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Background: Physical fitness has been considered an important health indicator. Several factors can impact the increase in physical fitness in children and adolescents, including chronological age, sex and BMI, in addition to training variables such as weekly frequency, session and intervention duration, and types of exercises performed. To know the importance of variables that can impact physical fitness, it is important for health professionals to identify the most efficient way of prescribing physical exercises for children and adolescents. The aim is review and meta-analyses of the effects of supervised and structured physical exercise on the physical fitness trainability of children and adolescents. Methods: Relevant articles were searched in the PubMed, Cochrane Library, Embase and Scopus platform databases and selected based on the following criteria: children and adolescents aged between 7 and 17 years who performed any type of structured physical exercise compared to a control group without exercise and evaluating physical fitness (strength or muscular power, cardiorespiratory fitness (CRF) or speed. The results are reported in accordance with PRISMA 2020. Results: Eighty studies were included with a total of 5769 participants. Strength exercises (ES: 1.073; 95% CI, 0.612–1.533; P < 0.001; I2: 74%), concurrent (ES: 1.054; 95% CI, 0.255–1.853; P < 0.010; I2: 72%) and sports (ES: 0.573; 95% CI, 0.015 to 1.132; P < 0.044; I2: 34%) seem to be the most effective in increasing muscular strength. Aerobic activities (ES: 0.400; 95% CI, 0.258–0.542; P < 0.001; I2: 74%), sports (ES: 0.271; 95% IC, 0.148–0.394; P < 0.001; I2: 15), or HIIT (ES: 0.668; 95% IC, 0.333–1.003; P < 0.001; I2: 29%) resulted in increased CRF (ES: 0.514; 95% IC, 0.220–1.808; P < 0.001; I2: 66%). The practice of physical exercise increased muscular power (ES: 0.241; 95% CI, 0.053–0.429; P = 0.012; I2: 0%). The practice of HIIT impacts MAS gains (ES: 0.048; 95% CI, 0.050 − 0.026; P = 0.029; I2: 44%). Conclusion: Supervised and structured physical exercise can improve muscular strength (15–35%), CRF (5.4–8.5%), muscular power (5.6–11.8%), and MAS (5.4%) trainability in children and adolescents. Sex, BMI of the subjects and type of exercise performed (aerobic activities, exclusive to strength, HIIT or sports) should be considered when prescribing the exercise. [ABSTRACT FROM AUTHOR]

This study compared inter-individual variability in the adaptive responses of cardiorespiratory fitness, anaerobic power, and motor abilities of male volleyball players to high-intensity interval training (HIIT) prescribed as repetitive drop jumps (interval jumping) and running-based intervals (interval running). Twenty-four collegiate volleyball players were equally randomized to two training groups executing 11 minutes of interval running or interval jumping during which they ran or repeated drop-jumps for 15 seconds, alternating with 15 seconds of passive recovery. Before and after the 6-week training period, aerobic fitness, cardiac function, and anaerobic power were evaluated using a graded exercise test, impedance cardiography, and a lower-body Wingate test, respectively. Additionally, linear speed, agility, and jumping tests determined motor abilities. Both interventions significantly enhanced maximum oxygen uptake (VO2max), velocity associated with VO2max, first and second ventilatory thresholds (VT1 & VT2), maximal cardiac output (Qmax), stroke volume (SVmax), peak and average power output, vertical jump, change of direction, and linear sprint speed. Interval jumping group demonstrated a significantly greater improvement in squat jump (p = 0.001; 95% CI: 2.51 - 5.42) and countermovement jump (p = 0.001; 95% CI: 2.11 - 4.61) compared to interval running group. Conversely, interval running group elicited a greater enhancement in sprint speed (p = 0.002; 95% CI: 2.53 - 5.71) than interval jumping group. Examining the individual residual in the adaptive responses revealed that interval running induced more homogenized adaptations across individuals in VT1 (p = 0.04; 95% CI: 0.03 - 1.33), Qmax (p = 0.03; 95% CI: 0.04 - 1.64), SVmax (p = 0.04; 95% CI: 0.02 - 1.75), and maximal sprint speed (p = 0.01; 95% CI: 0.72 - 1.95) in contrast to interval jumping. However, the uniformity of adaptations in countermovement jump in response to interval jumping surpassed that of interval running (p = 0.02; 95% CI: 0.08 - 1.32). Although both training modalities effectively improved the mentioned variables concurrently, tailoring the HIIT intervention to the reference intensity and training modality specific for each quality may enhance measured quality. [ABSTRACT FROM AUTHOR]

Betaine supplementation, a dietary practice that possesses potential effects on exercise performance, has undergone extensive study. This study aimed to systematically review and meta-analyse betaine supplementation's effects on exercise performance. We searched PubMed, Web of Science, Scopus, and Google Scholar, focusing on studies comparing chronic betaine to a placebo in healthy humans aged 15–60 years, measuring exercise outcomes. Studies with acute betaine supplementation, no control group, or animals were excluded. Quality assessment was done using the Cochrane Risk of Bias Tool, and a random-effects model was employed for the meta-analysis. The review included 17 studies with 317 participants (21% female). The results revealed a significant effect size of 0.47 (95% CI 0.04 to 0.89) for maximal strength (1RM, 3RM, maximal isokinetic or isometric force), particularly in the lower body (SMD: 0.49, 95% CI 0.01 to 0.98). No significant effects were found for upper body strength, cycling sprint power, bench press throws power, or muscular endurance. However, vertical jumping performance improved significantly (SMD: 0.36, 95% CI 0.03 to 0.69) after excluding a low-quality study. In conclusion, betaine supplementation for at least 7 days significantly enhances muscular strength, especially lower body strength, and shows potential in improving vertical jumping performance. [ABSTRACT FROM AUTHOR]

Abstract Background Physical fitness has been considered an important health indicator. Several factors can impact the increase in physical fitness in children and adolescents, including chronological age, sex and BMI, in addition to training variables such as weekly frequency, session and intervention duration, and types of exercises performed. To know the importance of variables that can impact physical fitness, it is important for health professionals to identify the most efficient way of prescribing physical exercises for children and adolescents. The aim is review and meta-analyses of the effects of supervised and structured physical exercise on the physical fitness trainability of children and adolescents. Methods Relevant articles were searched in the PubMed, Cochrane Library, Embase and Scopus platform databases and selected based on the following criteria: children and adolescents aged between 7 and 17 years who performed any type of structured physical exercise compared to a control group without exercise and evaluating physical fitness (strength or muscular power, cardiorespiratory fitness (CRF) or speed. The results are reported in accordance with PRISMA 2020. Results Eighty studies were included with a total of 5769 participants. Strength exercises (ES: 1.073; 95% CI, 0.612–1.533; P

Abstract Background Climbing is an intricate sport composed of various disciplines, holds, styles, distances between holds, and levels of difficulty. In highly skilled climbers the potential for further strength-specific adaptations to increase performance may be marginal in elite climbers. With an eye on the upcoming 2024 Paris Olympics, more climbers are trying to maximize performance and improve training strategies. The relationships between muscular strength and climbing performance, as well as the role of strength in injury prevention, remain to be fully elucidated. This narrative review seeks to discuss the current literature regarding the effect of resistance training in improving maximal strength, muscle hypertrophy, muscular power, and local muscular endurance on climbing performance, and as a strategy to prevent injuries. Main Body Since sport climbing requires exerting forces against gravity to maintain grip and move the body along the route, it is generally accepted that a climber`s absolute and relative muscular strength are important for climbing performance. Performance characteristics of forearm flexor muscles (hang-time on ledge, force output, rate of force development, and oxidative capacity) discriminate between climbing performance level, climbing styles, and between climbers and non-climbers. Strength of the hand and wrist flexors, shoulders and upper limbs has gained much attention in the scientific literature, and it has been suggested that both general and specific strength training should be part of a climber`s training program. Furthermore, the ability to generate sub-maximal force in different work-rest ratios has proved useful, in examining finger flexor endurance capacity while trying to mimic real-world climbing demands. Importantly, fingers and shoulders are the most frequent injury locations in climbing. Due to the high mechanical stress and load on the finger flexors, fingerboard and campus board training should be limited in lower-graded climbers. Coaches should address, acknowledge, and screen for amenorrhea and disordered eating in climbers. Conclusion Structured low-volume high-resistance training, twice per week hanging from small ledges or a fingerboard, is a feasible approach for climbers. The current injury prevention training aims to increase the level of performance through building tolerance to performance-relevant load exposure and promoting this approach in the climbing field.

This study aimed to assess physical activity levels during 3 school days among first cycle students and its relationship with lower limb muscle strength. Twenty-eight students from the Governor of Muscat were participated in this study, (age: 11.8±0.3 years, height: 9.0±148 cm, mass Body: 14.5±34.8 kg, BMI: 5.3±19.2 kg.m-2 To assess physical activity levels, the ActiGraph GT3X device was used for 3 school days during the week (from 8:00 am to 12:00 pm, daily). All participating performed two tests of lower limb muscle strength (CMJ - FCM). Study results showed that the average physical activity levels of students during 3 school days were (455.9± 56.7minutes) and (26.3±6.6 minutes) for both sedentary physical behavior (SPA) and high-intensity physical activity (VPA), respectively. The results also revealed that the level of moderate and vigorous physical activity level (MVPA) during 3 days of school reached (67.9 ±17.01minutes), which is approximately (22.6 minutes per day), meaning that there was a noticeable decrease in the levels of physical activity practiced during school days (3 days). per week for first cycle students. The results also showed that there was no relationship between all physical activity levels (SPA, LPA, MPA, VPA, MVPA) and lower limb muscle strength tests (CMJ - FCM) among the students (0.05

This study aimed to assess physical activity levels during 3 school days among first cycle students and its relationship with lower limb muscle strength. Twenty-eight students from the Governor of Muscat were participated in this study, (age: 11.8±0.3 years, height: 9.0±148 cm, mass Body: 14.5±34.8 kg, BMI: 5.3±19.2 kg.m-2 To assess physical activity levels, the ActiGraph GT3X device was used for 3 school days during the week (from 8:00 am to 12:00 pm, daily). All participating performed two tests of lower limb muscle strength (CMJ - FCM). Study results showed that the average physical activity levels of students during 3 school days were (455.9± 56.7minutes) and (26.3±6.6 minutes) for both sedentary physical behavior (SPA) and high-intensity physical activity (VPA), respectively. The results also revealed that the level of moderate and vigorous physical activity level (MVPA) during 3 days of school reached (67.9 ±17.01minutes), which is approximately (22.6 minutes per day), meaning that there was a noticeable decrease in the levels of physical activity practiced during school days (3 days). per week for first cycle students. The results also showed that there was no relationship between all physical activity levels (SPA, LPA, MPA, VPA, MVPA) and lower limb muscle strength tests (CMJ - FCM) among the students (0.05

Purpose: The aim of this study was to examine the predictors of change of direction (COD) in highly trained/national level male basketball players using field assessments. Methods: Eight professional male basketball players (age: 24.0 ± 5.5 years; body mass index (BMI): 24.1 ± 1.6 kg m-2) volunteered for participation in this study. All the evaluations were carried out during 2 sessions as follows: First day_1) body composition, 2) unilateral and bilateral squat jump (SJ) and countermovement (CMJ), and 3) Yo-Yo intermittent recovery test level 1 (Yo-Yo IR1); Second day_1) COD performance, and 2) one repetition maximum (1RM) hang clean (HC) and bench press (BP). A linear regression was performed to evaluate the determinants of COD amongst all other measured variables. Furthermore, we applied Pearson correlation coefficient and in the case of non-normally distributed variables, Spearman’s correlation coefficient for the selected variables. Results: The linear regression indicated that only SJ height was a significant determinant of COD (R2 = 58.8%, p = 0.016). Significant correlations were identified between COD test and SJ (r = -0.75, p = 0.034; very large), and relative HC 1 RM (r = -0.74, p = 0.038; very large). Conclusions: The associations found between COD performance and physical parameters should be considered when developing athletic conditioning programs. Especially, the vertical jump heigh could explain the greatest variability in COD performance..

Copyright of Retos: Nuevas Perspectivas de Educación Física, Deporte y Recreación is the property of Federacion Espanola de Asociaciones de Docentes de Educacion Fisica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Study purpose. This study aimed at investigating the anthropometric and physiological characteristics that affect soccer skills in advanced-level youth soccer players. Materials and methods. Ninety advanced youth male soccer players from the U-18 division 1 soccer club were enrolled to participate in this study. The participants were classified into three different positions: defenders, midfielders, and forwards. The anthropometric profiles (height, weight, and body fat) and physiological variables (Y-balance test, Yo-Yo Intermittent Recovery Test Level 1, running-based anaerobic sprint test, sit-up test, countermovement jump test, drop jump test, arrowhead agility test, and 40-m sprint test) were assessed. Soccerspecific skills were measured using the Loughborough soccer passing and shooting protocol. Results. The multiple regression analysis revealed a statistically significant relationship between physical factors and the Loughborough soccer passing ability (R2 = 0.291, F(15, 74) = 2.200, p = 0.015). The results indicated that the relative maximum power displayed the strongest association with passing ability, followed by sit-up, countermovement jump without and with arm swing, and fatigue index. Concerning the shooting performance, the predictors accounted for 21.8% of the variance, with sit-up being the sole significant predictor among other factors. Conclusions. Our findings underscore the significance of relative maximum power, fatigue tolerance, muscular power, and core strength as valuable predictors for enhancing passing ability. In addition, abdominal strength emerged as a crucial indicator of shooting performance. Soccer coaches could use the essential information described in this study for talent identification purposes. [ABSTRACT FROM AUTHOR]

Background: With the emergence of the COVID-19 pandemic, many countries implemented policies that included movement restrictions, social distancing and school closures in order to control the spread of the virus. Even though these actions may have been necessary to save lives, there have been some unintended consequences that could affect future public health. Methods: The present study uses data from more than 24,500 Austrian elementary school children (51.2% male) that participated in a state-wide fitness evaluation program, which was initiated in the 2016/17 school year. In addition to body weight and height, data on cardiorespiratory endurance, muscular power, speed, agility, flexibility and object control were collected from three cohorts prior to the implementation of movement restrictions (school years: 2016/17, 2017/18, 2018/19) and one cohort in 2022, after the majority of COVID-19 policies had been lifted. Results: Body mass index percentiles were significantly higher in children post-COVID-19 (p < 0.01). Further, cardiorespiratory endurance, agility and flexibility were significantly lower post-COVID-19 compared to the years preceding movement restrictions (p ≤ 0.01), while absolute muscular strength was higher in the year 2022 (p < 0.01). Conclusion: Given the detrimental effects of COVID-19 policies on physical fitness in children, additional efforts are necessary that include versatile opportunities for physical activity and the promotion of physical fitness in order to modify the observed negative health trajectories and ensure future public health.

Background: North American indigenous populations experience higher rates of obesity and chronic disease compared with nonindigenous populations. Improvements in musculoskeletal fitness can mitigate negative health outcomes, but is not well understood among indigenous populations. This review examines musculoskeletal fitness measures among North American indigenous populations. Methods: A total of 1632 citations were evaluated and 18 studies were included. Results: Comparisons of musculoskeletal fitness measures between North American indigenous men and boys and women and girls were generally not reported. The greatest left and right combined maximal grip strength and maximal leg strength among Inuit boys and men and girls and women were observed among 20-29 years age group. Maximal combined right and left grip strength declined from 1970 to 1990, by an average of 15% among adults and 10% among youth. Maximal leg extension among Inuit has declined even further, averaging 38% among adults and 27% among youth from 1970 to 1990. Inuit men demonstrate greater grip strength and lower leg strength than Russian indigenous men, whereas Inuit women demonstrate greater leg strength. Conclusions: Further research is needed to better understand physical fitness among indigenous peoples and the potential for improving health and reducing chronic disease risk for indigenous peoples through physical fitness. [ABSTRACT FROM AUTHOR]

Study purpose. This study aimed at investigating the anthropometric and physiological characteristics that affect soccer skills in advanced-level youth soccer players. Materials and methods. Ninety advanced youth male soccer players from the U-18 division 1 soccer club were enrolled to participate in this study. The participants were classified into three different positions: defenders, midfielders, and forwards. The anthropometric profiles (height, weight, and body fat) and physiological variables (Y-balance test, Yo-Yo Intermittent Recovery Test Level 1, running-based anaerobic sprint test, sit-up test, countermovement jump test, drop jump test, arrowhead agility test, and 40-m sprint test) were assessed. Soccer-specific skills were measured using the Loughborough soccer passing and shooting protocol. Results. The multiple regression analysis revealed a statistically significant relationship between physical factors and the Loughborough soccer passing ability (R2 = 0.291, F(15, 74) = 2.200, p = 0.015). The results indicated that the relative maximum power displayed the strongest association with passing ability, followed by sit-up, countermovement jump without and with arm swing, and fatigue index. Concerning the shooting performance, the predictors accounted for 21.8% of the variance, with sit-up being the sole significant predictor among other factors. Conclusions. Our findings underscore the significance of relative maximum power, fatigue tolerance, muscular power, and core strength as valuable predictors for enhancing passing ability. In addition, abdominal strength emerged as a crucial indicator of shooting performance. Soccer coaches could use the essential information described in this study for talent identification purposes.

This study compared cardiorespiratory fitness, bio-motor abilities, and body composition indexes of sprint kayakers categorized into three different age groups and two expertise levels of international- and club-level athletes. Seventy-three male juniors (n = 14, age = 16.2 ± 0.8), under 23 [U23 (n = 15, age = 20.2 ± 1.6)], professionals (n = 16, age = 27.1 ± 4.8), club-level (n = 15, age = 26.9 ± 6.6), and international-level (n = 13, age = 27.3 ± 3.2) sprint kayakers were studied. Cardiorespiratory fitness (assessed using incremental exercise test), 500 and 1,000-m paddling performance (assessed using kayak ergometer), upper-body power (assessed using 30 s all-out Wingate test) and strength (assessed through one repetition tests for bench press, cable row, and prone bench pull exercises), as well as body composition indexes (measured using dualenergy X-ray absorptiometry) were evaluated on four occasions separated by 48 h recovery. U23 and, especially, professionals indicated significantly (p < 0.05) greater outcomes for the majority of the cardiorespiratory fitness parameters [maximal oxygen uptake (VO2max), velocity corresponding to VO2max, Oxygen pulse, maximal ventilation, and second ventilatory threshold] and 500 and 1,000- m performance. U23 and professional sprint kayakers significantly (p < 0.05) differed in the first ventilatory threshold and 500, and 1,000-m performance but not in VO2max or the second ventilatory threshold. Professionals also showed a lower fat mass, higher muscle mass, and higher strength (bench press, prone bench pull, and seated cable row) and power than U23 and junior kayakers. Strength and power indicators had significantly greater values in U23 athletes compared to juniors. International-level athletes also showed superior VO2max, velocity corresponding to VO2max, middle (500-m), and long-distance (1,000-m) time trial performance, strength and power, lower fat, and higher muscle mass than club-level sprint kayakers. Cardiorespiratory fitness (particularly ventilatory threshold), body composition, and muscle strength/power are the best differentiating factors for sprint kayakers of different ages and expertise levels. These findings could aid coaches in prescribing training programs focusing on improving determining factors in paddling performance, as well as in predicting performance and identifying talent. [ABSTRACT FROM AUTHOR]

Aim: Dietary supplementation with inorganic nitrate (NO3-) may enhance exercise performance by improving skeletal muscle contractility and metabolism. CrossFit also, is recognized as a new method improves exercise performance but the interaction effects of nitrate supplements and CrossFit on exercise performance are not well known. The present study was done to examine the interaction effects of CrossFit training and beetroot loading on exercise performances in young inactive men. Methods: In this quasi study, twenty inactive men (aged 21-30 years old), were randomly divided into beetroot juice + CrossFit group (n = 10) or placebo + CrossFitt group (n = 10). All participants were performed CrossFit training 3 days a week for 8 weeks. At the end week of the intervention, supplement group received 140 mL beetroot juice containing about 800 mg of NO3 - per day. Exercise performances were evaluated before and after the intervention. Independent and paired sample t-test were used for data analysis and statistical analyses was set at P≤0.05. Results: The results demonstrated that sprint (14.8% vs. 15.5%), anaerobic power (55.7% vs. 75.5%), fatigue index (67.2% vs. 71.5%) and vertical jump test (12.7% vs. 17.8%) were improved in the both groups (P<0.05), however no significant differences were observed between two groups. Peak aerobic power was increased in the both groups (P<0.05), while the increase of peak aerobic power was higher in the supplement group compare to the placebo group (17.9% vs. 13.3%; P<0.05). Conclusion: Generally, we can conclude that CrossFit training caused improves exercise performance but the interaction of beetroot juice and CrossFit cannot enhance these performances. [ABSTRACT FROM AUTHOR]

Copyright of Health Sport Rehabilitation is the property of H.S. Skovoroda Kharkiv National Pedagogical University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Maximal force can be expressed across a range of conditions influenced by the external load and the time available to express force. As a result, several distinct and specific strength qualities exist. Conversely, some expressions of maximal force are similar and can be categorized as a single quality. Therefore, strength assessment systems must be sophisticated enough to isolate and measure each quality while minimizing redundant information. This article presents a contemporary, evidence-based and practical framework that reduces the many strength and speed-strength metrics into 5 distinct qualities. Alongside this, we present case examples of the application of strength diagnosis. [ABSTRACT FROM AUTHOR]

Background: With the emergence of the COVID-19 pandemic, many countries implemented policies that included movement restrictions, social distancing and school closures in order to control the spread of the virus. Even though these actions may have been necessary to save lives, there have been some unintended consequences that could affect future public health. Methods: The present study uses data from more than 24,500 Austrian elementary school children (51.2% male) that participated in a state-wide fitness evaluation program, which was initiated in the 2016/17 school year. In addition to body weight and height, data on cardiorespiratory endurance, muscular power, speed, agility, flexibility and object control were collected from three cohorts prior to the implementation of movement restrictions (school years: 2016/17, 2017/18, 2018/19) and one cohort in 2022, after the majority of COVID-19 policies had been lifted. Results: Body mass index percentiles were significantly higher in children post-COVID-19 (p < 0.01). Further, cardiorespiratory endurance, agility and flexibility were significantly lower post-COVID-19 compared to the years preceding movement restrictions (p ≤ 0.01), while absolute muscular strength was higher in the year 2022 (p < 0.01). Conclusion: Given the detrimental effects of COVID-19 policies on physical fitness in children, additional efforts are necessary that include versatile opportunities for physical activity and the promotion of physical fitness in order to modify the observed negative health trajectories and ensure future public health. [ABSTRACT FROM AUTHOR]

Topical application of menthol to the skin improves perception (i.e., makes subjects feel cooler) and changes submaximal neuromuscular recruitment facilitating force generation. We explored the effect of menthol (0.2% concentration; sprayed on the legs), on perception and maximal, dynamic (DLT) and isometric (IMLT) (weight) lifting tasks. Nine resistance-trained male subjects (mean ± SD: 24 ± 5 years; 75.7 ± 8.8 kg; 174 ± 10 cm; 5 repetition maximum deadlift [5RM] 132.3 ± 28.5 kg) were tested using a repeated measures design; we hypothesized that performance would improve. Before completing the DLT (i.e., deadlift performance 75% 1RM) and a midthigh pull dynamometer IMLT, subjects were sprayed with (~125 ml) of menthol or control spray. Performance, electromyography (root mean squared [rmsEMG], rectus femoris [RF], biceps femoris [BF], and medial gastrocnemius [MG]), perceptions (leg thermal sensation [TSlegs] and comfort [TClegs] and perceived exertion [RPE] and readiness to train), heart rate, and skin temperature were measured. Data were compared using analysis of variance (effect size ηp²) and t test to a 0.05 alpha level supported by Bayesian analysis. Dynamic lifting task performance was unchanged, although BF rmsEMG was higher (i.e., greater muscle activation in final [10th] repetition). Isometric lifting task force production was higher in the menthol spray (148 ± 30 kgf) condition (control spray 140 ± 30 kgf; p = 0.035, ηp² = 0.444) with corresponding higher rmsEMG (BF 3.8 ± 1.46 vs. control spray 2.9 ± 0.34 V; p = 0.049, ηp² = 0.403). TSlegs was lower after menthol spray before IMLT; subjects felt slightly cool. Menthol spray enhances isometric weightlifting performance with corresponding changes in neuromuscular activity, partially supporting our hypothesis. [ABSTRACT FROM AUTHOR]

This study compared inter-individual variability in the adaptive responses of cardiorespiratory fitness, anaerobic power, and motor abilities of male volleyball players to high-intensity interval training (HIIT) prescribed as repetitive drop jumps (interval jumping) and running-based intervals (interval running). Twenty-four collegiate volleyball players were equally randomized to two training groups executing 11 minutes of interval running or interval jumping during which they ran or repeated drop-jumps for 15 seconds, alternating with 15 seconds of passive recovery. Before and after the 6-week training period, aerobic fitness, cardiac function, and anaerobic power were evaluated using a graded exercise test, impedance cardiography, and a lower-body Wingate test, respectively. Additionally, linear speed, agility, and jumping tests determined motor abilities. Both interventions significantly enhanced maximum oxygen uptake (V̇O 2max ), velocity associated with V̇O 2max , first and second ventilatory thresholds (VT 1 & VT 2 ), maximal cardiac output (Q̇ max ), stroke volume (SV max ), peak and average power output, vertical jump, change of direction, and linear sprint speed. Interval jumping group demonstrated a significantly greater improvement in squat jump ( p = 0.001; 95% CI: 2.51-5.42) and countermovement jump ( p = 0.001; 95% CI: 2.11-4.61) compared to interval running group. Conversely, interval running group elicited a greater enhancement in sprint speed ( p = 0.002; 95% CI: 2.53-5.71) than interval jumping group. Examining the individual residual in the adaptive responses revealed that interval running induced more homogenized adaptations across individuals in VT 1 ( p = 0.04; 95% CI: 0.03-1.33), Q̇ max ( p = 0.03; 95% CI: 0.04-1.64), SV max ( p = 0.04; 95% CI: 0.02-1.75), and maximal sprint speed ( p = 0.01; 95% CI: 0.72-1.95) in contrast to interval jumping. However, the uniformity of adaptations in countermovement jump in response to interval jumping surpassed that of interval running ( p = 0.02; 95% CI: 0.08-1.32). Although both training modalities effectively improved the mentioned variables concurrently, tailoring the HIIT intervention to the reference intensity and training modality specific for each quality may enhance measured quality., (© Journal of Sports Science and Medicine.)

Inorganic nitrate ([Formula: see text]) supplementation increases nitric oxide (NO) bioavailability and may improve muscular power and endurance, although most studies are in males. Therefore, the present double-blind, randomized, placebo-controlled study examined the effects of [Formula: see text] supplementation on isokinetic peak power, maximal voluntary isometric contraction (MVIC) force, muscular endurance (time-to-task failure; TTF), and recovery from fatigue in young females ( n = 12) and males ( n = 14). Participants consumed ∼13 mmol [Formula: see text] [beetroot juice (BRJ)], or an identical [Formula: see text]-depleted beverage placebo (PL), for ∼3 days and 2 h before testing visits. Plasma nitrate and nitrite were elevated in the BRJ condition ( P ≤ 0.05). Peak power (W·kg -1 ) showed a sex effect ( P ≤ 0.05) at all angular velocities and a sex-by-treatment effect at 270 and 360°/s ( P ≤ 0.05). Post hoc analysis revealed no significant differences between treatments ( P > 0.05). Estimated maximal knee extension power ( P max ) and maximal knee extension velocity ( V max ) demonstrated no sex, treatment, or sex-by-treatment effect ( P > 0.05). There were no significant effects for TTF (F: PL; 269 ± 161 vs. BRJ; 277 ± 158 s and M: PL; 228 ± 171 vs. BRJ; 194 ± 100 s; P > 0.05). Cohen's d effect sizes for peak power showed moderate to large effect sizes at 270 ( d = 0.92) and 360°/s ( d = 0.81), showing a possible differentiated effect of dietary nitrate in females and males. The present data indicate that [Formula: see text] supplementation does not significantly affect knee extensor maximal power, maximal contraction velocity, and muscular endurance in either sex. The sex-dependent response to dietary nitrate supplementation requires further investigation as data on females is scarce. NEW & NOTEWORTHY Recent data have suggested that inorganic nitrate ([Formula: see text]) supplementation may benefit males; however, females may experience worsened endurance capacity. This study revealed a potential differentiated effect of [Formula: see text] supplementation on outcomes of muscle contractile function between healthy, young males and females. The specific responses of [Formula: see text] supplementation in females and across sexes remain understudied and require further investigation.

Oral inorganic nitrate ([Formula: see text]) supplementation increases nitric oxide (NO) bioavailability and may improve muscular power in males and females, although data in females are limited. Estrogen increases NO bioavailability and fluctuates throughout the menstrual cycle, with low levels in the early follicular (EF) phase and peaking during the late follicular (LF) phase. The purpose of the present study was to examine the effects of [Formula: see text] supplementation on isokinetic peak power, maximal voluntary isometric contraction (MVIC) force, muscular endurance, and recovery from fatigue in healthy young females during the EF and LF phases of the menstrual cycle. Ten eumenorrheic females were tested in a double-blinded, randomized, placebo-controlled design. Participants consumed ∼13 mmol [Formula: see text], in the form of 140 mL beetroot juice (BRJ), or an identical [Formula: see text]-depleted placebo (PL), for ∼5 days prior to visits and 2 h prior to testing. Plasma estradiol was elevated in the LF phase, and plasma nitrite and nitrate were elevated in the BRJ condition ( P < 0.05). Although isokinetic peak power was unchanged, calculated maximal power (Pmax) and maximal velocity (Vmax) were significantly worsened in the BRJ treatment independent of the menstrual cycle phase ( P = 0.02 and 0.03, respectively). Muscular endurance, MVIC, and fatigue recovery were unaltered by BRJ or the menstrual cycle. These data indicate that [Formula: see text] supplementation decreased maximal power and velocity in females and suggest that the benefits of [Formula: see text] supplementation previously found in males may not extend to young females. NEW & NOTEWORTHY Recent data have suggested that inorganic nitrate ([Formula: see text]) supplementation may benefit males, however, females may experience worsened endurance capacity independent of menstrual cycle phase. This study revealed neither [Formula: see text] supplementation nor the follicular phase of the menstrual cycle influenced maximal isometric voluntary contraction or endurance capacity in healthy, young, naturally menstruating females, whereas [Formula: see text] supplementation significantly worsened estimated peak power (Pmax) and velocity (Vmax) independent of the menstrual cycle phase.

Background: Ageing affects metabolic flexibility, although physical status could influence this relationship. This cross-sectional study aims to describe and analyse the metabolic flexibility/inflexibility in a group of active older women, together with the impact of ageing and physical status on their oxidation rates and maximal fat oxidation (MFO). Methods: Fifteen volunteers (69.00 ± 6.97 years)—from 24 women—completed an incremental cycling test until the second ventilatory threshold. Intensity increased 10 W each 3 min 15 s, starting at 30 W. Gas exchange, heart rate, rate of perceived effort, pain scale and muscle power were registered, together with lactate. VO2 and VCO2 were considered for fat and carbohydrate oxidation (FATox and CHOox; Frayn's equation) at intensities 60%, 80% and 100% from the peak power in the test (P100). Psychophysiological parameters were compared at MFO/FATmax and P100, together with the energy expenditure calculations around MFO (included FAT and CHO contributions), and the main correlation analyses, with and without P100 and VO2 as covariates. Results: FATox was low at MFO (0.13; 95% CI [0.09–0.17] mg/min/kgFFM; 3.50; 95% CI [2.49–4.50] mg/min/kgFFM), with short oxidation-rate curves shifting down and leftward. CHOox and FATox were both low for reduced power with age (77.14 ± 18.58 W and 39.29 ± 9.17 W at P100 and MFO, respectively), all accompanied by a fall in energy expenditure (5.44 ± 2.58 kcal/min and 3.32 ± 1.55 kcal/min at P100 and MFO, respectively). Power appears as a determinant factor, given its strong and negative significant association with age (r = − 0.85, p < 0.005; R2 = 0.72) and moderate with MFO (r = − 0.54, p = 0.04; R2 = 0.29). In turn, energy expenditure shows a positive and moderate association with muscle power (r = 52, p = 0.04). Conclusions: Despite the drop in substrates oxidation with age, physical status (i.e. larger muscular power and energy expenditure) suggests a key role in the preservation of metabolic health with ageing in active women. [ABSTRACT FROM AUTHOR]

Age-groups are commonly implemented in education and sports in order to provide fair and equal opportunities. Various studies, however, have shown a competitive advantage for early born children over their relatively younger peers, which is referred to as relative age effect. The present study examined differences in various components of physical fitness in Austrian elementary-school children. A total of 18,168 children (51% boys) between 6 and 11 years of age provided valid data on anthropometric characteristics and physical fitness. Specifically, children completed eight fitness tests that assessed cardiorespiratory endurance, muscular strength and power, speed, agility, flexibility and object control. Across age-specific quartiles, older children were significantly taller and heavier than their younger peers. Older children also displayed better performance for strength and power, speed, agility and object control, while differences in cardio-respiratory endurance were less pronounced. These results highlight the presence of a relative age effect during the elementary school years and emphasize the need to consider individual differences in the evaluation of children’s performance. As all children should be given equal opportunities to engage successfully in physical education and sports, physical education teachers and youth coaches need to be educated on the implications of a relative age effect.

Introduction: In recent years, music has been used as an ergogenic aid in different sports, especially in the training of muscular strength. Objetive: Determinate the ergogenic effect of music on the performance of muscle strength. Method: A systematic review was carried out under the PRISMA guidelines, for which the following Web of Science, Pubmed and Ebsco database were searched as well as Google Schoolar. The terms music AND muscular strength were used. 1975 papers were identified in the database from which 12 were selected that met the inclusion criteria, one more that was found in Google Scholar to include a total of 13 articles in this study. Results: In three articles muscular power was evaluated in wich all of them were improved with music. Also in seven studies the maximum strength was assessed in wichin which two presentes positive results. Finally, muscula endurance was evaluated in eigth articles, of which seven were positively influenced by music. Conclusion: Music has ergogenic effects on muscular endurance, but no on maximum strength. [ABSTRACT FROM AUTHOR]

Objective: Existing isokinetic contractions are characterized using standardized angular velocities, which can induce differing adaptations. Here, we characterized the variation in the isokinetic parameters of knee extensors according to individualized angular velocity (IAV)., Methods: We performed a cross-sectional study of 19 young, healthy men. We measured the maximum angular velocity (MAV) of concentric knee extension using the isotonic mode of an isokinetic dynamometer. Isometric and isokinetic (at angular velocities corresponding to 100%, 70%, 40%, and 10% of each individual's MAV) knee extensor contractions were performed, and the peak torque and mean power were recorded., Results: Peak torque significantly decreased with increasing IAV (129.42 ± 25.04, 84.37 ± 20.97, and 56.42 ± 16.18 Nm at 40%, 70%, and 100%, respectively), except for isometric contraction (233.36 ± 47.85) and at 10% of MAV (208 ± 48.55). At the mean power, 10% of MAV (74.52 ± 20.84 W) was significantly lower than the faster IAV (176.32 ± 49.64, 161.53 ± 56.55, and 145.95 ± 50.64 W at 40%, 70%, and 100%, respectively), and 100% was significantly lower than 40%., Conclusion: The optimized IAV for isokinetic contraction to improve power output while maintaining torque is 10% to 40% of MAV. IAV may reflect both the velocity and force components of power because individuals do not have the same angular velocity., Competing Interests: Declaration of conflicting interestThe authors declare that there is no conflict of interest.

The purpose of this study was to investigate changes in functional performance such as thermal images of the lower limbs; muscular power and clinical test performed for predict knee mechanics in males and females practitioners of resistance exercise with free-weights. Twenty male and eighteen female practitioners of resistance exercise (RE) with free-weights were recruited for research. All subjects practiced regularly RE 4.8 ± 0.4 days' week-1and total volume of 255.1 ± 9.2 minutes per week. All thermal images were performed in a thermoneutral room with temperature of 21°C with a relative humidity of 65%. Then, all subjects performed three CMJ trials and one min rest between trials. Finally, males and females performed the SLSD test with subjects stood on an 8-inch wooden box, assumed a single-limb stance. The two-way ANOVA yielded main effects for the group in the single leg step down test (SLSD test) (F1.36 = 9.260, p<.004), push-off phase (F1.36 = 27.11, p<.0001) and landing phase (F1.36 = 16.72, p<.0002) showed significant differences (p<.05) between sex. Thermal images showed significant difference only in the mean skin temperature at the posterior left and right leg between males vs. females (p<.05). Pearson's analysis demonstrated that jump height was significantly correlated with SLSD test in males and females. However, male showed negative correlation between skin temperature at the anterior leg and jump height. These finding shown the efficiency thermal images and SLSD test as possible tools to investigate muscle power in males and females that practice RE with free-weights. [ABSTRACT FROM AUTHOR]

Background The fitness levels of Canadian adults declined substantially between 1981 and the years 2007 to 2009, suggesting a reduction in population health. This paper updates the fitness trends of Canadians aged 20 to 69 years by extending the time period to 2017. Data and methods The Canadian Health Measures Survey is a repeated cross-sectional survey that is conducted to produce nationally representative health estimates. Descriptive statistics are presented for fitness measures in 2016 and 2017 by age and sex, and trends in fitness were calculated spanning a period of 10 years (2007 to 2017). The associations between fitness measures and meeting the 2020 Canadian physical activity recommendations were also assessed. Results From 2007 to 2017, there were few statistically significant changes in the fitness levels of Canadian adults. When all ages were combined, there were declining trends in predicted cardiorespiratory fitness, from 39.5 to 36.7 mL•kg-1•min-1 among men and 34.0 to 32.2 mL•kg-1•min-1 among women. Trends indicated declining flexibility among men. In general, meeting the current Canadian moderate-to-vigorous physical activity recommendation was associated with better fitness, particularly in the categories of predicted cardiorespiratory fitness and body composition. Interpretation The periodic assessment of fitness in Canadians provides valuable insight into population health. The present update provides evidence that fitness levels among adults have generally stabilized over the past 10 years. Taken with the reported declines in fitness that occurred from 1981 to the 2007-to-2009 period, this study shows that the fitness of Canadian adults remained low between 2007 to 2009 and 2016 to 2017. It is necessary to explore new ways to help improve the fitness levels of the Canadian population. [ABSTRACT FROM AUTHOR]

Maximal muscular power production is of fundamental importance to human functional capacity and feats of performance. Here, we present a synthesis of literature pertaining to physiological systems that limit maximal muscular power during cyclic actions characteristic of locomotor behaviours, and how they adapt to training. Maximal, cyclic muscular power is known to be the main determinant of sprint cycling performance, and therefore we present this synthesis in the context of sprint cycling. Cyclical power is interactively constrained by force-velocity properties (i.e. maximum force and maximum shortening velocity), activation-relaxation kinetics and muscle coordination across the continuum of cycle frequencies, with the relative influence of each factor being frequency dependent. Muscle cross-sectional area and fibre composition appear to be the most prominent properties influencing maximal muscular power and the power-frequency relationship. Due to the role of muscle fibre composition in determining maximum shortening velocity and activation-relaxation kinetics, it remains unclear how improvable these properties are with training. Increases in maximal muscular power may therefore arise primarily from improvements in maximum force production and neuromuscular coordination via appropriate training. Because maximal efforts may need to be sustained for ~15-60 s within sprint cycling competition, the ability to attenuate fatigue-related power loss is also critical to performance. Within this context, the fatigued state is characterised by impairments in force-velocity properties and activation-relaxation kinetics. A suppression and leftward shift of the power-frequency relationship is subsequently observed. It is not clear if rates of power loss can be improved with training, even in the presence adaptations associated with fatigue-resistance. Increasing maximum power may be most efficacious for improving sustained power during brief maximal efforts, although the inclusion of sprint interval training likely remains beneficial. Therefore, evidence from sprint cycling indicates that brief maximal muscular power production under cyclical conditions can be readily improved via appropriate training, with direct implications for sprint cycling as well as other athletic and health-related pursuits. [ABSTRACT FROM AUTHOR]

This study compares the effects of 2 high-intensity interval training (HIIT) configurations, a 10-5 vs. a 20-10 second work-to-rest ratio, on anaerobic and aerobic performance. Thirty-four individuals were randomly assigned to 10-5-HIIT (n =17) and 20-10-HIIT (n =17) groups to complete 6 cycles of 6 exercises, 3 days a week for 4 weeks. The 10-5-HIIT was performed with 10 s:5 s work-to-rest ratio with 1-minute recovery between cycles, while the 20-10-HIIT was performed with 20 s:10 s work-to-rest ratio followed by a 2-minute recovery. Anaerobic (i.e., peak power [PP], anaerobic capacity [AC], anaerobic power [AP], and total work [TW]) and aerobic fitness (i.e., time to exhaustion [TE], absolute VO2max [A-VO2max], relative VO2max [R-VO2max]) were measured with pre-training and post-training intervention. A significant main effect time was observed for both 10-5-HIIT and 20-10-HIIT (p < 0.05) in PP (9.2%, 5.7%); AC (14.9%, 8.6%); AP (9.0%, 6.2%); TW (15.1%, 8.5%); TE (4.3%, 5.5%); A-VO2max (9.4%, 8.9%); R-VO2max (8.5%, 8.2%), respectively. In conclusion, individuals may be able to achieve similar health benefits as 20-10-HIIT by performing 10-5-HIIT, despite exercising for 50% less total time. High-intensity interval training has been suggested as a "time-efficient" mode of exercise that can mitigate the most significant barrier to physical activity, "lack of time." Both 10-5-HIIT and 20-1 0-HIIT can induce performance adaptations to a similar extent. However, because of shorter time commitment, performing 10-5-HIIT at 10 s:5 s work-to-rest ratio may offer a shorter and equally efficient interval. Functional fitness training during HIIT protocols seems to be as beneficial as ergometer-based HIIT to improve anaerobic and aerobic performance. [ABSTRACT FROM AUTHOR]

Background/objective: The aim of this study was to examine differences in bar velocity between the cambered and standard barbell bench press exercise. Methods: Ten healthy men volunteered for the study (age = 27.9 ± 3.7 years; body mass = 89.6 ± 11.7 kg; experience in resistance training 5.7 ± 2.1 years; bench press one-repetition maximum > 120% body mass). The first session aiming at the determination of the one-repetition maximum was followed by two experimental sessions consisted of performing 3 sets of 3 repetitions of the bench press exercise with the cambered or standard barbell at 50% of one-repetition maximum (of the standard barbell) in randomized order. Results: The two-way repeated measures ANOVA indicated a significant main effect of bar type on mean velocity (p=0.001; η²=0.739) and peak velocity (p=0.002; η²=0.661). The post-hoc analysis showed a significantly higher mean velocity for the cambered barbell compared to the standard barbell bench press in Set 1 (p=0.002) and Set 2 (p=0.012), but not in Set 3 (p=0.062). Moreover, there was a significantly higher mean velocity in Set 2, than in Set 1 (p=0.017) during the standard barbell bench press, with no other differences. Furthermore, a significantly higher peak velocity for the cambered barbell in comparison to the standard barbell was observed in all sets of the BP exercise (p<0.001; p=0.014; p=0.048; respectively). Conclusions: The outcomes of this investigation indicated that the cambered barbell used during the bench press training session significantly increases bar velocity compared to the standard barbell with the same external load across the workout. [ABSTRACT FROM AUTHOR]

Age-groups are commonly implemented in education and sports in order to provide fair and equal opportunities. Various studies, however, have shown a competitive advantage for early born children over their relatively younger peers, which is referred to as relative age effect. The present study examined differences in various components of physical fitness in Austrian elementaryschool children. A total of 18,168 children (51% boys) between 6 and 11 years of age provided valid data on anthropometric characteristics and physical fitness. Specifically, children completed eight fitness tests that assessed cardiorespiratory endurance, muscular strength and power, speed, agility, flexibility and object control. Across age-specific quartiles, older children were significantly taller and heavier than their younger peers. Older children also displayed better performance for strength and power, speed, agility and object control, while differences in cardio-respiratory endurance were less pronounced. These results highlight the presence of a relative age effect during the elementary school years and emphasize the need to consider individual differences in the evaluation of children’s performance. As all children should be given equal opportunities to engage successfully in physical education and sports, physical education teachers and youth coaches need to be educated on the implications of a relative age effect. [ABSTRACT FROM AUTHOR]

This study aimed to compare the aerobic power (treadmill running) and muscle power (bench press and bench pull) of Junior/U23 paddlers from Slovakia who won medals in international championships with that of those who did not take the podium. Forty-three Slovak Junior/U23 paddlers (sprint = 24, medalists = 8, non-medalists = 16; slalom = 19, medalists = 11, non-medalists = 8) were tested in 2018 and 2019 after the world championships. The maximal oxygen uptake (VO2max) and the velocity at maximal oxygen uptake (vVO2max) were determined by the incremental running protocol (0% slope and 1 km⋅h–1 increments every minute until volitional exhaustion). Mean maximal power from the entire concentric phase was recorded during bench press and bench pull exercises by the validated TENDO weightlifting analyzer. No interaction was obtained between medal and canoe discipline for VO2max (p = 0.069, F = 3.495), vVO2max (p = 0.552, F = 0.361) and absolute (bench press: p = 0.486, F = 0.495; bench pull: p = 0.429, F = 0.640) or relative (bench press: p = 0.767, F = 0.089; bench pull: p = 0.696, F = 0.155) mean maximal power. Conversely, a significant effect for the medal on the bench press (absolute p = 0.017, F = 6.170; relative p = 0.043, F = 4.384) and the bench pull (absolute p = 0.041, F = 4.470) mean maximal power were observed. Our study indicates the absolute mean power on the bench press as a prerequisite for success in international Junior/U23 championships of slalom and sprint canoeing. However, the mean power on bench pull seems to have a deeper influence on sprint paddlers when compared to slalom athletes. Regarding the aerobic power, the data from the treadmill testing did not reveal outcomes between medalists and non-medalists. This result can be associated with the lack of specificity of the incremental treadmill testing for canoeing, and future studies are encouraged to propose specific protocols to compare the aerobic power of medalists and non-medalists in international slalom and sprint championships.

Krčmár, M, Krčmárová, B, Bakaľár, I, and Šimonek, J. Acute performance enhancement after squats combined with elastic bands on short sprint and vertical jump height in female athletes. J Strength Cond Res 35(2): 318–324, 2021—The main purpose of this study was to compare back squats with and without elastic bands on sprint and vertical jump height. Fourteen female athletes (21.9 ± 2.3 years; 177.5 ± 6.36 cm; 66.2 ± 6.2 kg; 1 repetition maximum [1RM]/ body mass: 1.96 ± 0.14) agreed to participate. On 4 separate days, athletes walked freely for 5 minutes (CON), performed 3 sets of 4 repetitions at 85% of their 1RM with 20% or 30% (BAND20 or BAND30) of the total resistance originated from elastic bands, or performed 3 sets and 4 repetitions at 85% of their 1RM with an isoinertial load (ISO) before performance tests. Posttesting began 5 and 10 minutes after the last set of squats and included sprints over 3, 5, and 10-m, squat jump (SJ), and countermovement (CMJ) vertical jump height. The results of this study show that all postactivation performance enhancement (PAPE) protocols significantly improved 10-m sprint time (p < 0.05 to p < 0.01). Only BAND30 significantly improved 3-m and 5-m sprint times at both times of posttesting (p < 0.01). Comparison of PAPE protocols showed a significant difference when comparing BAND30 vs. ISO in SJ height in favor of BAND30 only when the best SJ height results from both posttesting times were selected (p < 0.01, g = 1.08). The results of this study suggest that all PAPE protocols were able to enhance short sprints and vertical jump height, but it seems that there is a greater trend to achieve better performance after performing the BAND30 protocol that can be seen by higher effect sizes achieved almost in all tests compared with the other PAPE protocols. [ABSTRACT FROM AUTHOR]

We explored the associations between force-velocity-power (FVP) profiles and inter-limb asymmetries in FVP profiles obtained during unilateral jumping and single-leg isokinetic knee extension and flexion tasks. Thirty (13 senior and 17 junior) basketball players performed unilateral jumps with different levels of unloading (0–40% body mass) and isokinetic knee extension and flexion at different angular velocities (60–300°/s) with each leg. Senior and junior basketball players exhibited similar jump performance, normalized knee extensor and flexor strength, and relatively similar jumping and isokinetic FVP profiles. No significant associations between unilateral jump and isokinetic knee extension and flexion FVP parameters were found (all r ≤ 0.26; p > 0.05). Inter-limb asymmetries had no or very weak associations with unilateral jump height (−0.2 < r < 0.2; all p > 0.1); also, inter-limb asymmetries in jump and isokinetic FVP parameters were generally weakly associated (median r < 0.1). Finally, unilateral jump height was weakly-to-moderately associated with isokinetic F0, jumping Pmax, and normalized knee extension isokinetic peak torque at 60°/s and 240°/s (r = 0.35–0.57). These results suggest that the generalizability of the FVP profile of isolated muscle groups to complex ballistic tasks is weak. [ABSTRACT FROM AUTHOR]

This study aimed to compare the aerobic power (treadmill running) and muscle power (bench press and bench pull) of Junior/U23 paddlers from Slovakia who won medals in international championships with that of those who did not take the podium. Forty-three Slovak Junior/U23 paddlers (sprint = 24, medalists = 8, non-medalists = 16; slalom = 19, medalists = 11, non-medalists = 8) were tested in 2018 and 2019 after the world championships. The maximal oxygen uptake (VO2max) and the velocity at maximal oxygen uptake (vVO2max) were determined by the incremental running protocol (0% slope and 1 km⋅h–1 increments every minute until volitional exhaustion). Mean maximal power from the entire concentric phase was recorded during bench press and bench pull exercises by the validated TENDO weightlifting analyzer. No interaction was obtained between medal and canoe discipline for VO2max (p = 0.069, F = 3.495), vVO2max (p = 0.552, F = 0.361) and absolute (bench press: p = 0.486, F = 0.495; bench pull: p = 0.429, F = 0.640) or relative (bench press: p = 0.767, F = 0.089; bench pull: p = 0.696, F = 0.155) mean maximal power. Conversely, a significant effect for the medal on the bench press (absolute p = 0.017, F = 6.170; relative p = 0.043, F = 4.384) and the bench pull (absolute p = 0.041, F = 4.470) mean maximal power were observed. Our study indicates the absolute mean power on the bench press as a prerequisite for success in international Junior/U23 championships of slalom and sprint canoeing. However, the mean power on bench pull seems to have a deeper influence on sprint paddlers when compared to slalom athletes. Regarding the aerobic power, the data from the treadmill testing did not reveal outcomes between medalists and non-medalists. This result can be associated with the lack of specificity of the incremental treadmill testing for canoeing, and future studies are encouraged to propose specific protocols to compare the aerobic power of medalists and non-medalists in international slalom and sprint championships. [ABSTRACT FROM AUTHOR]

External load influences internal load in resistance training (RT). The purpose of the present study was to compare the total volume-load, perceptual and stress responses during three different RT protocols. Twelve resistance-trained men completed three different RT protocols with the back squat and bench press exercises: (1) power (POW) (5 sets of 6 repetitions at 50%1RM, 2-min of rest), (2) hypertrophy (HYP) (5 sets-to-failure at 75%1RM, 2-min of rest), and (3) strength (STR) (5 sets-to-failure at 90%1RM, 3-min of rest). Volume-load (kg × reps.), session rating of perceived exertion (sRPE), training impulse (TRIMP; reps. × sRPE), cortisol, immunoglobulin A (IgA), lactate, and creatine kinase (CK) were assessed before and/or after the sessions. HYP was the most demanding session in terms of volume-load (p < 0.001), TRIMP (p < 0.001), cortisol (p = 0.001), lactate (p < 0.001), and CK (p = 0.001). Despite POW exhibited a greater volume-load than STR (p = 0.016), the latter exhibiting a greater sRPE (p < 0.001), and a greater post-session CK (p = 0.05). However, the TRIMP of STR and POW were not statistically different (152 vs. 260 AU; p = 0.089). These specific responses could be meditated by the presence of muscular failure. When pooling all the sessions, significant correlations were revealed among external and internal stress markers (r = 0.35–0.80; p ≤ 0.05). The use of TRIMP could be recommended as a simple and valid monitoring tool which integrates into a single parameter the internal and the external loads of RT sessions. [ABSTRACT FROM AUTHOR]

Background The aim of this study was to investigate if choice over resistance training exercise order affects motor performance and psychological outcomes among elite youth hockey players. Methods Seventeen elite hockey players (male, n = 14; female, n = 3, age: 15.1 ± 1.1 years) participated in this study. In the first session, individual optimum power loads were calculated in the back squat, jump squat, bench press and bench throw exercises. Then, in four counterbalanced sessions, participants completed three sets of six repetitions in the same exercises loaded with their optimum power loads. In two sessions, athletes used a self-selected order of exercises, while in other two sessions the order was predetermined. Power outputs were estimated with a linear position transducer. Fatigue and enjoyment were measured during and after the sessions using standardized questionnaires. Repeated measures analyses of variance and a paired-sample t-test were used to compare the effects between conditions. Results We observed trivial to small differences between conditions in power outputs (p ≥ 0.07; ES ≤ 0.21), fatigue (p ≥ 0.42; ES ≤ 0.33) and enjoyment (p = 0.72; ES = 0.05). Conclusion Given the comparable effects between approaches, both can be used when coaching youth athletes. Self-selecting the order of exercises based on preferences is a feasible and practical coaching option when working with youth athletes.

Abstract Aim: To compare two different randori structure (high volume and short pauses - TRAD training vs low volume with long pauses - COMP training) in the neuromuscular and metabolic responses of elite judo athletes. Methods: The first situation (TRAD) consisted of 12 randoris of 5 minutes with 45 seconds rest, and the other situation (COMP), consisted of 6 randoris of 5 minutes with 10 minutes between them. Physiological (Blood Lactate and Creatine Kinase), neuromuscular (Countermovement Jump and Medicine Ball Throws) and perceptive variables (Rating Perceived Exertion) were measured before and at the end of the sessions. Results: The subjective perception of effort at the end of the training was significantly higher in the TRAD training type (TRADpost: 8.1 ± 0.9 AU; COMPpost: 6.6 ± 1.5 AU, p

Growth and maturation affect long term physical performance, making the appraisal of athletic ability difficult. We sought to longitudinally track youth soccer players to assess the developmental trajectory of athletic performance over a 6-year period in an English Premier League academy. Age-specific z-scores were calculated for sprint and jump performance from a sample of male youth soccer players (n = 140). A case study approach was used to analyse the longitudinal curves of the six players with the longest tenure. The trajectories of the sprint times of players 1 and 3 were characterised by a marked difference in respective performance levels up until peak height velocity (PHV) when player 1 achieved a substantial increase in sprint speed and player 3 experienced a large decrease. Player 5 was consistently a better performer than player 2 until PHV when the sprint and jump performance of the former markedly decreased and he was overtaken by the latter. Fluctuations in players' physical performance can occur quickly and in drastic fashion. Coaches must be aware that suppressed, or inflated, performance could be temporary and selection and deselection decisions should not be made based on information gathered over a short time period. [ABSTRACT FROM AUTHOR]

The research aim was to identify the effect of using some plyometric exercises to improve muscular power (vertical jump) and digital achievement in high jump activity among third year's students. The researchers used an experimental method in conformity with research nature between pre-tests and post-tests for the sample research. The sample was formed by students belonging to the physical education and sports institute, University of Mostaganem (Algeria) of the academic year 2018/2019. 40 students were chosen and divided into two groups (experimental 21 students, control 19 students). The vertical jump test of stability and digital achievement test were used. After the treatment of the results by statistical means and through these results, it has been reached several conclusions from them. Plyometric exercises are important to develop vertical jump and digital achievement level in high jump [discussion significant difference (p≤0.05)] among students, and the best improvement of the experimental group based on plyometric exercises is marked comparing to the control group. [ABSTRACT FROM AUTHOR]

Background. The aim of this study was to investigate if choice over resistance training exercise order affects motor performance and psychological outcomes among elite youth hockey players. Methods. Seventeen elite hockey players (male, n = 14; female, n = 3, age: 15.1 ± 1.1 years) participated in this study. In the first session, individual optimum power loads were calculated in the back squat, jump squat, bench press and bench throw exercises. Then, in four counterbalanced sessions, participants completed three sets of six repetitions in the same exercises loaded with their optimum power loads. In two sessions, athletes used a self-selected order of exercises, while in other two sessions the order was predetermined. Power outputs were estimated with a linear position transducer. Fatigue and enjoyment were measured during and after the sessions using standardized questionnaires. Repeated measures analyses of variance and a paired-sample t-test were used to compare the effects between conditions. Results. We observed trivial to small differences between conditions in power outputs (p ≥ 0.07; ES ≤ 0.21), fatigue (p ≥ 0.42; ES ≤ 0.33) and enjoyment (p = 0.72; ES = 0.05). Conclusion. Given the comparable effects between approaches, both can be used when coaching youth athletes. Self-selecting the order of exercises based on preferences is a feasible and practical coaching option when working with youth athletes. [ABSTRACT FROM AUTHOR]

Bringhurst, RF, Wagner, DR, and Schwartz, S. Wingate anaerobic test reliability on the velotron with ice hockey players. J Strength Cond Res 34(6): 1716–1722, 2020— This study evaluated the test-retest reliability of the Wingate Anaerobic Test (WAnT) performed on a Velotron electromagnetically braked cycle ergometer for power-trained athletes and assessed whether a familiarization trial was necessary to achieve high test-retest reliability. Twenty-one male ice hockey players (age 23.5 ± 4.7 years, mass 86.3 ± 16.6 kg, height 180.9 ± 7.4 cm) from a collegiate club team (Club = 10) and a recreational league (Rec = 11) performed three 30-second WAnTs within 2 weeks and with at least 24 hours between visits. Mean power (MP), anaerobic capacity, peak power (PP), anaerobic power, maximum revolutions per minute, and fatigue index were assessed. Resistance was 8.5% of the participant’s body mass. The effect of time on power output was moderated (p < 0.001, h²p = 0.24) such that a significant increase was observed after a practice trial, but not between subsequent trials for the Club players; no practice effect was observed among Rec players. Extremely high reliability (ICC1,1) was found between trials after excluding the practice trial (MP = 0.973, anaerobic capacity = 0.975, PP = 0.957, and anaerobic power = 0.890). Club players achieved higher outputs despite no significant differences in body size or age compared with Rec players. Ice hockey players performing the 30-second WAnT on the Velotron electromagnetically braked cycle ergometer had highly reliable data, and using a familiarization trial is recommended to increase reliability and achieve higher power outputs. [ABSTRACT FROM AUTHOR]

Introduction/Purpose: Muscular power is important in applications ranging from elite sport to activities of daily living. Results for improvements in power after resistance training have been mixed, possibly because of changes in muscle activation and deactivation rates. Our purpose was to determine the effects of heavy and explosive training programs on maximal power across a range of frequencies during cyclical contractions using a mathematical model. Methods: Maximal force production and time constants for muscle activation and deactivation after heavy and explosive training programs were determined using previously reported data. A muscle–tendon model was subjected to sinusoidal length change, and activation and deactivation were set to maximize power for a range of cycle frequencies (0.5–3.0 Hz). Power for shortening/lengthening cycles was modeled for each training program and for a hypothetical periodized program with the best results from each program. Results: The heavy training program increased strength by 26.8%, and increased time required for activation (20%) and deactivation (48%). The explosive training program increased strength by 10.8%, but decreased time required for activation (24%) and deactivation (10%). Increases in maximal power were similar after heavy (13.6%) and explosive (13.8%) training, but with different power–frequency relationships (optimal frequencies of 1.56 and 1.94 Hz for heavy and explosive, respectively). The hypothetical periodized program increased power by 30.3% (optimal frequency at 1.94 Hz). Conclusion: Power during low-frequency movements (e.g., swimming) improved more after heavy training, whereas power during high-frequency movements (e.g., running) improved more after explosive training. These findings suggest that changes in time required for activation and deactivation in response to training are highly influential for maximal power across a range of functional frequencies, ultimately altering the ideal training regimen for specific activities. [ABSTRACT FROM AUTHOR]

Purpose: This study examined the post-activation potentiation effects of body-weight lunge exercises with blood-flow restriction on jump performance. Eighteen anaerobically trained men took part in this study across 3 weeks.Methods: During the first week, participants were familiarised with the lunge exercises with blood-flow restriction and the drop-jump protocol. In the second and third week, participants were randomly allocated to complete body-weight lunges (three sets of eight repetitions) either with or without blood-flow restriction (occlusion set at 130% of systolic blood pressure) to induce post-activation potentiation. Drop-jump performance was assessed between blood-flow conditions, and prior to, and at the third, sixth, ninth, twelfth and fifteenth minute following each lunge exercise. Relationships between mechanical contributors of jump performance and final jump performance were examined via Pearson correlation coefficients.Results: Lunges with blood-flow restriction significantly improved jump height (~ 4.5% ± 0.8%), flight time (~ 3.4% ± 0.3%) and power (~ 4.1% ± 0.3%) within 6-15 min post-exercise (p < 0.05) with the magnitude of effect between blood-flow conditions, moderate-large (0.54-1.16). No significant changes (p > 0.05) were found in jump performance measures following lunge exercises without blood-flow restriction. Significant correlations (p < 0.05) between mechanical contributors of jump performance and jump performance highlighted the potential of blood-flow restriction to enhance stretch-shortening cycle mechanics in the current study.Conclusion: Lunge exercises with blood-flow restriction improved subsequent jump performance in anaerobically trained men. The use of blood-flow restriction may be a practical alternative to heavy resistance training equipment during warm-up protocols. [ABSTRACT FROM AUTHOR]