Unveiling the relationship of physical literacy with muscular fitness and muscle-strengthening activities in adolescents: the EHDLA study.

Objective: This study evaluated the relationship between physical literacy (PL) and muscular fitness (MF) as well as muscle-strengthening activities (MSA) in adolescents. Methods: A secondary cross-sectional study included 823 adolescents (45.1% boys) from the Eating Healthy and Daily Life Activities Study. The Spanish Perceived Physical Literacy Instrument for Adolescents (S-PPLI) assessed the participants' perceived PL. The evaluation of MF in the young population was conducted using the Assessing the Levels of Physical Activity and Fitness (ALPHA-FIT) test battery. MSA were assessed by the following question: 'In the past week, how many days did you exercise to strengthen or tone the muscle, such as through push-ups, sit-ups or lifting weights?' To examine the associations between S-PPLI scores and handgrip strength, standing long jump and MSA days in adolescents, we employed generalised additive models. Results: Participants with high perceived physical literacty (PPL) had the highest handgrip strength (mean=25.1; PPL had the highest handgrip strength (mean=25.1; bias-corrected and accelerated (BCa) bootstrapped 95% CI 24.2 to 26.0) and standing long jump (mean=149.7; confidence interval (CI) 24.2 to 26.0) and standing long jump (mean=149.7; 24.2 to 26.0) and standing long jump (mean=149.7; BCa bootstrapped 95% CI 145.8 to 153.5). Conversely, those adolescents with low PPL had the lowest handgrip strength (mean=23.1; BCa bootstrapped 95% CI 22.3 to 23.8) and standing long jump (mean=137.3; BCa bootstrapped 95% CI 133.9 to 140.6). For MSA, adolescents with high PPL had the highest mean of MSA days (mean=3.0; BCa bootstrapped 95% CI 2.8 to 3.3), while the lowest mean was observed for those with low PPL (mean=2.0; BCa bootstrapped 95% CI 1.8 to 2.2). Conclusion: A high level of PL was associated with higher levels of MF and MSA among Spanish adolescents.

Meeting muscle-strengthening recommendation is associated with lower adiposity, higher physical fitness and healthier lifestyle in adolescents: The EHDLA study.

AIM: To determine the prevalence of adolescents who meet muscle-strengthening activities (MSA) recommendation and their associations with anthropometric variables, physical fitness, and lifestyle behaviours in a sample of Spanish adolescents aged 12-17 years. METHODS: This was a cross-sectional study using data from The Eating Healthy and Daily Life Activities (EHDLA) Study. Participants reported the days on which they engaged in MSA (≥3 days per week were considered to meet World Health Organization recommendation). Physical fitness was assessed with the ALPHA fitness battery. Additionally, body mass index, waist circumference, skinfolds and body fat percentage were assessed. Lifestyle variables were recreational screen time, sleep time and adherence to the Mediterranean diet. The associations between MSA and outcome variables were tested with linear and logistic regressions. RESULTS: Of the 852 participants, 48% met MSA recommendation. Meeting MSA recommendation was associated with lower adiposity and higher performance in the shuttle run test, maximal oxygen consumption, standing long jump, speed-agility, flexibility, lower screen time (in weekdays) and higher adherence to the Mediterranean diet. CONCLUSION: Engaging in MSA once or twice a week was linked with more desirable health outcomes than not engaging in such activities. However, meet with MSA recommendation (i.e., at least 3 days per week) reinforced these benefits.

May the Force Be with Youth: Foundational Strength for Lifelong Development.

ABSTRACT: Today's youth are weaker than previous generations, and measurable reductions in physical fitness are beginning to emerge. Without targeted initiatives that recognize the foundational importance of resistance training, weaker children and adolescents may be more likely to experience the inevitable consequences of neuromuscular dysfunction and less likely to experience the pleiotropic benefits of exercise and sport. Early exposure to strength-building activities is needed to prepare today's youth for ongoing participation in varied physical activities throughout this developmental phase of life. The novel iceberg of physical development is a metaphoric image that illustrates the sequential and cumulative influence of muscular strength on motor skills and physical abilities. Efforts to enhance the physical capacity of youth should include resistive skills that improve basic movement patterns and enhance motoric competence. A shift in our conceptual thinking about youth resistance training is needed to alter the current trajectory toward physical inactivity and related comorbidities.

Efficacy of Postprandial Exercise in Mitigating Glycemic Responses in Overweight Individuals and Individuals with Obesity and Type 2 Diabetes-A Systematic Review and Meta-Analysis.

Studies investigating the acute effect of postprandial exercise (PPE) on glucose responses exhibit significant heterogeneity in terms of participant demographic, exercise protocol, and exercise timing post-meal. As such, this study aimed to further analyze the existing literature on the impact of PPE on glycemic control in overweight individuals and individuals with obesity and type 2 diabetes (T2DM). A literature search was conducted through databases such as PubMed, CINAHL, and Google Scholar. Thirty-one original research studies that met the inclusion criteria were selected. A random-effect meta-analysis was performed to compare postprandial glucose area under the curve (AUC) and 24 h mean glucose levels between PPE and the time-matched no-exercise control (CON). Subgroup analyses were conducted to explore whether the glucose-lowering effect of PPE could be influenced by exercise duration, exercise timing post-meal, and the disease status of participants. This study revealed a significantly reduced glucose AUC (Hedges' g = -0.317; SE = 0.057; p < 0.05) and 24 h mean glucose levels (Hedges' g = -0.328; SE = 0.062; p < 0.05) following PPE compared to CON. The reduction in glucose AUC was greater (p < 0.05) following PPE lasting >30 min compared to ≤30 min. The reduction in 24 h mean glucose levels was also greater (p < 0.05) following PPE for ≥60 min compared to <60 min post-meal and in those with T2DM compared to those without T2DM. PPE offers a viable approach for glucose management and can be performed in various forms so long as exercise duration is sufficient. The glucose-lowering effect of PPE may be further enhanced by initiating it after the first hour post-meal. PPE is a promising strategy, particularly for patients with T2DM. This manuscript is registered with Research Registry (UIN: reviewregistry1693).

Effects of Resistance Training on Academic Outcomes in School-Aged Youth: A Systematic Review and Meta-Analysis.

BACKGROUND: The primary aim of our systematic review and meta-analysis was to investigate the effect of resistance training on academic outcomes in school-aged youth. METHODS: We conducted a systematic search of six electronic databases (CINAHL Complete, PsycINFO, SCOPUS, Ovid MEDLINE, SPORTDiscus and EMBASE) with no date restrictions. Studies were eligible if they: (a) included school-aged youth (5-18 years), and (b) examined the effect of resistance training on academic outcomes (i.e., cognitive function, academic achievement, and/or on-task behaviour in the classroom). Risk of bias was assessed using the appropriate Cochrane Risk of Bias Tools, funnel plots and Egger's regression asymmetry tests. A structural equation modelling approach was used to conduct the meta-analysis. RESULTS: Fifty-three studies were included in our systematic review. Participation in resistance training (ten studies with 53 effect sizes) had a small positive effect on the overall cognitive, academic and on-task behaviours in school-aged youth (standardized mean difference (SMD) 0.19, 95% confidence interval (CI) 0.05-0.32). Resistance training was more effective (SMD 0.26, 95% CI 0.10-0.42) than concurrent training, i.e., the combination of resistance training and aerobic training (SMD 0.11, 95% CI - 0.05-0.28). An additional 43 studies (including 211 effect sizes) examined the association between muscular fitness and cognition or academic achievement, also yielding a positive relationship (SMD 0.13, 95% CI 0.10-0.16). CONCLUSION: This review provides preliminary evidence that resistance training may improve cognitive function, academic performance, and on-task behaviours in school-aged youth. PROSPERO REGISTRATION: CRD42020175695.

Time-of-Day Effects of Exercise on Cardiorespiratory Responses and Endurance Performance-A Systematic Review and Meta-Analysis.

ABSTRACT: Kang, J, Ratamess, NA, Faigenbaum, AD, Bush, JA, Finnerty, C, DiFiore, M, Garcia, A, and Beller, N. Time-of-day effects of exercise on cardiorespiratory responses and endurance performance-A systematic review and meta-analysis. J Strength Cond Res 37(10): 2080-2090, 2023-The time-of-day effect of exercise on human function remains largely equivocal. Hence, this study aimed to further analyze the existing evidence concerning diurnal variations in cardiorespiratory responses and endurance performance using a meta-analytic approach. Literature search was conducted through databases, including PubMed, CINAHL, and Google Scholar. Article selection was made based on inclusion criteria concerning subjects' characteristics, exercise protocols, times of testing, and targeted dependent variables. Results on oxygen uptake (V̇ o2 ), heart rate (HR), respiratory exchange ratio, and endurance performance in the morning (AM) and late afternoon or evening (PM) were extracted from the chosen studies. Meta-analysis was conducted with the random-effects model. Thirty-one original research studies that met the inclusion criteria were selected. Meta-analysis revealed higher resting V̇ o2 (Hedges' g = -0.574; p = 0.040) and resting HR (Hedges' g = -1.058; p = 0.002) in PM than in AM. During exercise, although V̇ o2 remained indifferent between AM and PM, HR was higher in PM at submaximal (Hedges' g = -0.199; p = 0.046) and maximal (Hedges' g = -0.298; p = 0.001) levels. Endurance performance as measured by time-to-exhaustion or the total work accomplished was higher in PM than in AM (Hedges' g = -0.654; p = 0.001). Diurnal variations in V̇ o2 appear less detectable during aerobic exercise. The finding that exercising HR and endurance performance were greater in PM than in AM emphasizes the need to consider the effect of circadian rhythm when evaluating athletic performance or using HR as a criterion to assess fitness or monitor training.

Assessment of Physical Tests in 6-11 Years Old Children: Findings from the Play Lifestyle and Activity in Youth (PLAY) Study.

The purpose was to evaluate selected physical tests in children and to compare the outcomes by sex. A cross-sectional study design was used to evaluate children 6-11 years who completed five physical tests: hand grip, vertical jump, sit and reach, Y-balance, and obstacle course (time and score). The outcome measures including test results were descriptively examined and compared by sex. The study participants consisted of 133 children (62 males and 71 females, with a median age of 7.8 years). Girls showed superior sit and reach performance (p = 0.002) compared with boys. Boys demonstrated better Y-balance scores (p = 0.007) and faster obstacle time (p = 0.042) than girls. Sex comparison within three age groups (6-<8 years, 8-<10 years, and 10-<12 years) showed that girls performed better on the sit and reach compared with boys in the in 6-<8 years (p = 0.009). Boys demonstrated higher Y-balance scores (p = 0.017) and faster obstacle time (p = 0.007) compared with girls in the 8-<10-year age group. These data will serve to guide future efforts to evaluate normative measures of physical literacy and guide targeted training interventions to promote sustained physical activity in children with deficits relative to their age and sex norms.

Efficacy of school-based interventions for improving muscular fitness outcomes in children: A systematic review and meta-analysis.

The World Health Organization recommends that children should engage in an average of 60 min of moderate-to-vigorous physical activity (MVPA) per day and should perform activities that strengthen muscle and bone at least 3 days a week. Public health professionals as well as pediatric researchers have identified schools as a strategic place to promote muscular strength development. Thus, the aim of this systematic review and meta-analysis was to investigate the efficacy of school-based exercise interventions for improving muscular fitness (MF) in children. Searches were conducted in three databases. Eligible criteria were randomized and non-randomized controlled trials evaluating the effects of school-based exercise interventions on MF (i.e. muscular strength, muscular power, and local muscular endurance) in children under 13 years of age. Risk of bias by the National Institutes of Health tool was appraised, and pooled effect sizes (Hedges'g) were calculated using random-effects inverse-variance analyses. Seventeen studies enrolling 1653 children (28% girls were analyzed). Exercise interventions, mostly combined interventions targeting selected domains of MF, were associated with significant moderate increases in local muscular endurance (g = 0.65 95% CI, 0.13 to 1.17, p = 0.020; I2 = 85.0%) and muscular strength and muscular power (g = 0.33 95% CI, 0.16 to 0.51, p = 0.001; I2 = 59.3%), with higher effects using interventions with ≥3 sessions per week. Our findings indicate that school-based exercise that includes strength building exercises may improve MF in children and, consequently, prepare modern day youth for the demands of exercise and sport activities. HighlightsSchool-based muscle and bone strengthening exercises performed at least 3 days per week may serve to support the development of muscular fitness in girls and boysIntegrative interventions that include a variety of strength and conditioning activities seem to be a promising strategy to promote muscular fitness in school environmentFuture research should standardize assessment methods for use with children in the school context and should include interventions with girlsIt is of interest to a growing number of health care providers, fitness professionals and physical education teachers to encourage participation in well-designed muscle and bone strengthening exercises.

Top 10 International Priorities for Physical Fitness Research and Surveillance Among Children and Adolescents: A Twin-Panel Delphi Study.

BACKGROUND: The measurement of physical fitness has a history that dates back nearly 200 years. Recently, there has been an increase in international research and surveillance on physical fitness creating a need for setting international priorities that could help guide future efforts. OBJECTIVE: This study aimed to produce a list of the top 10 international priorities for research and surveillance on physical fitness among children and adolescents. METHODS: Using a twin-panel Delphi method, two independent panels consisting of 46 international experts were identified (panel 1 = 28, panel 2 = 18). The panel participants were asked to list up to five priorities for research or surveillance (round 1), and then rated the items from their own panel on a 5-point Likert scale of importance (round 2). In round 3, experts were asked to rate the priorities identified by the other panel. RESULTS: There was strong between-panel agreement (panel 1: rs = 0.76, p < 0.01; panel 2: rs = 0.77, p < 0.01) in the priorities identified. The list of the final top 10 priorities included (i) "conduct longitudinal studies to assess changes in fitness and associations with health". This was followed by (ii) "use fitness surveillance to inform decision making", and (iii) "implement regular and consistent international/national fitness surveys using common measures". CONCLUSIONS: The priorities identified in this study provide guidance for future international collaborations and research efforts on the physical fitness of children and adolescents over the next decade and beyond.

A Comparison of Warm-Up Effects on Maximal Aerobic Exercise Performance in Children.

The aim of this study was to compare the warm-up effects of treadmill walking (TW) with a dynamic (DY) bodyweight warm-up on maximal aerobic exercise performance in children. Sixteen children (10.9 ± 1.5 vrs) were tested for peak oxygen uptake (VO2 peak) on 2 nonconsecutive days following different 6 min warm-up protocols. TW consisted of walking on a motor-driven treadmill at 2.2 mph and 0% grade whereas the DY warm-up consisted of 9 body weight movements including dynamic stretches, lunges, and jumps. Maximal heart rate was significantly higher following DY than TW (193.9 ± 6.2 vs. 191.6 ± 6.1 bpm, respectively; p = 0.008). VO2 peak (54.8 ± 9.6 vs. 51.8 ± 8.7 mL/kg/min; p = 0.09), maximal minute ventilation (68.9 ± 14.8 vs. 64.9 ± 9.4 L/min; p = 0.27), maximal respiratory exchange ratio (1.12 ± 0.1 vs. 1.11 ± 0.1; p = 0.85) and total exercise time (614.0 ± 77.1 vs. 605 ± 95.0 s; p = 0.55) did not differ significantly between DY and TM warm-ups, respectively. These findings indicate that the design of the warm-up protocol can influence the heart rate response to maximal aerobic exercise and has a tendency to influence VO2 peak. A DY warm-up could be a viable alternative to a TW warm-up prior to maximal exercise testing in children.

Integrative Neuromuscular Training in Adolescents and Children Treated for Cancer (INTERACT): Study Protocol for a Multicenter, Two-Arm Parallel-Group Randomized Controlled Superiority Trial.

Background: Improved survival rates for children and adolescents diagnosed with cancer call for novel strategies for reducing short- and long-term treatment-related side effects. These include the physical and metabolic sequelae that are exacerbated by sedentary behavior and treatment-induced toxicities. We aim to investigate the effect of an integrative neuromuscular training intervention during the first 6 months of anti-cancer treatment primarily on muscle strength, and secondarily on exercise capacity, physical function, markers of metabolic syndrome, dysmetabolism, and health-related quality of life during and after ended treatment. Methods: One hundred and twenty-seven children and adolescents, newly diagnosed with malignant and benign neoplasia, aged 6-17 years, and treated with chemotherapy or radiation will be randomized to either the intervention or the control arm of the study. The intervention group will, in addition to usual care, be offered a combination of 6 months of supervised physical exercise (integrative neuromuscular training) and home-based exercise. The active control group will, in addition to usual care, receive information along an unsupervised written home-based training program. All participants, including parents, will receive information about the importance of physical exercise during the course of cancer treatment, at the start of treatment, and in 5 monthly sessions. The primary outcome is measured in terms of isometric quadriceps muscle strength. Secondary outcomes include muscle strength and endurance, markers of metabolic syndrome and dysmetabolism, exercise capacity, physical function and activity, days of hospitalization, and health-related quality of life. Assessment will be conducted at treatment initiation (baseline), at 3 and 6 months after inclusion, and 1 month and 1 year after ended treatment. The primary endpoint for lower-body muscle strength is at 6 months after treatment initiation. The effects of the intervention will be evaluated through a constrained linear mixed model. Discussion: This national randomized controlled study has the potential to provide new knowledge concerning the short- and long-term effects of a novel, inclusive approach for youth exercise programming (integrative neuromuscular exercise) in children and adolescents during anti-cancer treatment. Using a pragmatic, low-cost, and time-efficient training design, this intervention can be easily adapted to both hospital and home settings. Clinical Trial Registration: ClinicalTrials.gov (NCT04706676), first released January 5, 2021.

Preliminary Report on the Train the Brain Project, Part II: Neuroplasticity of Augmented Neuromuscular Training and Improved Injury-Risk Biomechanics.

CONTEXT: Neuromuscular training (NMT) facilitates the acquisition of new movement patterns that reduce the anterior cruciate ligament injury risk. However, the neural mechanisms underlying these changes are unknown. OBJECTIVE: To determine the relationship between brain activation and biomechanical changes after NMT with biofeedback. DESIGN: Cohort study. SETTING: Research laboratory. PATIENTS OR OTHER PARTICIPANTS: Twenty female high school soccer athletes, with 10 in an augmented NMT group and 10 in a control (no training) group. MAIN OUTCOME MEASURE(S): Ten participants completed 6 weeks of NMT augmented with real-time biofeedback to reduce knee injury-risk movements, and 10 participants pursued no training. Augmented neuromuscular training (aNMT) was implemented with visual biofeedback that responded in real time to injury-risk biomechanical variables. A drop vertical jump with 3-dimensional motion capture was used to assess injury-risk neuromuscular changes before and after the 6-week intervention. Brain-activation changes were measured using functional magnetic resonance imaging during unilateral knee and multijoint motor tasks. RESULTS: After aNMT, sensory (precuneus), visual-spatial (lingual gyrus), and motor-planning (premotor) brain activity increased for knee-specific movement; sensorimotor cortex activity for multijoint movement decreased. The knee-abduction moment during landing also decreased (4.66 ± 5.45 newton meters; P = .02; Hedges g = 0.82) in the aNMT group but did not change in the control group (P > .05). The training-induced increased brain activity with isolated knee movement was associated with decreases in knee-abduction moment (r = 0.67; P = .036) and sensorimotor cortex activity for multijoint movement (r = 0.87; P = .001). No change in brain activity was observed in the control group (P > .05). CONCLUSIONS: The relationship between neural changes observed across tasks and reduced knee abduction suggests that aNMT facilitated recruitment of sensory integration centers to support reduced injury-risk mechanics and improve sensorimotor neural efficiency for multijoint control. Further research is warranted to determine if this training-related multimodal neuroplasticity enhances neuromuscular control during more complex sport-specific activities.

Attitudes and behaviors of physical activity in children: Findings from the Play, Lifestyle & Activity in Youth (PLAY) Questionnaire.

BACKGROUND: The identified domains of child physical literacy include knowledge/understanding, behavior, motivation/confidence, and physical competency. Understanding physical literacy is critical to moving forward intervention efforts surrounding physical inactivity. OBJECTIVES: To investigate physical literacy domains by presenting responses to the Play, Lifestyle & Activity in Youth (PLAY) questionnaire and analyze the relationship between comparable questions in the child and parent sections. DESIGN: Cross-sectional questionnaire study. SETTING: Suburban youth program, United States. MAIN OUTCOME MEASURE: Parent and child responses to the PLAY questionnaire. RESULTS: Questionnaire data were collected for 106 children 6-11 years old and 91 parents. Children (93.3%, 83/91) reported enjoyment in physical education, despite 70% participation in physical education 0-1 day/week. 66.6% (26/91) of children preferred active to passive play and played outside most days/week (5.0 median). Similarly, a high proportion of children (93.3%, 83/91) reported feeling that they physically performed similar to or higher than their peers and took ownership to improve motor competency versus taking a more passive approach. Most children (96.7%, 87/91) reported feeling happy when they were able to play sports/run around, enjoyed gym class (93.3%, 83/91), and reported feeling sad if they cannot play sports/run around during the day (75.6%, 68/91). Parents and children reported rules around screen time and bed time, and reinforced these rules often. Child and parent responses were associated for comparable questions about bedtime and screen-time/media rules, moderate-to-vigorous physical activity per day, sport camp preference, and play equipment use (Fisher's p = .051 screen time, p < .001 other questions). CONCLUSIONS: PLAY questionnaire internal validity showed agreement between comparable parent and child responses and an association for select comparable questions.

Effects of Integrative Neuromuscular Training on Motor Performance in Prepubertal Soccer Players.

ABSTRACT: Menezes, GB, Alexandre, DR, Pinto, JC, Assis, TV, Faigenbaum, AD, and Mortatti, AL. Effects of integrative neuromuscular training on motor performance in prepubertal soccer players. J Strength Cond Res 36(6): 1667-1674, 2022-The present study examined the effects of integrative neuromuscular training (INT) on motor performance in prepubertal soccer players. Subjects were randomly assigned to the experimental group (INT; n = 20, age: 8.2 ± 1.2 years; body mass: 28.4 ± 6.4 kg; height: 1.3 ± 0.1 m) or the control group (CON; n = 18, age: 8.5 ± 1.3 years; body mass: 32.8 ± 8.9 kg; height: 1.3 ± 0.1 m). Integrative neuromuscular training program was performed twice per week during the 12-week training intervention. Balance, flexibility, countermovement vertical jump height (CVJH), sprint speed, and change of direction speed (CODS) were assessed in both groups at baseline, sixth week and 12th week. A mixed model repeated measures analysis of variance was used to examine the group changes in performance for each variable. There was a time effect for balance in the INT from pre to 12th weeks (p < 0.001, g = 0.72), and from 6th to 12th weeks (p = 0.005, g = 0.34). An interaction effect for balance was also observed between INT and CON after the 12th week. A time effect in flexibility was observed in INT from baseline to 6th and 12th weeks (p = 0.02; g = 0.45 and p < 0.001; g = 0.71) and from 6 to 12th weeks (p = 0.003; g = 0.24). There was a time effect in CVJH, from baseline to 12th week and from 6th to 12th weeks (p < 0.05; g = 0.34 and g = 0.53, respectively). There was no significant between-group speed performance change. A time effect was found in CODS in INT, but only from baseline to 12th week (p = 0.02; g = 0.31). There were significant improvements in the percent change (Δ%) from baseline to 12 weeks (p < 0.05) for balance, flexibility, and CVJH in INT. These findings indicate that the addition of an INT program to soccer practice can improve selected motor performance skills in prepubertal soccer players.

Effect of Time-Restricted Feeding on Anthropometric, Metabolic, and Fitness Parameters: A Systematic Review.

Time restricted feeding (TRF) as a form of intermittent fasting (IF) has gained popularity because its ability to reduce body mass (BM) without an emphasis on caloric restriction. However, how this dietary protocol may affect health, fitness, and performance in a relatively healthy cohort remains less clear. The purpose of this article was to systematically review the current literature concerning the effect of TRF on anthropometric, metabolic, and fitness parameters in normal-weight adults and overweight and obese individuals. A systematic search of English literature was conducted through databases including PubMed, CINAHL, and Google Scholar. The search was facilitated by using various combinations of key words related to nutritional interventions, i.e., IF and TRF, and outcomes of interest, i.e., BM, body composition, glucose, insulin, lipid, fitness, and performance. The article selection was made based on the inclusion and exclusion criteria concerning the participants' characteristics, study design, intervention protocols, and targeted dependent variables. Twenty-three full-text longitudinal randomized and nonrandomized controlled studies were selected for this review. Our analysis indicates that TRF can reduce BM and improve nutrient metabolism in both normal- and over-weight individuals. TRF does not appear to alter protein synthesis and fat-free mass nor hamper aerobic fitness and muscular performance among physically active individuals including athletes. In conclusion, TRF as a more easily adaptable form of IF is a promising dietary approach to improving body composition and metabolic health while maintaining fitness and muscular function. However, more research is needed before this dietary protocol can be fully recommended for athletes especially those competing in sports that demand strength and power.Key teaching points and nutritional relevanceTime-restricted feeding (TRF) differs from other fasting protocols due to its emphasis on restricting eating window rather than caloric intake and can be more easily adopted by simply skipping a meal.Its deemphasis on caloric restriction appeals to many young and physically active individuals wanting to optimize body composition but needing sufficient energy to support their physical training and daily activity.Much of what is known regarding the impact of TRF on fitness and athletic performance was derived from studies that use the Ramadan fasting protocol, which differs from TRF in terms of protocol duration and feeding schedule.This review concludes that TRF is a promising dietary approach to improving body composition and metabolic health while maintaining fitness and muscular function in both normal- and over-weight individuals.Due to limited evidence concerning TRF and athletic performance, more research is needed before this dietary protocol can be fully recommended for athletes especially those competing in sports that demand strength and power.

Comparison of fitness levels between elementary school children with autism spectrum disorder and age-matched neurotypically developing children.

Low physical fitness is associated with reduced physical activity and increased cardiovascular diseases. To date, limited research has compared physical fitness levels between children with and without autism spectrum disorder (ASD). Therefore, the primary aim was to investigate if differences in fitness levels exist between children with ASD and age-matched neurotypically developing children (ND). The second aim was to examine if age, sex, height and weight could be used to predict potential fitness levels. The third aim was to examine if the developmental trajectory of fitness is comparable between children with ASD and ND children. The modified Eurofit test battery was used to compare fitness levels between 244 children aged 4-13 years old (n = 152 ND and n = 92 ASD). Independent samples t tests and regression analyses were used to investigate differences in fitness levels between the two groups. The results indicated that statistically significant differences exist in fitness levels between children with ASD when compared to ND children across all ages, favoring the ND children, with small to large effect sizes noted (p < 0.05, d = 0.36-1.13). Regression analysis could not accurately predict fitness measurements in children with ASD but could for ND children. The developmental trajectories were significantly delayed on the 20 m sprint and standing broad jump for children with ASD when compared to ND children. Future studies should seek to address the disparities in physical fitness experienced by children with ASD by using relevant neuromuscular interventions.

Integrative Neuromuscular Training Enhances Physical Fitness in 6- to 14-Year-Old Rugby Players.

ABSTRACT: Alonso-Aubin, DA, Picón-Martínez, M, Rebullido, TR, Faigenbaum, AD, Cortell-Tormo, JM, and Chulvi-Medrano, I. Integrative neuromuscular training enhances physical fitness in 6- to 14-year-old rugby players. J Strength Cond Res 35(8): 2263-2271, 2021-The purpose of this study was to assess the effects of an 8-week integrative neuromuscular training (INT) program on physical fitness measures in young rugby players. A sample of 138 male rugby players (age range, 6-14 years) was divided into 5 age-related groups: group 1 (G1) (n = 20; age, 7.05 ± 0.58), group 2 (G2) (n = 27; age, 8.57 ± 0.49), group 3 (G3) (n = 31; age, 11.02 ± 0.56), group 4 (G4) (n = 33; age, 13.12 ± 0.58, and group 5 (G5) (n = 27; age, 14.85 ± 1.53 and additionally into 2 game position groups: forwards (FOR) (n = 69) and backs (BAC) (n = 69). Physical fitness measures included the Functional Movement Screen (FMS), dominant and nondominant hand-to-eye coordination, sprint capacity, core muscular endurance, and lower- and upper-body power. Integrative neuromuscular training (INT) included progressive strength, coordination, and speed exercises performed twice per week for 20 minutes. Following INT, significant improvements in selected age-related groups (p < 0.01) were found in total FMS score G3 (effect size [ES] = 0.47), G4 (ES = 0.88), and G5 (ES = 0.58); dominant hand-to-eye coordination G1 (ES = 1.48), G2 (ES = 0.71), G3 (ES = 0.55), G4 (ES = 1.47), and G5 (ES = 1.15), nondominant hand-to-eye coordination G2 (ES = 0.74), G4 (ES = 1.34), and G5 (ES = 1.09); lower-body power G2 (ES = 0.44), G4 (ES = 0.39), and G5 (ES = 0.43); core muscular endurance G1 (ES = 0.82), G3 (ES = 0.68), and G4 (ES = 1.04); upper-body power G2 (ES = 0.53); and sprint capacity G4 (ES = 0.69). Significant improvements were also found between player's positions for all tests. These findings indicate that a progressive INT program can enhance functional movement abilities and selected physical fitness measures in young rugby players regardless of game position and age.