., balance pad on top of the force plate) surfaces. Lower limb kinematics as well as electromyographic activity of selected trunk and leg muscles were analyzed., Results: Significant positive but small correlations (0.50 ≤ r ≤ 0.66, p < 0.05) were detected between trunk extensor PIT and athletic performance measures (i.e., DJ height, DJ performance index), irrespective of surface condition. Further, significant negative but small correlation coefficients were examined between trunk extensor PIT and knee valgus motion under stable and unstable surface conditions (-0.48 ≤ r ≤ -0.45, p < 0.05). In addition, significant positive but small correlations (0.45 ≤ r ≤ 0.68, p < 0.05) were found between trunk and leg muscle activity, irrespective of surface condition., Discussion: Behavioral and neuromuscular data from this study indicate that, irrespective of the surface condition (i.e., jumping on stable or unstable ground), the trunk plays a minor role for leg muscle performance/activity during DJ. This implies only limited effects of trunk muscle strengthening on jump performance in the stretch-shortening cycle.

Background: With increasing age neuromuscular deficits (e.g., sarcopenia) may result in impaired physical performance and an increased risk for falls. Prominent intrinsic fall-risk factors are age-related decreases in balance and strength / power performance as well as cognitive decline. Additional studies are needed to develop specifically tailored exercise programs for older adults that can easily be implemented into clinical practice. Thus, the objective of the present trial is to assess the effects of a fall prevention program that was developed by an interdisciplinary expert panel on measures of balance, strength / power, body composition, cognition, psychosocial well-being, and falls self-efficacy in healthy older adults. Additionally, the time-related effects of detraining are tested., Methods/design: Healthy old people (n = 54) between the age of 65 to 80 years will participate in this trial. The testing protocol comprises tests for the assessment of static / dynamic steady-state balance (i.e., Sharpened Romberg Test, instrumented gait analysis), proactive balance (i.e., Functional Reach Test; Timed Up and Go Test), reactive balance (i.e., perturbation test during bipedal stance; Push and Release Test), strength (i.e., hand grip strength test; Chair Stand Test), and power (i.e., Stair Climb Power Test; countermovement jump). Further, body composition will be analysed using a bioelectrical impedance analysis system. In addition, questionnaires for the assessment of psychosocial (i.e., World Health Organisation Quality of Life Assessment-Bref), cognitive (i.e., Mini Mental State Examination), and fall risk determinants (i.e., Fall Efficacy Scale - International) will be included in the study protocol. Participants will be randomized into two intervention groups or the control / waiting group. After baseline measures, participants in the intervention groups will conduct a 12-week balance and strength / power exercise intervention 3 times per week, with each training session lasting 30 min. (actual training time). One intervention group will complete an extensive supervised training program, while the other intervention group will complete a short version ('3 times 3') that is home-based and controlled by weekly phone calls. Post-tests will be conducted right after the intervention period. Additionally, detraining effects will be measured 12 weeks after program cessation. The control group / waiting group will not participate in any specific intervention during the experimental period, but will receive the extensive supervised program after the experimental period., Discussion: It is expected that particularly the supervised combination of balance and strength / power training will improve performance in variables of balance, strength / power, body composition, cognitive function, psychosocial well-being, and falls self-efficacy of older adults. In addition, information regarding fall risk assessment, dose-response-relations, detraining effects, and supervision of training will be provided. Further, training-induced health-relevant changes, such as improved performance in activities of daily living, cognitive function, and quality of life, as well as a reduced risk for falls may help to lower costs in the health care system. Finally, practitioners, therapists, and instructors will be provided with a scientifically evaluated feasible, safe, and easy-to-administer exercise program for fall prevention.

The objective was to investigate the effects of high-velocity strength training on isometric strength of the leg extensors and jump height in female and male adolescents. Twenty-eight students (13 boys, 15 girls) ages 16 to 17 years participated in this study and were assigned to either a strength training group or a control group. Strength training was conducted over 8 weeks (2 times per week). Pre- and post-training tests included the measurements of maximal isometric force and rate of force development of the leg extensors as well as countermovement jump height. Both girls (effect size = 1.37) and boys (effect size = 0.61) showed significant improvements in jump height. However, significant increases in maximal isometric force (effect size = 1.85) and rate of force development (effect size = 2.23) were found only in girls. In female and male adolescents, high-velocity strength training is an effective training regimen that produced improvements in countermovement jump height in both sexes but higher gains in maximal isometric force and rate of force development in girls.

Compared with resistance training, information concerning the progressive configuration of balance training (BT) is rare and lacks scientific validation. Therefore, a study was designed to determine participants' ability to perform balance exercises with increasing level of difficulty. The task required the participants (N = 20) to stand as stable as possible on a computerized balance platform. The experiment was performed on 3 testing days using different stance and sensory conditions. On each day, bipedal, step, tandem, and monopedal stands were performed 3 times while sensory conditions changed from firm ground, eyes opened (day 1) over foam ground, eyes opened (day 2) to firm ground, eyes closed (day 3). The results showed that total center of pressure displacements significantly increased when the use of sensory information (comparison between testing days: all p < 0.001) or when the base of support (comparison within testing days: all p < 0.001) was gradually reduced. Based on the observed pattern of increased postural sway across all testing conditions and the levels of trial variability, exercises were categorized into several stages of training. Findings indicate that balance performance decreased in response to an increased level of task difficulty introduced by narrowing the base of support and by limiting the use of sensory information. Practitioners can use the derived exercise ranking to select exercises for BT appropriate to the level of participants' balance ability and to implement progression in balance training.

Background: Both individual socio-cultural determinants such as selected parental characteristics (migrant background, low educational level and workload) as well as the regional environment are related to childhood overweight and physical activity (PA). The purpose of the study was to compare the impact of distinct socio-cultural determinants such as the regional environment and selected parental characteristics on adiposity, PA and motor skills in preschool children., Methods: Forty preschools (N = 542 children) of two culturally different urban regions (German and French speaking part of Switzerland) participated in the study (Ballabeina Study). Outcome measures included adiposity (BMI and skinfold thickness), objectively measured sedentary activities and PA (accelerometers) and agility performance (obstacle course). Parental characteristics (migrant status, educational level and workload) were assessed by questionnaire., Results: Children from the French speaking areas had higher adiposity, lower levels of total and of more intense PA, were more sedentary and less agile than children from the German speaking regions (percent differences for all outcome parameters except for BMI ≥10%; all p ≤ 0.04). Differences in skinfold thickness, sedentary activities and agility, but not in PA, were also found between children of Swiss and migrant parents, though they were ≤8% (p ≤ 0.02). While paternal workload had no effect, maternal workload and parental education resulted in differences in some PA measures and/or agility performance (percent differences in both: ≤9%, p ≤ 0.008), but not in adiposity or sedentary activities (p = NS). Regional differences in skinfold thickness, PA, sedentary activities and agility performance persisted after adjustment for parental socio-cultural characteristics, parental BMI and, where applicable, children's skinfolds (all p ≤ 0.01)., Conclusions: The regional environment, especially the broader social environment, plays a prominent role in determining adiposity, PA and motor skills of young children and should be implicated in the prevention of obesity and promotion of PA in children., Trial Registration: clinicaltrials.gov NCT00674544.

Background: The reactive strength index (RSI) is meaningfully associated with independent markers of athletic (e.g., linear sprint speed) and neuromuscular performance [e.g., stretch–shortening cycle (SSC)]. Plyometric jump training (PJT) is particularly suitable to improve the RSI due to exercises performed in the SSC. However, no literature review has attempted to meta-analyse the large number of studies regarding the potential effects of PJT on the RSI in healthy individuals across the lifespan. Objective: The aim of this systematic review with meta-analysis was to examine the effects of PJT on the RSI of healthy individuals across the lifespan compared with active/specific-active controls. Methods: Three electronic databases (PubMed, Scopus, Web of Science) were searched up to May 2022. According to the PICOS approach, the eligibility criteria were: (1) healthy participants, (2) PJT interventions of ≥ 3 weeks, (3) active (e.g., athletes involved in standard training) and specific-active (e.g., individuals using heavy resistance training) control group(s), (4) a measure of jump-based RSI pre-post training, and (5) controlled studies with multi-groups in randomised and non-randomised designs. The Physiotherapy Evidence Database (PEDro) scale was used to assess the risk of bias. The random-effects model was used to compute the meta-analyses, reporting Hedges' g effect sizes (ES) with 95% confidence intervals (95% CIs). Statistical significance was set at p ≤ 0.05. Subgroup analyses were performed (chronological age; PJT duration, frequency, number of sessions, total number of jumps; randomization). A meta-regression was conducted to verify if PJT frequency, duration, and total number of sessions predicted the effects of PJT on the RSI. Certainty or confidence in the body of evidence was assessed using Grading of Recommendations Assessment, Development, and Evaluation (GRADE). Potential adverse health effects derived from PJT were researched and reported. Results: Sixty-one articles were meta-analysed, with a median PEDro score of 6.0, a low risk of bias and good methodological quality, comprising 2576 participants with an age range of 8.1–73.1 years (males, ~ 78%; aged under 18 years, ~ 60%); 42 studies included participants with a sport background (e.g., soccer, runners). The PJT duration ranged from 4 to 96 weeks, with one to three weekly exercise sessions. The RSI testing protocols involved the use of contact mats (n = 42) and force platforms (n = 19). Most studies reported RSI as mm/ms (n = 25 studies) from drop jump analysis (n = 47 studies). In general, PJT groups improved RSI compared to controls: ES = 0.54, 95% CI 0.46–0.62, p < 0.001. Training-induced RSI changes were greater (p = 0.023) for adults [i.e., age ≥ 18 years (group mean)] compared with youth. PJT was more effective with a duration of > 7 weeks versus ≤ 7 weeks, > 14 total PJT sessions versus ≤ 14 sessions, and three weekly sessions versus < three sessions (p = 0.027–0.060). Similar RSI improvements were noted after ≤ 1080 versus > 1080 total jumps, and for non-randomised versus randomised studies. Heterogeneity (I2) was low (0.0–22.2%) in nine analyses and moderate in three analyses (29.1–58.1%). According to the meta-regression, none of the analysed training variables explained the effects of PJT on RSI (p = 0.714–0.984, R2 = 0.0). The certainty of the evidence was moderate for the main analysis, and low-to-moderate across the moderator analyses. Most studies did not report soreness, pain, injury or related adverse effects related to PJT. Conclusions: The effects of PJT on the RSI were greater compared with active/specific-active controls, including traditional sport-specific training as well as alternative training interventions (e.g., high-load slow-speed resistance training). This conclusion is derived from 61 articles with low risk of bias (good methodological quality), low heterogeneity, and moderate certainty of evidence, comprising 2576 participants. PJT-related improvements on RSI were greater for adults versus youths, after > 7 training weeks versus ≤ 7 weeks, with > 14 total PJT versus ≤ 14 sessions, and with three versus < three weekly sessions. [ABSTRACT FROM AUTHOR]

Oral pathologies can cause athletic underperformance. The aim of this study was to determine the effect of malocclusion on maximal aerobic capacity in young athletes with the same anthropometric data, diet, training mode, and intensity from the same athletics training center. Sub-elite track and field athletes (middle-distance runners) with malocclusion (experimental group (EG); n = 37; 21 girls; age: 15.1 ± 1.5 years) and without malocclusion (control group (CG); n = 13; 5 girls; age: 14.7 ± 1.9 years) volunteered to participate in this study. Participants received an oral diagnosis to examine malocclusion, which was defined as an overlapping of teeth that resulted in impaired contact between the teeth of the mandible and the teeth of the upper jaw. Maximal aerobic capacity was assessed using the VAMEVAL test (calculated MAS and estimated VO2max). The test consisted of baseline values that included the following parameters: maximum aerobic speed (MAS), maximal oxygen uptake (VO2max), heart rate frequency, systolic (SAP) and diastolic arterial pressure (DAP), blood lactate concentration (LBP), and post-exercise blood lactate assessment (LAP) after the performance of the VAMEVAL test. There were no statistically significant differences between the two study groups related to either anthropometric data (age: EG = 15.1 ± 1.5 vs. CC = 14.7 ± 1.9 years (p = 0.46); BMI: EG = 19.25 ± 1.9 vs. CC = 19.42 ± 1.7 kg/m2 (p = 0.76)) or for the following physical fitness parameters and biomarkers: MAS: EG = 15.5 (14.5–16.5) vs. CG = 15.5 (15–17) km/h (p = 0.47); VO2max: EG = 54.2 (52.5–58.6) vs. CG = 54.2 (53.4–59.5) mL/kg/min (p = 0.62) (IQR (Q1–Q3)); heart rate before the physical test: EG = 77.1 ± 9.9 vs. CG = 74.3 ± 14.0 bpm (p = 0.43); SAP: EG = 106.6 ± 13.4 vs. CG = 106.2 ± 14.8 mmHg (p = 0.91); DAP: EG = 66.7 ± 9.1 vs. CG = 63.9 ± 10.2 mmHg (p = 0.36); LBP: EG = 1.5 ± 0.4 vs. CG = 1.3 ± 0.4 mmol/L (p = 0.12); and LAP: EG = 4.5 ± 2.36 vs. CG = 4.06 ± 3.04 mmol/L (p = 0.60). Our study suggests that dental malocclusion does not impede maximal aerobic capacity and the athletic performance of young track and field athletes. [ABSTRACT FROM AUTHOR]

Complex contrast training (CCT) is an exercise modality that utilizes both high-load resistance activity and low-load plyometric activity in a set-by-set fashion within a single exercise session. Such a combination of exercises targets multiple aspects of the force–velocity curve and may thus lead to improvement of various components of physical fitness. However, no previous study has attempted to compare the effects of load-equated two vs. three CCT sessions per week on measures of physical fitness. Forty-five male participants aged 21.4 ± 2.0 years were randomly assigned to either two weekly CCT sessions (CCT-2; n = 15), three weekly CCT sessions (CCT-3; n = 15), or an active control group (CG; n = 15). Selected measures of physical fitness were assessed pre- and post-six weeks of training. The tests included the assessment of 15 and 30 m linear sprint speeds, upper (medicine ball throw) and lower limb muscle power (standing long jump and countermovement jump with arm thrust), muscle strength (isokinetic peak knee extensor/flexor torque), and change-of-direction speed (modified agility T-test (MAT)). Significant group–time interactions were observed for all dependent variables (all p < 0.001, ɳp2 = 0.51–0.78) using ANOVA. Post hoc tests indicated significant performance improvements for the CCT-2 and CCT3 groups for all dependent variables (Hedge's g = 0.28–3.26, %Δ = 2.4–16.7), including the 15 and 30 m linear sprint speeds (p < 0.001), medicine ball throw (p < 0.001), standing long jump (p < 0.001), countermovement jump with arm thrust (p < 0.001), right leg knee extensor (p < 0.001) and flexor peak torque (p < 0.001), left leg knee extensor (p < 0.001) and flexor peak torque (p < 0.001), and change-of-direction speed (p < 0.001). The CCT-3 group showed greater improvements in MAT compared to the CCT-2 group (g = 3.26 vs. 0.70, p < 0.001). In conclusion, compared to active controls, the load-equated CCT-2 and CCT-3 programs provided similar effects on measures of physical fitness in active adult males. However, an athlete's goal is to improve their MAT score, the CCT-3 program may elicit greater improvements compared with the CCT-2 program. [ABSTRACT FROM AUTHOR]

Purpose: To examine the effects of drop height on drop-jump (DJ) performance and on associations between DJ and horizontal-jump/sprint performances in adolescent athletes. Methods: Male (n = 119, 2.5 [0.6] y post-peak-height velocity) and female (n = 120, 2.5 [0.5] y post-peak-height velocity) adolescent handball players (national level) performed DJs in randomized order using 3 drop heights (20, 35, and 50 cm). DJ performance (jump height, reactive strength index [RSI]) was analyzed using the Optojump Next system. In addition, correlations were computed between DJ height and RSI with standing-long-jump and 20-m linear-sprint performances. Results: Statistical analyses revealed medium-size main effects of drop height for DJ height and RSI (P <.001, 0.63 ≤ d ≤ 0.71). Post hoc tests indicated larger DJ heights from 20 to 35 and 35 to 50 cm (P ≤.031, 0.33 ≤ d ≤ 0.71) and better RSI from 20- to 35-cm drop height (P <.001, d = 0.77). No significant difference was found for RSI between 35- and 50-cm drop height. Irrespective of drop height, associations of DJ height and RSI were small with 5-m-split time (−.27 ≤ r ≤.05), medium with 10-m-split time (−.44 ≤ r ≤.14), and medium to large with 20-m sprint time and standing-long-jump distance (−.57 ≤ r ≤.22). Conclusions: The present findings indicate that, irrespective of sex, 35-cm drop heights are best suited to induce rapid and powerful DJ performance (ie, RSI) during reactive strength training in elite adolescent handball players. Moreover, training-related gains in DJ performance may at least partly translate to gains in horizontal jump and longer sprint distances (ie, ≥20-m) and/or vice versa in male and female elite adolescent athletes, irrespective of drop height. [ABSTRACT FROM AUTHOR]

The aim of this review was to describe and summarize the scientific literature on programming parameters related to jump or plyometric training in male and female soccer players of different ages and fitness levels. A literature search was conducted in the electronic databases PubMed, Web of Science and Scopus using keywords related to the main topic of this study (e.g., "ballistic" and "plyometric"). According to the PICOS framework, the population for the review was restricted to soccer players, involved in jump or plyometric training. Among 7556 identified studies, 90 were eligible for inclusion. Only 12 studies were found for females. Most studies (n = 52) were conducted with youth male players. Moreover, only 35 studies determined the effectiveness of a given jump training programming factor. Based on the limited available research, it seems that a dose of 7 weeks (1–2 sessions per week), with ~80 jumps (specific of combined types) per session, using near-maximal or maximal intensity, with adequate recovery between repetitions (<15 s), sets (≥30 s) and sessions (≥24–48 h), using progressive overload and taper strategies, using appropriate surfaces (e.g., grass), and applied in a well-rested state, when combined with other training methods, would increase the outcome of effective and safe plyometric-jump training interventions aimed at improving soccer players physical fitness. In conclusion, jump training is an effective and easy-to-administer training approach for youth, adult, male and female soccer players. However, optimal programming for plyometric-jump training in soccer is yet to be determined in future research. [ABSTRACT FROM AUTHOR]

Background: The fatigue of a muscle or muscle group can produce global responses to a variety of systems (i.e., cardiovascular, endocrine, and others). There are also reported strength and endurance impairments of non-exercised muscles following the fatigue of another muscle; however, the literature is inconsistent. Objective: To examine whether non-local muscle fatigue (NLMF) occurs following the performance of a fatiguing bout of exercise of a different muscle(s). Design: Systematic review and meta-analysis. Search and Inclusion: A systematic literature search using a Boolean search strategy was conducted with PubMed, SPORTDiscus, Web of Science, and Google Scholar in April 2020, and was supplemented with additional 'snowballing' searches up to September 2020. To be included in our analysis, studies had to include at least one intentional performance measure (i.e., strength, endurance, or power), which if reduced could be considered evidence of muscle fatigue, and also had to include the implementation of a fatiguing protocol to a location (i.e., limb or limbs) that differed to those for which performance was measured. We excluded studies that measured only mechanistic variables such as electromyographic activity, or spinal/supraspinal excitability. After search and screening, 52 studies were eligible for inclusion including 57 groups of participants (median sample = 11) and a total of 303 participants. Results: The main multilevel meta-analysis model including all effects sizes (278 across 50 clusters [median = 4, range = 1 to 18 effects per cluster) revealed a trivial point estimate with high precision for the interval estimate [− 0.02 (95% CIs = − 0.14 to 0.09)], yet with substantial heterogeneity (Q(277) = 642.3, p < 0.01), I2 = 67.4%). Subgroup and meta-regression analyses showed that NLMF effects were not moderated by study design (between vs. within-participant), homologous vs. heterologous effects, upper or lower body effects, participant training status, sex, age, the time of post-fatigue protocol measurement, or the severity of the fatigue protocol. However, there did appear to be an effect of type of outcome measure where both strength [0.11 (95% CIs = 0.01–0.21)] and power outcomes had trivial effects [− 0.01 (95% CIs = − 0.24 to 0.22)], whereas endurance outcomes showed moderate albeit imprecise effects [− 0.54 (95% CIs = − 0.95 to − 0.14)]. Conclusions: Overall, the findings do not support the existence of a general NLMF effect; however, when examining specific types of performance outcomes, there may be an effect specifically upon endurance-based outcomes (i.e., time to task failure). However, there are relatively fewer studies that have examined endurance effects or mechanisms explaining this possible effect, in addition to fewer studies including women or younger and older participants, and considering causal effects of prior training history through the use of longitudinal intervention study designs. Thus, it seems pertinent that future research on NLMF effects should be redirected towards these still relatively unexplored areas. [ABSTRACT FROM AUTHOR]

We aimed to examine the effects of plyometric jump training (PJT) on measures of physical fitness in amateur and professional volleyball players. A systematic electronic literature search was carried out in the databases PubMed, MEDLINE, Web of Science, and SCOPUS. Controlled studies including pre-to-post intervention tests of physical fitness and involving healthy volleyball players regardless of age and sex were considered. A random-effects model was used to calculate effect sizes (ES) between intervention and control groups. Moderator analyses considered programme duration, training frequency, total number of training sessions and jumps, participants' sex, age, and expertise level. The Physiotherapy Evidence Database scale was used to assess the methodological quality of the included studies. Eighteen moderate-to-high quality (median of 5 PEDro points) studies were eligible, comprising a total of 746 athletes. None of the included studies reported injuries related to the PJT intervention. The main findings showed small-to-moderate effects (p < 0.05) of PJT on linear sprint speed (ES = 0.70), squat jump (ES = 0.56), countermovement jump (CMJ) (ES = 0.80), CMJ with arm swing (ES = 0.63), drop jump (ES = 0.81), and spike jump height (ES = 0.84). Sub-analyses of moderator factors included 48 data sets. Only age had a significant effect on CMJ performance. Participants aged ≥16 years achieved greater improvements in CMJ performance compared to <16 years old (ES = 1.28 and 0.38, respectively; p = 0.022). No significant differences (p = 0.422) were identified between amateur (ES = 0.62) and professional volleyball players (ES = 1.01). In conclusion, PJT seems safe and is effective in improving measures of physical fitness in amateur and professional volleyball players, considering studies performed in both male and female. [ABSTRACT FROM AUTHOR]

Background: Both bilateral (BLE) and unilateral resistance exercise (ULE) methods can confer benefit to an athlete, but it remains to be established which has a greater effect on movement speed. Objectives: To evaluate the effects of BLE and ULE on horizontal movement performance. Data Sources: Google Scholar, CrossRef, and PubMed. Study Eligibility Criteria: To qualify for inclusion in the meta-analysis, studies must have included a resistance training intervention that compared the effects of BLE and ULE on a measure of movement speed such as sprinting in healthy study participants. Study Appraisal and Synthesis Methods: We used the inverse-variance random-effects model for meta-analyses. Effect sizes (standardised mean difference), calculated from measures of horizontally orientated performance, were represented by the standardised mean difference and presented alongside 95% confidence intervals (CI). Results: Though both modalities were effective (BLE = 0.60 [95% CI 0.34, 0.87], Z = 4.44 [p < 0.01]; ULE = 0.57 [95% CI 0.24, 0.89], Z = 3.44 [p = 0.0006]), there was no difference between the effect of BLE and ULE on movement speed (0.17 [95% CI − 0.15, 0.50], Z = 1.03 [p = 0.30]). For BLE, combined strength and plyometric training had the largest effect size (0.88 [95% CI 0.40, 1.36]]) followed by plyometric training (0.55 [95% CI 0.09, 1.01]), with the lowest effect in strength training (0.42 [95% CI − 0.02, 0.86]). For ULE, the largest effect size for training type was in plyometric training (0.78 [95% CI 0.33, 1.24]) closely followed by combined (0.63 [95% CI 0.03, 1.24]) with strength (0.29 [95% CI − 0.42, 1.01]) having a substantially lower effect size. Conclusions: Both BLE and ULE are effective in enhancing horizontal movement performance. However, contrary to popular opinion, supported by the concept of training specificity, ULE was no more effective at achieving this than BLE. [ABSTRACT FROM AUTHOR]

Objective: We investigated the effects of combined balance and strength training on measures of balance and muscle strength in older women with a history of falls. Methods: Twenty-seven older women aged 70.4 ± 4.1 years (age range: 65 to 75 years) were randomly allocated to either an intervention (IG, n = 12) or an active control (CG, n = 15) group. The IG completed 8 weeks combined balance and strength training program with three sessions per week including visual biofeedback using force plates. The CG received physical therapy and gait training at a rehabilitation center. Training volumes were similar between the groups. Pre and post training, tests were applied for the assessment of muscle strength (weight-bearing squat [WBS] by measuring the percentage of body mass borne by each leg at different knee flexions [0°, 30°, 60°, and 90°], sit-to-stand test [STS]), and balance. Balance tests used the modified clinical test of sensory interaction (mCTSIB) with eyes closed (EC) and opened (EO), on stable (firm) and unstable (foam) surfaces as well as spatial parameters of gait such as step width and length (cm) and walking speed (cm/s). Results: Significant group × time interactions were found for different degrees of knee flexion during WBS (0.0001 < p < 0.013, 0.441 < d < 0.762). Post hoc tests revealed significant pre-to-post improvements for both legs and for all degrees of flexion (0.0001 < p < 0.002, 0.697 < d < 1.875) for IG compared to CG. Significant group × time interactions were found for firm EO, foam EO, firm EC, and foam EC (0.006 < p < 0.029; 0.302 < d < 0.518). Post hoc tests showed significant pre-to-post improvements for both legs and for all degrees of oscillations (0.0001 < p < 0.004, 0.753 < d < 2.097) for IG compared to CG. This study indicates that combined balance and strength training improved percentage distribution of body weight between legs at different conditions of knee flexion (0°, 30°, 60°, and 90°) and also decreased the sway oscillation on a firm surface with eyes closed, and on foam surface (with eyes opened or closed) in the IG. Conclusion: The higher positive effects of training seen in standing balance tests, compared with dynamic tests, suggests that balance training exercises including lateral, forward, and backward exercises improved static balance to a greater extent in older women. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the effects of a 8-week plyometric jump training (PJT) performed on different surfaces (grass, land-dirt, sand, wood, gym mat, and tartan-track) vs. a single-surface PJT (grass) on components of physical fitness (muscle power, speed, and change-of-direction speed [CODS] tasks) and sport-specific performance (i.e., maximal kicking velocity [MKV]) in male soccer players aged 11-14 years. Athletes were randomly assigned to a combined surfaces PJT (PJTc, n = 8), a single-surface PJT (PJTs, n = 8), or an active control (CON, n = 7). Although the PJT group trained on grass, the PJTc trained on 6 different surfaces and equally distributed the total jump volume according to the surface. Pre-post tests were conducted on grass. Significant main effects of time were observed for the countermovement jump, the standing-long-jump, the 20-cm drop jump, 30-m sprint time, CODS, and MKV (all p < 0.001; d = 0.53-0.87). Group x time interactions were identified for all jump tests, MKV, 30-m sprint time, and CODS (all p < 0.001; d = 0.58-0.71) in favor of PJTc. No significant pre-post changes were observed in the CON (all p > 0.05; d = 0.07-0.1). In conclusion, PJT is effective in improving physical fitness in young soccer players when conducted in combination with regular soccer training. Although general fitness testing and PJTs were performed on grass, larger physical fitness improvements were found after PJTc. Thus, PJTc is recommended, as it provides a better overload stimulus compared with more conventional training overload (e.g., increase in training volume or intensity). Future studies still have to address the underlying physiological adaptations after PJTc. [ABSTRACT FROM AUTHOR]

The aim of this scoping review was a) to update a previous review on the main methodological characteristics and shortcomings in the plyometric jump training (PJT) literature, and b) to recommend, in light of the identified methodological gaps, future research perspectives. We searched four electronic databases. From 6128 potentially relevant articles, 420 were considered eligible for inclusion. As an update of a previous review, this represents an increase of ~200 articles, illustrating that this field of research is growing fast. However, the relative "quality" or shortcomings were similar when compared to the preceding scoping review. In the current article, the main identified shortcomings were an insufficient number of studies conducted with females, individual sports, and high‐level athletes (~22%, ~7%, and ~14% of overall studies, respectively); insufficient description of training prescription (~54% of studies); and studies missing an active/passive control group and a randomized group allocation process (~37% and ~24% of overall studies, respectively). Furthermore, PJT was often combined with other training methods and added to the participants' regular training routines (~50% and ~35% of overall studies, respectively). The main outcomes of this scoping review urge researchers to conduct PJT studies of high methodological quality (eg, randomized controlled trials) to get trustworthy evidence‐based knowledge. In addition, owing to the limited research conducted with females, individual sports, and high‐level athletes, more studies are needed to substantiate the available findings. Finally, the identification of cohort‐specific PJT dose‐response relations which elicit optimal training effects still needs to be identified, particularly in the long term. [ABSTRACT FROM AUTHOR]

The purpose of this systematic review with meta-analysis was to examine the effects of strength training (ST) on selected components of physical fitness (e.g., lower/upper limb maximal strength, muscular endurance, jump performance, cardiorespiratory endurance) and sport-specific performance in rowers. Only studies with an active control group were included if they examined the effects of ST on at least one proxy of physical fitness and/or sport-specific performance in rowers. Weighted and averaged standardized mean differences (SMD) were calculated using random-effects models. Subgroup analyses were computed to identify effects of ST type or expertise level on sport-specific performance. Our analyses revealed significant small effects of ST on lower limb maximal strength (SMD = 0.42, p = 0.05) and on sport-specific performance (SMD = 0.32, p = 0.05). Non-significant effects were found for upper limb maximal strength, upper/lower limb muscular endurance, jump performance, and cardiorespiratory endurance. Subgroup analyses for ST type and expertise level showed non-significant differences between the respective subgroups of rowers (p ≥ 0.32). Our systematic review with meta-analysis indicated that ST is an effective means for improving lower limb maximal strength and sport-specific performance in rowers. However, ST-induced effects are neither modulated by ST type nor rowers' expertise level. CON: control group; ICC: intraclass correlation coefficient; CRE: cardiorespiratory endurance; F: female; IG: intervention group; INT: intervention group; M: male; Sets: number of sets per exercise; SMD: standardized mean differences; SMDwm: weighted mean SMD; ST: strength training; RCT: randomized controlled trial; Reps: repetitions; RM: repetition maximum; TF: training frequency (times per week); TI: training intensity (eg., % of 1 repetition maximum); TP: training periods (weeks) [ABSTRACT FROM AUTHOR]

Background: Jump training (JT) can be used to enhance the ability of skeletal muscle to exert maximal force in as short a time as possible. Despite its usefulness as a method of performance enhancement in athletes, only a small number of studies have investigated its effects on muscle power in older adults.Objectives: The aims of this meta-analysis were to measure the effect of JT on muscular power in older adults (≥ 50 years), and to establish appropriate programming guidelines for this population.Data Sources: The data sources utilised were Google Scholar, PubMed, and Microsoft Academic.Study Eligibility Criteria: Studies were eligible for inclusion if they comprised JT interventions in healthy adults (≥ 50 years) who were free of any medical condition that could impair movement.Study Appraisal and Synthesis Methods: The inverse variance random-effects model for meta-analyses was used because it allocates a proportionate weight to trials based on the size of their individual standard errors and facilitates analysis while accounting for heterogeneity across studies. Effect sizes (ESs), calculated from a measure of muscular power, were represented by the standardised mean difference and were presented alongside 95% confidence intervals (CIs).Results: Thirteen training groups across nine studies were included in this meta-analysis. The magnitude of the main effect was ‘moderate’ (0.66, 95% CI 0.33, 0.98). ESs were larger in non-obese participants (body mass index [BMI] < 30 vs. ≥ 30 kg/m2; 1.03 [95% CI 0.34, 1.73] vs. 0.53 [95% CI − 0.03, 1.09]). Among the studies included in this review, just one reported an acute injury, which did not result in the participant ceasing their involvement. JT was more effective in programmes with more than one exercise (range 1-4 exercises; ES = 0.74 [95% CI − 0.49, 1.96] vs. 0.53 [95% CI 0.29, 0.78]), more than two sets per exercise (range 1-4 sets; ES = 0.91 [95% CI 0.04, 1.77] vs. 0.68 [95% CI 0.15, 1.21]), more than three jumps per set (range 1-14 jumps; ES = 1.02 [95% CI 0.16, 1.87] vs. 0.53 [95% CI − 0.03, 1.09]) and more than 25 jumps per session (range 6-200 jumps; ES = 0.88 [95% CI 0.05, 1.70] vs. 0.49 [95% CI 0.14, 0.83]).Conclusions: JT is safe and effective in older adults. Practitioners should construct varied JT programmes that include more than one exercise and comprise more than two sets per exercise, more than three jumps per set, and 60 s of recovery between sets. An upper limit of three sets per exercise and ten jumps per set is recommended. Up to three training sessions per week can be performed. [ABSTRACT FROM AUTHOR]

Recently, there has been a proliferation of published articles on the effect of plyometric jump training, including several review articles and meta-analyses. However, these types of research articles are generally of narrow scope. Furthermore, methodological limitations among studies (e.g., a lack of active/passive control groups) prevent the generalization of results, and these factors need to be addressed by researchers. On that basis, the aims of this scoping review were to (1) characterize the main elements of plyometric jump training studies (e.g., training protocols) and (2) provide future directions for research. From 648 potentially relevant articles, 242 were eligible for inclusion in this review. The main issues identified related to an insufficient number of studies conducted in females, youths, and individual sports (~ 24.0, ~ 37.0, and ~ 12.0% of overall studies, respectively); insufficient reporting of effect size values and training prescription (~ 34.0 and ~ 55.0% of overall studies, respectively); and studies missing an active/passive control group and randomization (~ 40.0 and ~ 20.0% of overall studies, respectively). Furthermore, plyometric jump training was often combined with other training methods and added to participants’ daily training routines (~ 47.0 and ~ 39.0% of overall studies, respectively), thus distorting conclusions on its independent effects. Additionally, most studies lasted no longer than 7 weeks. In future, researchers are advised to conduct plyometric training studies of high methodological quality (e.g., randomized controlled trials). More research is needed in females, youth, and individual sports. Finally, the identification of specific dose-response relationships following plyometric training is needed to specifically tailor intervention programs, particularly in the long term. [ABSTRACT FROM AUTHOR]

Introduction/Purpose: Aging modifies neuromuscular activation of agonist and antagonist muscles during walking. Power training can evoke adaptations in neuromuscular activation that underlie gains in muscle strength and power but it is unknown if these adaptations transfer to dynamic tasks such as walking. We examined the effects of lower extremity power training on neuromuscular activation during level gait in old adults. Methods: Twelve community dwelling old adults (age ≥ 65 years) completed a 10-week lower extremity power-training program and thirteen old adults completed a 10-week control period. Before and after the interventions, we measured maximal isometric muscle strength and electromyographic (EMG) activation of the right knee flexor, knee extensor, and plantarflexor muscles on a dynamometer and we measured EMG amplitudes, activation onsets and offsets, and activation duration of the knee flexors, knee extensors, and plantarflexors during gait at habitual, fast, and standardized (1.25±0.6m·s-1) speeds. Results: Power training-induced increases in EMG amplitude (~41%; 0.47≤d≤1.47; P≤0.05) explained 33% (P=0.049) of increases in isometric muscle strength (~43%; 0.34≤d≤0.80; P≤0.05). Power training-induced gains in plantarflexor activation during push-off (+11%; d=0.38; p=0.045) explained 57% (P=0.004) of the gains in fast gait velocity (+4%; d=0.31; P=0.059). Furthermore, power training increased knee extensor activation (~18%; 0.26≤d≤0.29; P≤0.05) and knee extensor coactivation during the main knee flexor burst (~24%, 0.26≤d≤0.44; P≤0.05) at habitual and fast speed but these adaptations did not correlate with changes in gait velocity Conclusion: Power training increased neuromuscular activation during isometric contractions and level gait in old adults. The power training-induced neuromuscular adaptations were associated with increases in isometric muscle strength and partly with increases in fast gait velocity. [ABSTRACT FROM AUTHOR]

Background: Balance and resistance training can improve healthy older adults' balance and muscle strength. Delivering such exercise programs at home without supervision may facilitate participation for older adults because they do not have to leave their homes. To date, no systematic literature analysis has been conducted to determine if supervision affects the effectiveness of these programs to improve healthy older adults' balance and muscle strength/power. Objectives: The objective of this systematic review and meta-analysis was to quantify the effectiveness of supervised vs. unsupervised balance and/or resistance training programs on measures of balance and muscle strength/power in healthy older adults. In addition, the impact of supervision on training-induced adaptive processes was evaluated in the form of dose-response relationships by analyzing randomized controlled trials that compared supervised with unsupervised trials. Data Sources: A computerized systematic literature search was performed in the electronic databases PubMed, Web of Science, and SportDiscus to detect articles examining the role of supervision in balance and/or resistance training in older adults. Study Eligibility Criteria: The initially identified 6041 articles were systematically screened. Studies were included if they examined balance and/or resistance training in adults aged ≥65 years with no relevant diseases and registered at least one behavioral balance (e.g., time during single leg stance) and/or muscle strength/power outcome (e.g., time for 5-Times-Chair-Rise-Test). Finally, 11 studies were eligible for inclusion in this meta-analysis. Study Appraisal: Weighted mean standardized mean differences between subjects (SMD) of supervised vs. unsupervised balance/resistance training studies were calculated. The included studies were coded for the following variables: number of participants, sex, age, number and type of interventions, type of balance/strength tests, and change (%) from pre- to post-intervention values. Additionally, we coded training according to the following modalities: period, frequency, volume, modalities of supervision (i.e., number of supervised/unsupervised sessions within the supervised or unsupervised training groups, respectively). Heterogeneity was computed using I and χ statistics. The methodological quality of the included studies was evaluated using the Physiotherapy Evidence Database scale. Results: Our analyses revealed that in older adults, supervised balance/resistance training was superior compared with unsupervised balance/resistance training in improving measures of static steady-state balance (mean SMD = 0.28, p = 0.39), dynamic steady-state balance (mean SMD = 0.35, p = 0.02), proactive balance (mean SMD = 0.24, p = 0.05), balance test batteries (mean SMD = 0.53, p = 0.02), and measures of muscle strength/power (mean SMD = 0.51, p = 0.04). Regarding the examined dose-response relationships, our analyses showed that a number of 10-29 additional supervised sessions in the supervised training groups compared with the unsupervised training groups resulted in the largest effects for static steady-state balance (mean SMD = 0.35), dynamic steady-state balance (mean SMD = 0.37), and muscle strength/power (mean SMD = 1.12). Further, ≥30 additional supervised sessions in the supervised training groups were needed to produce the largest effects on proactive balance (mean SMD = 0.30) and balance test batteries (mean SMD = 0.77). Effects in favor of supervised programs were larger for studies that did not include any supervised sessions in their unsupervised programs (mean SMD: 0.28-1.24) compared with studies that implemented a few supervised sessions in their unsupervised programs (e.g., three supervised sessions throughout the entire intervention program; SMD: −0.06 to 0.41). Limitations: The present findings have to be interpreted with caution because of the low number of eligible studies and the moderate methodological quality of the included studies, which is indicated by a median Physiotherapy Evidence Database scale score of 5. Furthermore, we indirectly compared dose-response relationships across studies and not from single controlled studies. Conclusions: Our analyses suggest that supervised balance and/or resistance training improved measures of balance and muscle strength/power to a greater extent than unsupervised programs in older adults. Owing to the small number of available studies, we were unable to establish a clear dose-response relationship with regard to the impact of supervision. However, the positive effects of supervised training are particularly prominent when compared with completely unsupervised training programs. It is therefore recommended to include supervised sessions (i.e., two out of three sessions/week) in balance/resistance training programs to effectively improve balance and muscle strength/power in older adults. [ABSTRACT FROM AUTHOR]