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Background A mechanical ankle–foot prosthesis (Talaris Demonstrator) was developed to improve prosthetic gait in people with a lower-limb amputation. This study aims to evaluate the Talaris Demonstrator (TD) during level walking by mapping coordination patterns based on the sagittal continuous relative phase (CRP). Methods Individuals with a unilateral transtibial amputation, transfemoral amputation and able-bodied individuals completed 6 minutes of treadmill walking in consecutive blocks of 2 minutes at self-selected (SS) speed, 75% SS speed and 125% SS speed. Lower extremity kinematics were captured and hip–knee and knee–ankle CRPs were calculated. Statistical non-parametric mapping was applied and statistical significance was set at 0.05. Results The hip–knee CRP at 75% SS walking speed with the TD was larger in the amputated limb of participants with a transfemoral amputation compared to able-bodied individuals at the beginning and end of the gait cycle (p = 0.009). In people with a transtibial amputation, the knee–ankle CRP at SS and 125% SS walking speeds with the TD were smaller in the amputated limb at the beginning of the gait cycle compared to able-bodied individuals (p = 0.014 and p = 0.014, respectively). Additionally, no significant differences were found between both prostheses. However, visual interpretation indicates a potential advantage of the TD over the individual's current prosthesis. Conclusion This study provides lower-limb coordination patterns in people with a lower-limb amputation and reveals a possible beneficial effect of the TD over the individuals’ current prosthesis. Future research should include a well-sampled investigation of the adaptation process combined with the prolonged effects of the TD.

OBJECTIVE: Dietary protein and physical activity interventions are increasingly implemented during hemodialysis to support muscle maintenance in patients with end-stage renal disease (ESRD). Although muscle maintenance is important, adequate removal of uremic toxins throughout hemodialysis is the primary concern for patients. It remains to be established whether intradialytic protein ingestion and/or exercise modulate uremic toxin removal during hemodialysis. METHODS: We recruited 10 patients with ESRD (age: 65 ± 16 y, BMI: 24.2 ± 4.8 kg/m2) on chronic hemodialysis treatment to participate in this randomized cross-over trial. During hemodialysis, patients were assigned to ingest 40 g protein or a nonprotein placebo both at rest (protein [PRO] and placebo [PLA], respectively) and following 30 min of exercise (PRO + exercise [EX] and PLA + EX, respectively). Blood and spent dialysate samples were collected throughout hemodialysis to assess reduction ratios and removal of urea, creatinine, phosphate, cystatin C, and indoxyl sulfate. RESULTS: The reduction ratios of urea and indoxyl sulfate were higher during PLA (76 ± 6% and 46 ± 9%, respectively) and PLA + EX interventions (77 ± 5% and 45 ± 10%, respectively) when compared to PRO (72 ± 4% and 40 ± 8%, respectively) and PRO + EX interventions (73 ± 4% and 43 ± 7%, respectively; protein effect: P = .001 and P = .023, respectively; exercise effect: P = .25 and P = .52, respectively). Nonetheless, protein ingestion resulted in greater urea removal (P = .046) during hemodialysis. Reduction ratios and removal of creatinine, phosphate, and cystatin C during hemodialysis did not differ following intradialytic protein ingestion or exercise (protein effect: P > .05; exercise effect: P>.05). Urea, creatinine, and phosphate removal were greater throughout the period with intradialytic exercise during PLA + EX and PRO + EX interventions when compared to the same period during PLA and PRO interventions (exercise effect: P = .034, P = .039, and P = .022, respectively). CONCLUSION: The removal of uremic toxins is not compromised by protein feeding and/or exercise implementation during hemodialysis in patients with ESRD.

Purpose To determine the effects of dietary sugar or carbohydrate restriction on physical activity energy expenditure, energy intake, and physiological outcomes across 24 h. Methods In a randomized, open-label crossover design, twenty-five healthy men (n = 10) and women (n = 15) consumed three diets over a 24-h period: moderate carbohydrate and sugar content (MODSUG = 50% carbohydrate [20% sugars], 15% protein, 35% fat); low sugar content (LOWSUG = 50% carbohydrate [ Results The MODSUG, LOWSUG and LOWCHO diets resulted in similar mean [95%CI] rates of both physical activity energy expenditure (771 [624, 919] vs. 677 [565, 789] vs. 802 [614, 991] kcal·d−1; p = 0.29] and energy intake (2071 [1794, 2347] vs. 2195 [1918, 2473] vs. 2194 [1890, 2498] kcal·d−1; P = 0.34), respectively. The LOWCHO condition elicited the lowest glycaemic and insulinaemic responses to breakfast (P P p Conclusion When energy density is controlled for, restricting either sugar or total dietary carbohydrate does not modulate physical activity level or energy intake over a 24-h period (~ 19-h free-living) despite substantial metabolic changes. Clinical trials registration ID NCT03509610, https://clinicaltrials.gov/show/NCT03509610

NEW FINDINGS: What is the central question of this study? Are biomarkers of endothelial function, oxidative stress and inflammation altered by non-freezing cold injury (NFCI)? What is the main finding and its importance? Baseline plasma [interleukin-10] and [syndecan-1] were elevated in individuals with NFCI and cold-exposed control participants. Increased [endothelin-1] following thermal challenges might explain, in part, the increased pain/discomfort experienced with NFCI. Mild to moderate chronic NFCI does not appear to be associated with either oxidative stress or a pro-inflammatory state. Baseline [interleukin-10] and [syndecan-1] and post-heating [endothelin-1] are the most promising candidates for diagnosis of NFCI. ABSTRACT: Plasma biomarkers of inflammation, oxidative stress, endothelial function and damage were examined in 16 individuals with chronic NFCI (NFCI) and matched control participants with (COLD, n = 17) or without (CON, n = 14) previous cold exposure. Venous blood samples were collected at baseline to assess plasma biomarkers of endothelial function (nitrate, nitrite and endothelin-1), inflammation [interleukin-6 (IL-6), interleukin-10 (IL-10), tumour necrosis factor alpha and E-selectin], oxidative stress [protein carbonyl, 4-hydroxy-2-nonenal (4-HNE), superoxide dismutase and nitrotyrosine) and endothelial damage [von Willebrand factor, syndecan-1 and tissue type plasminogen activator (TTPA)]. Immediately after whole-body heating and separately, foot cooling, blood samples were taken for measurement of plasma [nitrate], [nitrite], [endothelin-1], [IL-6], [4-HNE] and [TTPA]. At baseline, [IL-10] and [syndecan-1] were increased in NFCI (P < 0.001 and P = 0.015, respectively) and COLD (P = 0.033 and P = 0.030, respectively) compared with CON participants. The [4-HNE] was elevated in CON compared with both NFCI (P = 0.002) and COLD (P < 0.001). [Endothelin-1] was elevated in NFCI compared with COLD (P < 0.001) post-heating. The [4-HNE] was lower in NFCI compared with CON post-heating (P = 0.032) and lower than both COLD (P = 0.02) and CON (P = 0.015) post-cooling. No between-group differences were seen for the other biomarkers. Mild to moderate chronic NFCI does not appear to be associated with a pro-inflammatory state or oxidative stress. Baseline [IL-10] and [syndecan-1] and post-heating [endothelin-1] are the most promising candidates for diagnosing NFCI, but it is likely that a combination of tests will be required.

Purpose: Wetsuits have been shown to change swim biomechanics and, thus, increase performance, but not all athletes are comfortable with their use because of possible modifications in motor coordination. The aim of this study was to evaluate the effects of wetsuit use on biomechanical, physiological, and perceptual variables. Methods: Eleven national- and international-level triathletes, familiar with wetsuit use, performed 7 × 200-m front crawl at constant preset speed twice, with and without a full wetsuit. The trunk incline (TI) and index of coordination (IdC) were measured stroke by stroke using video analysis. Stroke, breaths, and kick count, and timing (as breathing/kick action per arm-stroke cycle); stroke length (SL); and underwater length were analyzed using inertial-measurement-unit sensors. Heart rate (HR), rating of perceived exertion (RPE), and swimming comfort were monitored during the task. Results: A lower TI; IdC; number of strokes, kicks, and breaths; HR; and RPE for each 200 m were found in wetsuit compared with swimsuit condition. Higher values of SL and underwater length were found in wetsuit, whereas no differences were found in swimming comfort and timing of kicks and breaths. An increase for swimsuit condition in number of strokes and breaths, HR, and RPE was found during the task compared with the first 200 m. Conclusion: Wetsuit use reduces TI and, thus, drag; increases propelling proficiency; and shows lower fatigability, without modifying motor coordination, compared with swimsuit use at the same speed. The use of a wetsuit during training sessions is recommended to increase comfort and the positive effects on performance.

OBJECTIVE: This study aimed to assess the impact of time-restricted eating (TRE) on integrated skeletal muscle myofibrillar protein synthesis (MyoPS) rates in males with overweight/obesity.METHODS: A total of 18 healthy males (age 46 ± 5 years; BMI: 30 ± 2 kg/m2 ) completed this exploratory, parallel, randomized dietary intervention after a 3-day lead-in diet. Participants then consumed an isoenergetic diet (protein: ~1.0 g/kg body mass per day) following either TRE (10:00 a.m. to 6:00 p.m.) or an extended eating control (CON; 8:00 a.m. to 8:00 p.m.) protocol for 10 days. Integrated MyoPS rates were measured using deuterated water administration with repeated saliva, blood, and muscle sampling. Secondary measures included continuous glucose monitoring and body composition (dual-energy x-ray absorptiometry).RESULTS: There were no differences in daily integrated MyoPS rates (TRE: 1.28% ± 0.18% per day, CON: 1.26% ± 0.22% per day; p = 0.82) between groups. From continuous glucose monitoring, 24-hour total area under the curve was reduced following TRE (-578 ± 271 vs. CON: 12 ± 272 mmol/L × 24 hours; p = 0.001). Total body mass declined (TRE: -1.6 ± 0.9 and CON: -1.1 ± 0.7 kg; p CONCLUSION: Consuming food within an 8-hour time-restricted period does not lower daily MyoPS rates when compared with an isoenergetic diet consumed over 12 hours. Future research should investigate whether these results translate to free-living TRE.

This narrative review paper aimed to discuss the literature on machine learning applications in soccer with an emphasis on injury risk assessment. A secondary aim was to provide practical tips for the health and performance staff in soccer clubs on how machine learning can provide a competitive advantage. Performance analysis is the area with the majority of research so far. Other domains of soccer science and medicine with machine learning use are injury risk assessment, players' workload and wellness monitoring, movement analysis, players' career trajectory, club performance, and match attendance. Regarding injuries, which is a hot topic, machine learning does not seem to have a high predictive ability at the moment (models specificity ranged from 74.2%-97.7%. sensitivity from 15.2%-55.6% with area under the curve of 0.66-0.83). It seems, though, that machine learning can help to identify the early signs of elevated risk for a musculoskeletal injury. Future research should account for musculoskeletal injuries' dynamic nature for machine learning to provide more meaningful results for practitioners in soccer..

Belgium has one of the highest numbers of COVID-19 cases per 1 million inhabitants. The pandemic has led to significant societal changes with repercussions on sleep and on mental health. We aimed to investigate the effect of the first and the second wave of COVID-19 on the sleep of the Belgian populationWe launched two online questionnaires, one during the first lockdown (7240 respondents) and one during the second (3240 respondents), to test differences in self-reported clinical insomnia (as measured by the Insomnia Severity Index) and sleep habits during the two lockdowns in comparison with the pre-COVID period. The number of persons with clinical insomnia rose during the first lockdown (19.22%) and further during the second (28.91%) in comparison with pre-lockdown (7.04-7.66%). Bed and rise times were delayed and there was an increased time in bed and sleep onset latency. There was further a decrease in total sleep time and in sleep efficiency during both confinements. The prevalence of clinical insomnia quadrupled during the second wave in comparison with the pre-lockdown situation. Sleep habits were most altered in the younger population, indicating a greater risk for this group to develop a sleep-wake rhythm disorder.

This study aimed to assess, for the first time, how self-reported sleep, mental toughness, and reaction time are impacted by a professional padel tournament. In addition, we evaluated whether sex, age, and/or ranking play a role in this possible effect of a tournament on these variables. Twenty-three professional players (15 men, Mage = 24 ± 6 years; eight women, Mage = 21 ± 5 years) were evaluated on two occasions: (a) baseline, in a noncompetitive week and (b) postmeasure, the morning after an individual was eliminated from the tournament. The Pittsburgh Sleep Quality Index, the Mental Toughness Questionnaire, and the psychomotor vigilance task were used to evaluate the dependent variables. Wilcoxon tests or paired samples t tests were employed to assess the effect of participating in the tournament. To test correlations between variables, Pearson correlation coefficients (quantitative variables) or chi-square distributions (qualitative variables) were employed. Results showed that self-reported sleep (p < .01), mental toughness (p = .01), and reaction time (p = .04) were significantly impaired by the tournament. Exploring moderating variables, results showed that mental toughness did not correlate with sleep impairments (p > .05). In contrast, a nearly significant correlation between sleep impairments and higher reaction times was found (p = .066). No significant effects of age, sex, and ranking were observed. In conclusion, participating in a padel competition impairs the self-reported sleep, mental toughness, and reaction time of professional padel players. A trend toward a significant correlation between the competition-related impairment in sleep and reaction time was observed, whereas age, ranking, and sex were not found to be moderators of any of these impairments.

ObjectivesTo assess the adverse impact of the first 5 months of androgen deprivation therapy on body composition, physical performance, cardiometabolic health and health-related quality-of-life in prostate cancer patients.Materials and MethodsThirty-four prostate cancer patients (70 +/- 7 years) were assessed shortly after initiation of androgen deprivation therapy and again 5 months thereafter. Measurements consisted of whole-body dual-energy x-ray absorptiometry (body composition), computed tomography scanning of the upper leg (muscle mass), one-repetition maximum leg press (muscle strength), cardiopulmonary exercise testing (aerobic capacity), blood draws (metabolic parameters), accelerometry (habitual physical activity) and questionnaires (health-related quality-of-life). Data were analyzed with Student's paired t-tests.ResultsOver time, whole-body fat mass (from 26.2 +/- 7.7 to 28.4 +/- 8.3 kg, p < 0.001) and fasting insulin (from 9.5 +/- 5.8 to 11.3 +/- 6.9 mU/L, p < 0.001) increased. Declines were observed for quadriceps cross-sectional area (from 66.3 +/- 9.1 to 65.0 +/- 8.5 cm(2), p < 0.01), one-repetition maximum leg press (from 107 +/- 27 to 100 +/- 27 kg, p < 0.01), peak oxygen uptake (from 23.2 +/- 3.7 to 20.3 +/- 3.4 mL/min/kg body weight, p < 0.001), step count (from 7,048 +/- 2,277 to 5,842 +/- 1,749 steps/day, p < 0.01) and health-related quality-of-life (from 84.6 +/- 13.5 to 77.0 +/- 14.6, p < 0.001).ConclusionsAndrogen deprivation therapy induces adverse changes in body composition, muscle strength, cardiometabolic health and health-related quality-of-life already within 5 months after the start of treatment, possibly largely contributed by diminished habitual physical activity. Prostate cancer patients should, therefore, be stimulated to increase their habitual physical activity immediately after initiation of androgen deprivation therapy, to limit adverse side-effects and to improve health-related quality-of-life.

Background: Ingestion of protein concentrates or isolates increases muscle protein synthesis rates in young and older adults. There is far less information available on the anabolic response following the ingestion of dairy wholefoods, which are commonly consumed in a normal diet. Objectives: This study investigates whether ingestion of 30 g protein provided as quark increases muscle protein synthesis rates at rest and whether muscle protein synthesis rates are further increased after resistance exercise in young and older adult males. Methods: In this parallel-group intervention trial, 14 young (18–35 y) and 15 older (65–85 y) adult males ingested 30 g protein provided as quark after a single-legged bout of resistance exercise on leg press and leg extension machines. Primed, continuous intravenous L-[ring- 13C 6]-phenylalanine infusions were combined with the collection of blood and muscle tissue samples to assess postabsorptive and 4-h postprandial muscle protein synthesis rates at rest and during recovery from exercise. Data represent means ± SDs; η 2 was used to measure the effect size. Results: Plasma total amino acid and leucine concentrations increased after quark ingestion in both groups (both time: P < 0.001; η 2 > 0.8), with no differences between groups (time × group: P = 0.127 and P = 0.172, respectively; η 2−1) and older adult males (from 0.036 ± 0.011 to 0.062 ± 0.013 %·h −1), with a further increase in the exercised leg (to 0.071 ± 0.023 %·h −1 and to 0.078 ± 0.019 %·h −1, respectively; condition: P < 0.001; η 2 = 0.716), with no differences between groups (condition × group: P = 0.747; η 2 = 0.011). Conclusions: Quark ingestion increases muscle protein synthesis rates at rest with a further increase following exercise in both young and older adult males. The postprandial muscle protein synthetic response following quark ingestion does not differ between healthy young and older adult males when an ample amount of protein is ingested. This trial was registered at the Dutch Trial register, which is accessible via trialsearch.who.int www.trialregister.nl as NL8403.

OBJECTIVE: To systematically investigate and document the infrastructure, practices, recommendations, and clinical consequences of a structured, organized sports cardiology multidisciplinary team (MDT) for athletes and patients who wish to engage in sports and exercise. PATIENTS AND METHODS: We established bimonthly sports cardiology MDT meetings, with a permanent panel of experts in sports cardiology, genetics, pediatric cardiology, cardiovascular imaging, electrophysiology, and sports and exercise medicine. Cases were referred nationally or internationally by cardiologists/sports physicians. We retrospectively analyzed all MDT cases (April 10, 2019 through May 13, 2020) and collected clinical follow-up data up to 1 year after the initial review. RESULTS: A total of 115 athletes underwent MDT review; of them, 11% were women, 65% were recreational athletes, and 54% were performing "mixed" type of sports; the mean age was 32±16 years. An MDT review led to a diagnosis revision of "suspected cardiac pathology" to "no cardiac pathology" in 38% of the athletes and increased the number of definitive diagnoses (from 77 to 109; P=.03). We observed fewer "total sports restrictions" (from 6 to 0; P=.04) and more tailored sports advice concerning "no peak load/specific maximum load" (from 10 to 26; P=.02). At the 14±6-month follow-up, 112 (97%) athletes reported no cardiovascular events, 111 (97%) athletes reported no (new) cardiac symptoms, 113 (98%) athletes reported adherence to the MDT sports advice, and no diagnoses were revised. CONCLUSION: Our experiences with a comprehensive sports cardiology MDT demonstrate that this approach leads to higher percentages of definitive diagnoses and fewer cardiac pathology diagnoses, more tailored sports advice with excellent rates of adherence, and fewer total sports restrictions. Our findings highlight the added value of sports cardiology MDTs for patient and athlete care.

BACKGROUND: Clinical trials inform on average efficacy, but individualized risk assessments for outcome prediction are important in guiding treatment implementation. OBJECTIVES: The authors developed and validated a patient-specific risk score to predict survival at 1 and 2 years after HeartMate 3 (HM3) left ventricular assist device (LVAD) implantation. METHODS: The MOMENTUM 3 (Multicenter Study of MagLev Technology in Patients Undergoing Mechanical Circulatory Support Therapy with HeartMate 3) trial includes 2,200 HM3 LVAD patients in the pivotal trial and Continued Access Protocol study (2014-2018). The authors randomly assigned all patients to a derivation cohort (n = 1,540) or validation cohort (n = 660). Univariate mortality predictors were screened for potential model inclusion, stepwise selection was used to build the multivariable Cox proportional hazards regression model, and performance (discrimination and calibration) was evaluated. RESULTS: Age, prior cardiac surgery (coronary artery bypass grafting [CABG] or valve procedure), lower serum sodium, higher blood urea nitrogen (BUN), small left ventricular size, and right atrial pressure-to-pulmonary capillary wedge pressure (RAP/PCWP) ratio >0.6 were significant risk factors for mortality. Receiver-operating characteristic (ROC) analysis in the validation cohort demonstrated an area under the curve (AUC) of 0.76 (95% CI: 0.70-0.81) at 1 year and 0.71 (95% CI: 0.66-0.77) at 2 years. Calibration between predicted and observed survival of the risk quintiles was high, with Pearson correlation coefficients of 0.986 and 0.994 at 1 and 2 years, respectively. Patients were successfully stratified into tertiles with higher-than-average, average, and lower-than-average survival, and observed mortality risk increased by 2-fold from one tertile to the next. CONCLUSIONS: A practical, easy-to-use HM3 Survival Risk Score with 6 components was developed to accurately predict 1- and 2-year survival after HM3 LVAD implantation. The survival risk score can be used to provide individual survival estimates to facilitate shared decision making when considering HM3 LVAD therapy. (MOMENTUM 3 Trial Portfolio; NCT02224755, NCT02892955).

OBJECTIVE: Identifying which types of athletes have increased injury risk (ie, predictive risk factors) should help develop cost-effective selective injury prevention strategies. Our objective was to compare a theoretical injury risk classification system developed by coaches and rehabilitation therapists, with observed injury rates in human circus acts across dimensions of physical stressors, acrobatic complexity, qualifications, and residual risks. DESIGN: Descriptive epidemiological study. SETTING: professional circus company. PATIENTS OR OTHER PARTICIPANTS: Human circus artists performing in routine roles between 2007 and 2017. ASSESSMENT OF RISK FACTORS: Characteristics of circus acts categorized according to 4 different dimensions. MAIN OUTCOME MEASURES: Medical attention injury rates (injury requiring a visit to the therapist), time-loss injury rates (TL-1; injury resulting in at least one missed performance), and time-loss 15 injury rates (TL-15; injury resulting in at least 15 missed performances). RESULTS: Among 962 artists with 1 373 572 performances, 89.4% (860/962) incurred at least one medical attention injury, 74.2% (714/962) incurred at least one TL-1 injury, and 50.8% (489/962) incurred at least one TL-15 injury. There were important inconsistencies between theoretical and observed injury risk patterns in each of the 4 dimensions for all injury definitions (medical attention, TL-1, and TL-15). CONCLUSIONS: Although theoretical classifications are the only option when no data are available, observed risk patterns based on injury surveillance programs can help identify artists who have a high (or low) theoretical risk but are nonetheless actually at low (or high) risk of injury, given their current roles. This will help develop more cost-effective selective injury prevention programs.

Experts have highlighted the importance of coaches knowing the level of mental fatigue (MF) induced by different tasks. This study aimed to compare the mentally fatiguing nature of cognitive, physical, and combined tasks and, additionally, assess the effect of different moderating variables on MF. Twenty-three physically active (16 males: Mage = 24 years; seven females: Mage = 22.57 years) participants performed three experimental sessions: (a) physically fatiguing: 30 min of cycloergometer work (at 65%–75% of maximum heart rate), (b) mentally fatiguing: 30 min of an incongruent Stroop task, and (c) mixed fatiguing: 30 min of combining the physically and mentally fatiguing protocols. Subjective MF (visual analog scale), reaction time (psychomotor vigilance task), and cognitive performance (Stroop) were measured throughout the different protocols. Results showed significant increments in subjective MF after all tasks, with the mental and mixed protocols showing significantly higher increases. Only the mentally fatiguing protocol caused significant impairments in reaction time. No significant effects of sex, years of experience, or degree of mental toughness were observed. These results suggest that the use of all these tasks, and especially the mentally fatiguing exercises, should be avoided immediately prior to competitions due to the negative consequences of MF on performance. Moreover, this effect seems to be independent of the sex, years of experience, or mental toughness of athletes.

PURPOSE: This study investigated the effects of both an active warm-up and the time-of-day variation on repeated-sprint performance. A second objective was to compare the post-exercise recovery between the experimental conditions. METHODS: Eleven male participants performed ten maximal cycling sprints (6 s each, with a 30-s interval between them) in the morning and late afternoon, either after a warm-up or control condition. The warm-up consisted of cycling for 10 min at 50% of the peak aerobic power. RESULTS: Rest measurements of rectal, muscle, and skin temperatures were higher in the afternoon compared to the morning (p

Rationale: Dietary protein may attenuate the muscle atrophy experienced by patients in the ICU, yet protein handling is poorly understood. Objectives: To quantify protein digestion and amino acid absorption and fasting and postprandial myofibrillar protein synthesis during critical illness. Methods: Fifteen mechanically ventilated adults (12 male; aged 50 ± 17 yr; body mass index, 27 ± 5 kg⋅m-2) and 10 healthy control subjects (6 male; 54 ± 23 yr; body mass index, 27 ± 4 kg⋅m-2) received a primed intravenous L-[ring-2H5]-phenylalanine, L-[3,5-2H2]-tyrosine, and L-[1-13C]-leucine infusion over 9.5 hours and a duodenal bolus of intrinsically labeled (L-[1-13C]-phenylalanine and L-[1-13C]-leucine) intact milk protein (20 g protein) over 60 minutes. Arterial blood and muscle samples were taken at baseline (fasting) and for 6 hours following duodenal protein administration. Data are mean ± SD, analyzed with two-way repeated measures ANOVA and independent samples t test. Measurements and Main Results: Fasting myofibrillar protein synthesis rates did not differ between ICU patients and healthy control subjects (0.023 ± 0.013% h-1 vs. 0.034 ± 0.016% h-1; P = 0.077). After protein administration, plasma amino acid availability did not differ between groups (ICU patients, 54.2 ± 9.1%, vs. healthy control subjects, 61.8 ± 13.1%; P = 0.12), and myofibrillar protein synthesis rates increased in both groups (0.028 ± 0.010% h-1 vs. 0.043 ± 0.018% h-1; main time effect P = 0.046; P-interaction = 0.584) with lower rates in ICU patients than in healthy control subjects (main group effect P = 0.001). Incorporation of protein-derived phenylalanine into myofibrillar protein was ∼60% lower in ICU patients (0.007 ± 0.007 mol percent excess vs. 0.017 ± 0.009 mol percent excess; P = 0.007). Conclusions: The capacity for critically ill patients to use ingested protein for muscle protein synthesis is markedly blunted despite relatively normal protein digestion and amino acid absorption.

NEW FINDINGS: What is the central question of this study? Ischaemic preconditioning is a novel pre-exercise priming strategy. We asked whether ischaemic preconditioning would alter mitochondrial respiratory function and pulmonary oxygen uptake kinetics and improve severe-intensity exercise performance. What is the main finding and its importance? Ischaemic preconditioning expedited overall pulmonary oxygen uptake kinetics and appeared to prevent an increase in leak respiration, proportional to maximal electron transfer system and ADP-stimulated respiration, that was evoked by severe-intensity exercise in sham-control conditions. However, severe-intensity exercise performance was not improved. The results do not support ischaemic preconditioning as a pre-exercise strategy to improve exercise performance in recreationally active participants. ABSTRACT: We examined the effect of ischaemic preconditioning (IPC) on severe-intensity exercise performance, pulmonary oxygen uptake ( V ̇ O 2 ${\dot V_{{{\rm{O}}_{\rm{2}}}}}$ ) kinetics, skeletal muscle oxygenation (muscle tissue O2 saturation index) and mitochondrial respiration. Eight men underwent contralateral IPC (4 × 5 min at 220 mmHg) or sham-control (SHAM; 20 mmHg) before performing a cycling time-to-exhaustion test (92% maximum aerobic power). Muscle (vastus lateralis) biopsies were obtained before IPC or SHAM and ∼1.5 min postexercise. The time to exhaustion did not differ between SHAM and IPC (249 ± 37 vs. 240 ± 32 s; P = 0.62). Pre- and postexercise ADP-stimulated (P) and maximal (E) mitochondrial respiration through protein complexes (C) I, II and IV did not differ (P > 0.05). Complex I leak respiration was greater postexercise compared with baseline in SHAM, but not in IPC, when normalized to wet mass (P = 0.01 vs. P = 0.19), mitochondrial content (citrate synthase activity, P = 0.003 vs. P = 0.16; CI+IIP, P = 0.03 vs. P = 0.23) and expressed relative to P (P = 0.006 vs. P = 0.30) and E (P = 0.004 vs. P = 0.26). The V ̇ O 2 ${\dot V_{{{\rm{O}}_{\rm{2}}}}}$ mean response time was faster (51.3 ± 15.5 vs. 63.7 ± 14.5 s; P = 0.003), with a smaller slow component (270 ± 105 vs. 377 ± 188 ml min-1 ; P = 0.03), in IPC compared with SHAM. The muscle tissue O2 saturation index did not differ between trials (P > 0.05). Ischaemic preconditioning expedited V ̇ O 2 ${\dot V_{{{\rm{O}}_{\rm{2}}}}}$ kinetics and appeared to prevent an increase in leak respiration through CI, when expressed proportional to E and P evoked by severe-intensity exercise, but did not improve exercise performance.

Cardiac sequelae after COVID-19 have been described in athletes, prompting the need to establish a return-to-play (RTP) protocol to guarantee a safe return to sports practice. Sports participation is strongly associated with multiple short- and long-term health benefits in children and adolescents and plays a crucial role in counteracting the psychological and physical effects of the current pandemic. Therefore, RTP protocols should be balanced to promote safe sports practice, particularly after an asymptomatic SARS-CoV-2 infection that represents the common manifestation in children. The present consensus document aims to summarize the current evidence on the cardiac sequelae of COVID-19 in children and young athletes, providing key messages for conducting the RTP protocol in paediatric athletes to promote a safe sports practice during the COVID-19 era.

Esports are a contemporary phenomenon, with millions of people involved. Still, scientific literature on the topic is scarce. Anecdotal reports, mostly based on what is known from videogames practice, have associated esports with unhealthy lifestyles and health-related problems. The present scoping review aimed to provide an overview of findings from studies regarding the health and well-being in adult esports players, while identifying the most studied topics in the field and those still lacking scientific research.The search was conducted in MEDLINE, Scopus, Web of Science, B-on, and ESCBO databases. Studies regarding health consequences of esports practice conducted with adult esports players were included. No exclusion criteria concerning age, sex, esports modality, or esports level were applied, but articles related to other forms of video gaming or gambling were excluded. The search was limited to peer-reviewed articles. Opinion and review articles were excluded.There were 1416 articles retrieved from which 33 met the inclusion criteria. Lifestyle habits, sleep, exercise and physical health (including musculoskeletal health), physiological demands, and mental health were the main topics of investigation. Several gaps in the literature were identified, namely studies on cardiovascular, respiratory, or metabolic health, or consuming-related risks. Also, the lack of homogeneous methodologies and definitions used in esports-related studies was identified.Esports practice has been associated with different health-related symptoms, but more studies using more robust methodologies and appropriate research design are needed. Topics such as cardiovascular health or the use of performance-enhancing drugs are lacking.Anecdotal reports have associated esports with unhealthy lifestyles and health-related problems. Still, scientific literature about esports is scarce. The current scoping review aimed to better understand health and well-being in esports players, while identifying the topics most studied in the field and those which might still be lacking scientific knowledge.Lifestyle habits, sleep characteristics, exercise and physical health, including musculoskeletal health, physiological demands, and mental health were the main topics approached within the 33 articles included in the present scoping review. Several gaps in the literature were identified, namely studies on cardiovascular, respiratory, or metabolic health, or consuming-related risks. Also, the lack of homogeneous methodologies and definitions used in the esports scene was identified.Esports practice has been associated with different health-related symptoms, but studies on esports using robust methodologies and appropriate research design are needed. Studies on topics such as cardiovascular health or the use of performance-enhancing drugs are lacking.

Background: The objective was to compare the performance in field tests, dynamic knee valgus, knee function, and kinesiophobia of soccer players who were psychologically ready and not ready to return to unrestricted training or competitions after ACL reconstruction. Methods: Thirty-five male soccer players who had undergone primary ACL reconstruction at least 6 months were divided based on the Anterior Cruciate Ligament Return to Sport after Injury (ACL-RSI) questionnaire score into ready (≥60) and not-ready (

Introduction: Menopause is associated with vascular dysfunction and increased risk of developing metabolic syndrome. Associations between vascular and metabolic health, and interactions with aerobic exercise training, are unknown in postmenopausal women (PMW). Methods: In habitually aerobically trained PMW (PMWtr; n = 10; 57 ± 1 years; 40 ± 1 mL/kg/min), strain-gauge plethysmography was used to compare resting and peak calf blood flow (CBFr and CBFpk, respectively) and vascular resistance (CVRr; CVRpk) versus untrained PMW (PMWun; n = 13; 56 ± 1 years; 29 ± 1 mL/kg/min) and premenopausal women (PreM; n = 14; 26 ± 1 years; 40 ± 1 mL/kg/min). Vascular measures were taken before and 1 hour after 45 minutes of aerobic exercise (60% V ̇O 2peak), a known nitric oxide stimulus. Blood analyses included low- (LDLc) and high-density lipoprotein cholesterol (HDLc), insulin, and glucose. Results: Pre-exercise, CBFr and CVRr did not differ (p > 0.05) between PMW groups, nor between PreM and PMWtr. CBFpk was highest (p < 0.05) and CVRpk was lowest (p < 0.05) in PMWtr. Blood markers were similar (p > 0.05) in PMW groups. However, in PMWtr, CBFpk was associated inversely (p < 0.05) with insulin (r = −0.725). Conversely, in PMWun, CBFpk correlated (p < 0.05) inversely with glucose (r = −0.717), positively with HDLc (r = 0.633), and CVRpk positively (p < 0.05) with LDLc (r = 0.568). Post-exercise, CBF increased and CVR decreased (p < 0.05) in all groups, yet CBFpk remained higher and CVRpk lower (p < 0.05) in PMWtr. Conclusion: In untrained PMW, peak CBF is associated inversely with circulating pro-atherogenic lipids and glucose. In contrast, peak CBF is associated inversely with insulin levels only in trained PMW. Habitual aerobic exercise may favorably modulate vasculo-metabolic interactions in PMW.

Rapid oscillations in cytosolic calcium (Ca2+) coordinate muscle contraction, relaxation, and physical movement. Intriguingly, dietary nitrate decreases ATP cost of contraction, increases force production, and increases cytosolic Ca2+, which would seemingly necessitate a greater demand for sarcoplasmic reticulum Ca2+ ATPase (SERCA) to sequester Ca2+ within the sarcoplasmic reticulum (SR) during relaxation. As SERCA is highly regulated, we aimed to determine the effect of 7-day nitrate supplementation (1 mM via drinking water) on SERCA enzymatic properties and the functional interaction between SERCA and mitochondrial oxidative phosphorylation. In soleus, we report that dietary nitrate increased force production across all stimulation frequencies tested, and throughout a 25 min fatigue protocol. Mice supplemented with nitrate also displayed an ∼25% increase in submaximal SERCA activity and SERCA efficiency (P = 0.053) in the soleus. To examine a possible link between ATP consumption and production, we established a methodology coupling SERCA and mitochondria in permeabilized muscle fibers. The premise of this experiment is that the addition of Ca2+ in the presence of ATP generates ADP from SERCA to support mitochondrial respiration. Similar to submaximal SERCA activity, mitochondrial respiration supported by SERCA-derived ADP was increased by ∼20% following nitrate in red gastrocnemius. This effect was fully attenuated by the SERCA inhibitor cyclopiazonic acid and was not attributed to differences in mitochondrial oxidative capacity, ADP sensitivity, protein content, or reactive oxygen species emission. Overall, these findings suggest that improvements in submaximal SERCA kinetics may contribute to the effects of nitrate on force production during fatigue.NEW & NOTEWORTHY We show that nitrate supplementation increased force production during fatigue and increased submaximal SERCA activity. This was also evident regarding the high-energy phosphate transfer from SERCA to mitochondria, as nitrate increased mitochondrial respiration supported by SERCA-derived ADP. Surprisingly, these observations were only apparent in muscle primarily expressing type I (soleus) but not type II fibers (EDL). These findings suggest that alterations in SERCA properties are a possible mechanism in which nitrate increases force during fatiguing contractions.

Objective: To develop a trail running injury screening instrument (TRISI) for utilisation as clinical decision aid in determining if a trail runner is at an increased risk for injury. Design: Multiple methods approach. Methods: The study utilised five phases 1) identification of injury risk factors 2) determining the relevance of each identified risk factor in a trail running context, 3) creating the content of the Likert scale points from 0 to 4, 4) rescaling the Likert scale points to determine numerical values for the content of each Likert scale point, and 5) determining a weighted score for each injury risk factor that contributes to the overall combined composite score. Results: Of the 77 identified injury risk factors, 26 were deemed relevant in trail running. The weighted score for each injury risk factor ranged from 2.21 to 5.53 with the highest calculated score being 5.53. The final TRISI includes risk categories of training, running equipment, demographics, previous injury, behavioural, psychological, nutrition, chronic disease, physiological, and biomechanical factors. Conclusion: The developed TRISI aims to assist the clinician during pre-race injury screening or during a training season to identify meaningful areas to target in designing injury risk management strategies and/or continuous health education.

INTRODUCTION: Mental fatigue (MF) is a psychobiological state that impairs cognitive as well as physical performance in different settings. Recently, numerous studies have sought ways to counteract these negative effects of MF. An overview of the explored countermeasures for MF is, however, lacking. OBJECTIVES: The objective of this review is to provide an overview of the different MF countermeasures currently explored in literature. Countermeasures were classified by the timing of application (before, during or after the moment of MF) and type of intervention (behavioural, physiological and psychological). METHODS: The databases of PubMed (MEDLINE), Web of Science and PsycINFO were searched until March 7, 2022. Studies were eligible when MF was induced using a task with a duration of at least 30 min, when they assessed MF markers in at least two out of the three areas wherein MF markers have been defined (i.e., behavioural, subjective and/or [neuro]physiological) and used a placebo or control group for thecountermeasure. RESULTS: A total of 33 studies investigated one or more countermeasures against MF. Of these, eight studies assessed a behavioural countermeasure, 22 a physiological one, one a psychological countermeasure and two a combination of a behavioural and psychological countermeasure. The general finding was that a vast majority of the countermeasures induced a positive effect on behavioural (e.g., task or sport performance) and/or subjective MF markers (e.g., visual analogue scale for MF or alertness). No definitive conclusion could be drawn regarding the effect of the employed countermeasures on (neuro)physiological markers of MF as only 19 of the included studies investigated these measures, and within these a large heterogeneity in the evaluated (neuro)physiological markers was present. DISCUSSION: Within the physiological countermeasures it seems that the use of odours during a MF task or caffeine before the MF task are the most promising interventions in combating MF. Promising behavioural (e.g., listening to music) and psychological (e.g., extrinsic motivation) countermeasures of MF have also been reported. The most assumed mechanism through which these countermeasures operate is the dopaminergic system. However, this mechanism remains speculative as (neuro)physiological markers of MF have been scarcely evaluated to date. CONCLUSION: The present systematic review reveals that a wide range of countermeasures have been found to successfully counteract MF on a subjective, (neuro)physiological and/or behavioural level. Of these, caffeine, odours, music and extrinsic motivation are the most evidenced for countering MF. To provide in-detail practical guidelines for the real-life application of MF countermeasures, more research must be performed into the underlying mechanisms and into the optimal dosage and time of application/intake.

This study aimed to analyse the reproducibility of mean power output during 20-min cycling time-trials, in a remote home-based setting, using the virtual-reality cycling software, Zwift. Forty-four cyclists (11 women, 33 men; 37±8 years old, 180±8 cm, 80.1±13.2 kg) performed 3×20-min time-trials on Zwift, using their own setup. Intra-class correlation coefficient (ICC), coefficient of variation (CV) and typical error (TE) were calculated for the overall sample, split into 4 performance groups based on mean relative power output (25% quartiles) and sex. Mean ICC, TE and CV of mean power output between time-trials were 0.97 [0.95–0.98], 9.4 W [8.0–11.3 W], and 3.7% [3.2–4.5], respectively. Women and men had similar outcomes (ICC: 0.96 [0.89–0.99] vs. 0.96 [0.92–0.98]; TE: 8.3 W [6.3–13.1] vs. 9.7 W [8.2–12.2]; CV: 3.8% [2.9–6.1] vs. 3.7% [3.1–4.7], respectively), although cyclists from the first quartile showed a lower CV in comparison to the overall sample (Q1: 2.6% [1.9–4.1] vs. overall: 3.7% [3.2–4.5]). Our results indicate that power output during 20-min cycling time-trials on Zwift are reproducible and provide sports scientists, coaches and athletes, benchmark values for future interventions in a virtual-reality environment.