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Purpose: The long-term development of talent in endurance sports is a topic of interest. Among various factors, the importance of total hemoglobin mass (tHb_mass) and the potential benefits of being an altitude-native athlete remain unclear, particularly in young categories. This study aimed to investigate the impact of altitude and training content on hematological characteristics by comparing young male cyclists age 15–16 and 17–18 years who were born and trained at a moderate altitude (ie, greater than or equal to 2500 m; MA) and cyclists who were born and trained at low altitude (below 1000 m; LA). Methods: tHb_mass (in grams and grams per kilogram), measured by using the optimized carbon monoxide rebreathing method during an incremental test on a cycle ergometer; hematocrit percentage, hemoglobin concentration; and erythrocyte, blood, and plasma volume were measured in youth male cyclists age 15–16 years and junior cyclists age 17–18 years who were born and trained at MA versus LA. All variables were analyzed with a 2-way (age [youth cyclist vs junior cyclist] × altitude level [MA vs LA]) analysis of variance with subsequent Tuckey post hoc test. Results and Conclusion: Some altitude-induced benefits were reported in cyclists at age 15–16 years in the MA group with higher values in hematocrit percentage, hemoglobin concentration, and tHb_mass (grams per kilogram) (P < .05) than their LA counterparts. This was also observed at age 17–18 years (P < .001), except for tHb_mass, wherein no significant difference was found between MA and LA groups. In contrast, plasma volume was lower in MA than LA junior cyclists. New Findings : (1) The altitude of birth and residence could generate an advantage in tHb_mass in young male cyclists age 15–16 and 17–18 years who train at MA compared with cyclists who are born and train at LA. (2) Altitude-induced benefits in physiological variables (hematocrit percentage, hemoglobin concentration, tHb_mass in g·kg⁻¹) were reported in cyclists at age 15–16 years and partially at age 17–18 years. In contrast, plasma volume was lower in MA than in LA junior cyclists. This may impact the strategies for identifying and developing talent in cycling.

Purpose: We examined the reliability of force parameters derived from the isometric midthigh pull (IMTP) and their correlation with the functional capacities of young soccer players. Methods: Data were collected from 20 young professional soccer players within and between 2 sessions (after 1 wk) using a 1000-Hz force plate. Results: Performance outputs in all IMTP parameters were consistent and showed moderate to excellent reliability (intraclass correlation coefficient = .72–1.00) within and between sessions. However, all parameters reported a marginal ability to detect chronic changes in performance (smallest worthwhile change [SWC] < standard error of measurement [SEM]) except for peak vertical force (PF) parameters, which showed good usefulness (SWC > SEM). Absolute PF was correlated with the countermovement-jump (CMJ) total impulse (CMJ-TI; r = .54), whereas relative PF (to body mass) was correlated with CMJ height, CMJ peak power, and the last speed of the 30:15 Intermittent Fitness Test (V _IFT; r = .40 to .63). IMTP time-dependent forces were correlated with CMJ-TI (r = .52 to .62). The IMTP impulse parameters were positively correlated with CMJ-TI (r = .48 to .58) and negatively with V _IFT (r = −.44 to −.38). None of the IMTP parameters were correlated either with the CMJ mean propulsive force or with any linear acceleration times. Conclusions: All IMTP parameters can be adopted by practitioners involved with testing young soccer players based on their acceptable reliability criteria. However, caution should be taken when interpreting the time-dependent variables based on their marginal usefulness when assessing performance. Generally, a greater PF was associated with a greater vertical power based on its correlation to CMJ.

Purpose: Adequate physical fitness is a key requirement for elite footballers. Maximal fitness tests are the standard for evaluating fitness but are often fatiguing and time consuming. This study investigated the ability of various minimally invasive protocols to reflect changes in standard parameters of football players’ physical fitness. Methods: Twenty-one elite junior footballers performed 2 standard fitness tests (stepwise incremental treadmill test with blood-lactate and heart-rate [HR] measurements and Yo-Yo Intermittent Recovery 1 test) and various proxy fitness evaluations (submaximal runs with measurement of exercise HR and HR recovery and external-to-internal load ratios with data collected during match play) 3 times over the course of 19 weeks. Changes in the standard parameters were compared with changes in proxy parameters. Results: Changes in maximal endurance performance showed small to moderate associations with HR-based proxy parameters (r = −.1 to −.46; P = .004–.56), whereas changes in the running velocity at anaerobic threshold had trivial to moderate associations (r = −.07 to −.39; P = .01–.67). Alterations in HR recovery following 2 short, submaximal runs were very largely correlated with changes in the running velocity corresponding to an HR of 170 beats·min⁻¹ (r = −.74 and r = –.75; P < .001). Changes in external-to-internal load ratios derived from match play were not significantly correlated with changes in any of the standard parameters (r = −.03 to .31; P > .05). Conclusions: Parameters of maximal running performance and parameters describing physiological thresholds do not seem to be adequately captured by different minimally invasive protocols. In contrast, HR recovery following short, submaximal runs may be a valid tool to monitor changes in aerobic endurance adaptations.

Balance training paradigms have been shown to effectively reduce fall risk. Visual feedback is an important sensory mechanism for regulating postural control, promoting visual perturbations for balance training paradigms. Stroboscopic goggles, which oscillate from transparent to opaque, are a form of visual perturbation, but their effect on standing balance has not been assessed. In this study, 29 participants stood in bilateral and tandem stances as the center of pressure was recorded for 6 consecutive minutes wherein there were no stroboscopic perturbations in the first and last minutes. Spatial–temporal, frequency domain, and nonlinear standing balance parameters were calculated for each period. More differences in spatial–temporal parameters due to the strobe were found in the medial–lateral direction than the anterior–posterior direction. More differences in frequency domain parameters were observed in the anterior–posterior direction than the medial–lateral direction, but this did not occur for each variable. The nonlinear parameters were strongly affected by the strobe. Stroboscopic perturbations did not affect the bilateral and tandem stances equally. Spatial–temporal parameters for the tandem stance were greater in magnitude during the strobe period than the no strobe periods. This effect was not seen with the bilateral stance. This indicates that the efficacy of stroboscopic perturbations for challenging standing balance depends on task difficulty. Balance training paradigms that utilize stroboscopic perturbations will need to harmonize these perturbations with task difficulty.

Objective: Limited research has directly compared the effectiveness of aqua- and land-based exercises for postexercise recovery. This study aimed to fill this gap by comparing the effects of these 2 types of exercises on postexercise recovery. Methods: Sixteen male college athletes participated in an 8-day experimental study. The initial 2 days were dedicated to determining the intensity levels for the muscle-damaging exercise and recovery jogging. In a crossover design, participants underwent 2 sets of experimental trials. They were randomly assigned to either an aqua or land recovery intervention for days 3 to 5, and after a 1-week washout period they switched to the opposite intervention for days 6 to 8. Muscle soreness, creatine kinase, anaerobic performance, countermovement-jump height, and flexibility were assessed at different time points: baseline, immediately after downhill running, within 1 hour after jogging, and 24 hours and 48 hours after aqua or land jogging. Results: Significant group × time interaction effects were detected in the perceived soreness of the hamstring and quadriceps. However, the post hoc analysis showed no significant difference between aqua and land jogging groups. No significant group × time interaction effect was observed in creatine kinase, anaerobic performance, countermovement-jump height, or flexibility. Conclusion: Aqua and land jogging have similar recovery effects on muscle soreness and performance-based parameters.

Background: The Mamanet Cachibol League (MCL), a community-based model developed in Israel, promotes physical activity and amateur team sports among women. Women in the Arab society have traditionally played few sports, especially team sports. Aims: The study aimed to assess the differences in health indicators and well-being, including psychosomatic symptoms, self-reported health, healthy eating habits, and social support, by comparing Arab women MCL participants and nonparticipants and examines benefits and motivations of community-based team sports for participants. Methods: An explanatory sequential mixed-methods approach included a cross-sectional study with intervention and control groups of Israeli Arab women aged 25–59 years. Two-way analyses of covariance and multiple regression models evaluated demographics, well-being, healthy eating, and social support. Quality in-depth interviews with 30 MCL participants further explained the quantitative findings. Results : MCL participants reported higher self-assessed health (P < .001) and decreased psychosomatic symptoms (P < .001) than nonparticipants. Healthier eating and well-being were also linked to MCL participation. The women sense of belonging improved social interactions, personal and professional happiness, and group dedication. MCL attendees felt empowered because the group advocated equality and valued women. Women said their involvement helped their families. Conclusions: Findings on the MCL community-based model suggest that team sports may serve as an effective tool for promoting health and well-being of Arab women and foster positive community relationships. The sense of belonging and personal empowerment derived from being part of a sports team may also contribute to positive mental health outcomes.

Indoor and outdoor home space may support physical activity (PA) and enhance motor skills (MS). However, there is limited knowledge about how indoor and outdoor home space affect PA and MS parent–child dyads. This cross-sectional study examined whether indoor and outdoor home spaces affect PA and MS in children and their parents. MS was measured with the Test of Gross Motor Development-3, and moderate to vigorous PA (MVPA) was assessed using accelerometry in 43 and 48 parent–child dyads, respectively. Indoor and outdoor home spaces were self-reported through an online questionnaire. Multiple regression models were fit to determine the relationship between indoor and outdoor home space and MS and MVPA in children and parents separately. Controlling for theory-based covariates, outdoor home space was positively associated with children’s MVPA (p < .05) and parents’ MS (p < .05) but negatively associated with parents’ MVPA (p < .05). Indoor home space was negatively associated with parents’ MS (p < .05). No other significant findings emerged. Findings suggest indoor and outdoor home spaces may play unique roles in supporting PA and MS among parent–child dyads and should be investigated in more rigorous studies.