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The primary aim of this study was to determine the association between body composition and performance outcomes in youth soccer players. Twenty-five competitive male youth soccer players (age = 13.7 ± 0.8 years, height = 167.4 ± 9.7 cm, weight = 57.6 ± 12.1 kg) volunteered to participate in this study. Height and weight were used to calculate body mass index (BMI). Body fat percentage (BF%) and fat-free mass (FFM) were determined with dual-energy X-ray absorptiometry. Each athlete performed the Pacer test, vertical jump, and t-test drill. Participants were predominantly normal weight (20.4 ± 2.7 kg·m−2). The body composition results were 20.3 ± 4.9% for BF% and 46.5 ± 8.7 kg for FFM. The results of the performance tests indicated a mean ± standard deviation (SD) of 1418 ± 332 m for Pacer, 57.2 ± 7.4 cm for vertical jump, 11.6 ± 0.7 s for t-test. Body mass index was not associated with any performance measure (r = 0.02 to −0.21, all p > 0.05). Body fat percentage was associated with the Pacer, vertical jump, and t-test (r = −0.62, −0.57, 0.61, respectively; all p < 0.01) and remained after accounting for BMI. Fat-free mass was only significantly related to t-test (r = −0.43, p < 0.01). However, after controlling for BMI, FFM was related to all three performance tests. Body fat percentage and FFM are associated with performance in youth soccer players, with stronger relationships reported in the former metric. The findings highlight the need for accurate body composition measurements as part of an assessment battery in young athletes. [ABSTRACT FROM AUTHOR]

Research examining potential differences in physical activity (PA) between sexual minority women (SMW) and heterosexual women have yielded inconsistent results. OBJECTIVE: Therefore, the purpose of this systematic review and meta-analysis is to examine potential differences in PA between SMW and heterosexual women and to identify potential moderators that may partially explain observed differences in PA. METHODS: All studies were peer reviewed, published in English, and included a continuous measure of PA for SMW and heterosexual women. A standardized mean difference effect size (ES) was used to compare groups, with random effects models used to estimate a mean ES and 95% CI using a 3-level meta-analysis model to adjust for the correlation between effects nested within studies. RESULTS: The cumulative results of 24 effects gathered from 7 studies indicated there was no difference in PA between SMW (n = 1619) and heterosexual women (n = 103,295) (ES = -0.038, 95%CI -0.179 to 0.102, p = 0.576). Despite no mean differences, moderate-high heterogeneity was observed, indicating that the results were not consistent across effects (I 2 = 64.8%, Q 23 = 36.7, p = 0.035). The difference in PA was associated with age (β = −0.018, 95%CI -0.034 to −0.003, p = 0.022) and BMI (β = −0.145, 95%CI -0.228 to −0.061, p = 0.002), with a quadratic relationship observed for both variables. CONCLUSIONS: Although the results of the current analysis did not indicate significant differences in PA behaviors between SMW and heterosexual women, age and BMI modify the association and are curvilinear in nature; such that smaller differences in PA were observed between SMW and heterosexual women when samples were middle-aged and overweight. • Physical activity behaviors among sexual minority and heterosexual women may differ. • Differences in physical activity were associated with age and body mass index. • Smaller differences in physical activity observed among middle-age and overweight women. [ABSTRACT FROM AUTHOR]

Physical activity (PA) has a variety of well-established benefits for physical and mental health. However, there are PA disparities based on numerous sociodemographic characteristics, including sexual orientation. Mapping of PA interventions tailored to sexual minorities (ie, nonheterosexual) is currently absent from the literature., Purpose: The purpose of this scoping review was to summarize the existing interventions focused on promoting PA among sexual minority (SM) adults., Methods: A search strategy was developed in consultation with a research librarian for PubMed, Web of Science, SportDiscus, and CINAHL. The scoping review was conducted using the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews guidelines. Randomized and nonrandomized interventions that focused on increasing PA among SM adults were included. Data on study design, sample demographics, purpose of research, methodology, intervention components, theory-based constructs used, PA measures, and outcomes of the intervention were extracted., Results: Our search yielded 7289 articles, with 26 articles requiring full-text review. Four interventions were identified that focused on increasing PA among SM adults, with 2 focusing on lesbian/bisexual women, 1 focusing on lesbian/gay cancer survivors, and 1 focusing on men who have sex with men. Two of the 4 studies were successful at increasing PA, with varying psychosocial theories (ie, social cognitive theory and theory of reasoned action) and intervention strategies (ie, PA counseling, group meetings, and pedometers)., Conclusion: Findings of this review demonstrate a clear lack of PA interventions targeting SM adults, limiting the available knowledge required for preventionists, practitioners, and health care professionals to effectively promote PA through behavioral modification among this group.

Resisted sprint (RS) training, such as sled or parachute towing, is commonly used for sprint training among field sport athletes. While RS training is frequently employed by athletes and coaches, there is little research on its benefits, especially compared to unresisted running (UR) training programs with similar training volumes. This systematic review and meta-analysis compared the effectiveness of RS training on acceleration compared to UR training. Potential sources were limited to peer-reviewed articles published in English prior to June 12, 2022, and gathered from the EBSCOhost, PubMed, and Web of Science online databases identified using combinations of the following terms: towing , sled , " resisted sprint ," " sprint acceleration ," " sprint performance ," and " sprint speed ." The search returned 1,159 sources, from which 15 were eligible for inclusion. Fifty effects were used to estimate the impact of RS training on initial sprint speed. Based on the cumulative results from these studies, RS training yielded a small improvement in acceleration but was not different from same volume of UR training (Hedges' d Effect Size=0.11, 95% CI: -0.01 to 0.23; p=0.08). These results do not support the use of RS training over UR training for improving initial sprint speed; however, further research should be conducted.

The purpose of this study was to investigate lower limb blood flow responses under varying blood flow restriction (BFR) pressures based on individualized limb occlusion pressures (LOP) using a commonly used occlusion device. Twenty-nine participants (65.5% female, 23.8 ± 4.7 years) volunteered for this study. An 11.5cm tourniquet was placed around participants' right proximal thigh, followed by an automated LOP measurement (207.1 ± 29.4mmHg). Doppler ultrasound was used to assess posterior tibial artery blood flow at rest, followed by 10% increments of LOP (10-90% LOP) in a randomized order. All data were collected during a single 90-minute laboratory visit. Friedman's and one-way repeated-measures ANOVAs were used to examine potential differences in vessel diameter, volumetric blood flow (VolFlow), and reduction in VolFlow relative to rest (%Rel) between relative pressures. No differences in vessel diameter were observed between rest and all relative pressures (all p < .05). Significant reductions from rest in VolFlow and %Rel were first observed at 50% LOP and 40% LOP, respectively. VolFlow at 80% LOP, a commonly used occlusion pressure in the legs, was not significantly different from 60% ( p = .88), 70% ( p = .20), or 90% ( p = 1.00) LOP. Findings indicate a minimal threshold pressure of 50%LOP may be required to elicit a significant decrease in arterial blood flow at rest when utilizing the 11.5cm Delfi PTSII tourniquet system.

The purpose of this study was to determine the relationship between changes in heart rate variability (HRV), neuromuscular performance, and fatigue biomarkers in response to a resistance exercise bout. The root mean square of successive RR interval differences (RMSSD), neuromuscular performance - isometric handgrip (IHG), countermovement jump (CMJ), mean propulsive velocity (MPV) - metabolic stress (lactate [Lac]) and inflammation (interleukin-6 [IL-6]) were measured in 30 subjects who performed 6×10 back squat (BS), 3×10 bench press (BP), and 3×10 bent-over rows (BR) at 70% of 1-repetition maximum (1RM). The RMSSD, neuromuscular performance, and biomarkers were measured 10 min pre-exercise and 30 min post-exercise (Post 30 ); HRV and Lac were also measured immediately post-exercise (Post 0 ). Pre- versus post-exercise differences were evaluated using paired-samples t -tests. Pearson's correlations were used to determine the association between changes. With the exception of IL-6 (P=0.296) and MPV BP (P=0.678), LnRMSSD, neuromuscular performance, and metabolic stress were different post- compared to pre-exercise. We observed moderate associations between ΔLnRMSSD Post 0 and ΔLac Post 0 ( r = -0.44) and ΔLac Post 30 ( r = -0.55), respectively. Practitioners should use multiple training load indicators to gain an accurate depiction of recovery.