Comparison of traditional and accommodating resistance training with chains on muscular adaptations in young men.

BACKGROUND: Providing accommodating resistance with the use of chains (CRT) is a programming technique that may enhance muscle size, strength, and power. However, there is a paucity of studies comparing the responses to CRT and traditional resistance training (TRT) approaches. This study aimed to examine the effects of 8 weeks of CRT and TRT on muscular adaptations in young recreationally-trained men. METHODS: Thirty men (26±4 y) volunteered to participate in the present study and were randomly assigned to either CRT (N.=10), TRT (N.=10), or a non-exercise control group (CG, N.=10). A resistance-training program (3-4 sets, ~8-12 repetitions at 65-80% of 1RM) was performed three times a week for 8 weeks. Percentage body fat, arm and thigh circumferences, 1RM and endurance (number of repetitions to failure 60% of 1RM) strength tests in the back squat and bench press exercises, and vertical jump power were assessed before and after the intervention. RESULTS: Following the intervention, both training groups demonstrated improvements in strength compared to CG, where greater gains were observed for CRT (e.g., bench press 1RM: CRT=28%; TRT=19% / back squat endurance: CRT=8%; TRT=2%). CONCLUSIONS: The use of chains during resistance training may promote greater gains in strength in young men.

Effects of Progressed and Nonprogressed Volume-Based Overload Plyometric Training on Components of Physical Fitness and Body Composition Variables in Youth Male Basketball Players.

ABSTRACT: Palma-Muñoz, I, Ramírez-Campillo, R, Azocar-Gallardo, J, Álvarez, C, Asadi, A, Moran, J, and Chaabene, H. Effects of progressed and nonprogressed volume-based overload plyometric training on components of physical fitness and body composition variables in youth male basketball players. J Strength Cond Res 35(6): 1642-1649, 2021-This study examined the effect of 6 weeks of progressed and nonprogressed volume-based overload plyometric training (PT) on components of physical fitness and body composition measures in young male basketball players, compared with an active control group. Subjects were randomly assigned to a progressed PT (PPT, n = 7; age = 14.6 ± 1.1 years), a non-PPT (NPPT, n = 8, age = 13.8 ± 2.0 years), or a control group (CG, n = 7, age = 14.0 ± 2.0 years). Before and after training, body composition measures (muscle mass and fat mass), countermovement jump with arms (CMJA) and countermovement jump without arms (CMJ), horizontal bilateral (HCMJ) and unilateral jump with right leg (RJ) and left leg (LJ), 20-cm drop jump (DJ20), sprint speed (10 m sprint), and change of direction speed (CODS [i.e., T-test]) were tested. Significant effects of time were observed for muscle and fat mass, all jump measures, and CODS (all p < 0.01; d = 0.37-0.83). Significant training group × time interactions were observed for all jump measures (all p < 0.05; d = 0.24-0.41). Post hoc analyses revealed significant pre-post performance improvements for the PPT (RJ and LJ: ∆18.6%, d = 0.8 and ∆22.7%, d = 0.9, respectively; HCMJ: ∆16.4%, d = 0.8; CMJ: ∆22.4%, d = 0.7; CMJA: ∆23.3%, d = 0.7; and DJ20: ∆39.7%, d = 1.1) and for the NPPT group (LJ: ∆14.1%, d = 0.4; DJ20: ∆32.9%, d = 0.8) with greater changes after PPT compared with NPPT for all jump measures (all p < 0.05; d = 0.21-0.81). The training efficiency was greater (p < 0.05; d = 0.22) after PPT (0.015% per jump) compared with NPPT (0.0053% per-jump). The PPT induced larger performance improvements on measures of physical fitness as compared to NPPT. Therefore, in-season progressive volume-based overload PT in young male basketball players is recommended.

Effects of different resistance training frequencies on body composition and muscular performance adaptations in men.

BACKGROUND: The aim of this study was to compare the effects of 8 weeks resistance training (RT) with two sessions versus four sessions per week under volume load-equated conditions on body composition, maximal strength, and explosive actions performance in recreationally trained men. METHODS: Thirty-five healthy young men participated in the study and were randomly divided into a two sessions per-week RT (RT2, n = 12), four sessions per-week RT (RT4, n = 13) or a control group (CG, n = 10). All subjects were evaluated for thigh, chest and arm circumference, countermovement jump (CMJ), medicine ball throw (MBT), 1-repetition maximum (1RM) leg press, bench press, arm curl, muscular endurance (i.e., 60% of 1RM to failure) for leg press, and bench press at pre, mid (week 4) and post an 8-week training intervention. RESULTS: A two-way analysis of variance with repeated measures (3 [group] × 3 [time]) revealed that both training groups increased chest and thigh circumferences, strength and explosive actions performance tests in comparison to CG following 8 weeks of training (p = 0.01 to 0.04). Group × time interactions were also noted in 1RM bench press (effects size [ES] = 1.07 vs. 0.89) and arm curl (ES = 1.15 vs. 0.89), with greater gains for RT4 than RT2 (p = 0.03). CONCLUSION: RT improved muscle strength, explosive actions performance and markers of muscle size in recreationally trained men; however, four sessions of resistance training per week produced greater gains in muscular strength for the upper body measures (i.e., 1RM bench press and arm curl) when compared to two sessions per week under volume-equated conditions.

The effect of resistance training set configuration on strength and muscular performance adaptations in male powerlifters.

The purpose of this study was to determine the effects of different set configurations on strength and muscular performance adaptations after an 8-week resistance training program. Twenty-four male powerlifters participated in this study and were randomly assigned to one of two resistance training groups: (1) cluster sets (CS: n = 8), (2), traditional sets (TS: n = 8), and a control group (CG: n = 8). All powerlifters were evaluated for thigh and arm circumference, upper and lower body impulsive activities, and 1 repetition maximum (1RM) in the back squat, bench press, and deadlift prior to and after the 8-week training intervention. After training, both the CS and TS groups increased arm and thigh circumferences and decreased body fat. The CS group resulted in greater increases in upper and lower body impulsive activities than the TS group, respectively. In addition, the CS and TS groups indicated similar changes in 1RM bench press, back squat, and deadlift following the 8 weeks training intervention. These results suggest that cluster sets induce adaptive changes that favor impulsive activities in powerlifters.

Acute effects of strength and endurance exercise on serum BDNF and IGF-1 levels in older men.

BACKGROUND: Regarding an important effects of physical exercise on brain function in elders, the aim of this study was to examine the effects of strength and endurance exercise on brain neurobiological factors in older men. METHODS: Thirty older men volunteered to participate in this study and were randomly assigned to strength, endurance and control groups. The subjects in strength group performed two circuits of resistance exercise (6 exercises with 10 repetition of 65-70% of one repetition maximum), while endurance group performed 30 min running with 65-70% of maximal heart rate. Blood was obtained pre and post-exercise to determine changes in serum BDNF, IGF-1 and platelets. RESULTS: After exercise, both the strength and endurance groups showed significant increases in serum BDNF and IGF-1 concentrations and platelets at post-exercise and in comparison to control group (p < 0.05). In addition, no statistically significant differences were detected between the strength and endurance groups at post-exercise. CONCLUSION: Our findings indicate that both the strength and endurance interventions are effective in elevating BDNF, IGF-1, and platelets, without significant differences between them.

"Comparison of thyroid volume, TSH, free t4 and the prevalence of thyroid nodules in obese and non-obese subjects and correlation of these parameters with insulin resistance status".

BACKGROUND: To compare thyroid volume, thyroid stimulating hormone (TSH), free t4 and the prevalence of thyroid nodules between obese and non-obese subjects. Also, the association between BMI and insulin resistance status with various parameters of thyroid gland was evaluated. METHODS: Fifty-two patients with obesity and 38 volunteers aged 20-50 years with normal body mass index (BMI), were enrolled in this cross-sectional study. Patients with diabetes, history of thyroid disorders, and patients, who were taking medications that influence their blood glucose or insulin levels or modified thyroid function tests, were excluded. TSH, free t4, insulin and glucose and thyroid sonography were carried out and the results compared between two groups. P<0.05 was considered as significant. RESULTS: Thyroid volume was higher (p<0.001) and free t4 was lower (p<0.001) in patients with obesity but there was no difference in TSH between groups. Prevalence of thyroid nodules was 15.7% and 10.8% in obese and non-obese groups, respectively (p=0.51). Frequency of nodules was significantly higher in insulin resistant than non- insulin resistant subjects (22% vs.2%, p=0.01). BMI was associated with thyroid volume (r=0.44, p<0.001) and free t4 (r=-0.35, p=0.001). HOMA-IR (homeostatic model assessment for insulin resistance) had no correlation with thyroid volume (p=0.38), but associated with free t4 (r=-0.25, p=0.01). CONCLUSION: Free T4 was lower and volume of thyroid was higher in obese subjects, but TSH and frequency of thyroid nodules had no significant difference between obese and non-obese counterparts. Insulin resistant individuals had more nodules but thyroid volume was mainly associated with BMI.

Association Between the Acute to Chronic Workload Ratio and Injury Occurrence in Young Male Team Soccer Players: A Preliminary Study.

This study aimed to investigate the relationship between the acute to chronic workload ratio (ACWR), based upon participant session rating of perceived exertion (sRPE), using two models [(1) rolling averages (ACWRRA); and (2) exponentially weighted moving averages (ACWREWMA)] and the injury rate in young male team soccer players aged 17.1 ± 0.7 years during a competitive mesocycle. Twenty-two players were enrolled in this study and performed four training sessions per week with 2 days of recovery and 1 match day per week. During each training session and each weekly match, training time and sRPE were recorded. In addition, training impulse (TRIMP), monotony, and strain were subsequently calculated. The rate of injury was recorded for each soccer player over a period of 4 weeks (i.e., 28 days) using a daily questionnaire. The results showed that over the course of the study, the number of non-contact injuries was significantly higher than that for contact injuries (2.5 vs. 0.5, p = 0.01). There were also significant positive correlations between sRPE and training time (r = 0.411, p = 0.039), ACWRRA (r = 0.47, p = 0.049), and ACWREWMA (r = 0.51, p = 0.038). In addition, small-to-medium correlations were detected between ACWR and non-contact injury occurrence (ACWRRA, r = 0.31, p = 0.05; ACWREWMA, r = 0.53, p = 0.03). Explained variance (r 2) for non-contact injury was significantly greater using the ACWREWMA model (ranging between 21 and 52%) compared with ACWRRA (ranging between 17 and 39%). In conclusion, the results of this study showed that the ACWREWMA model is more sensitive than ACWRRA to identify non-contact injury occurrence in male team soccer players during a short period in the competitive season.

ß-Hydroxy-ß-Methylbutyrate Free Acid Attenuates Oxidative Stress Induced by a Single Bout of Plyometric Exercise.

PURPOSE: The purpose of this study was to examine the effect of ß-hydroxy-ß methylbutyrate free acid (HMB-FA) ingestion on oxidative stress and leukocyte responses to plyometric exercise. METHODS: In a randomized double-blind placebo-controlled design, physically active males were assigned to the HMB-FA (n = 8) or placebo (n = 8) groups that consumed either 1 g of HMB-FA or placebo 30 min prior to performing an acute plyometric exercise protocol (15 sets of 10 repetitions of maximal-effort vertical jumps). Blood was obtained pre-(T1), post-(T2), and 1-h post-(T3) exercise to determine changes in serum levels of 8-hydroxy-2-deoxyguanosine (8-OHdG), malondialdehyde (MDA), protein carbonyl (PC), and white blood cells (WBC). RESULTS: The exercise protocol significantly elevated 8-OHdG (HMB-FA, T2 9.5 and T3 12.6%; placebo, T2 18.2 and T3 36.5%), MDA (HMB-FA, T2 11.6 and T3 25.2%; placebo, T2 11.8 and T3 41%) and PC (HMB-FA, T2 6.9 and T3 25%; placebo, T2 23.4 and T3 55.3%) at post- and 1-h post-exercise, respectively. However, at 1-h post-exercise, greater increases in oxidative stress markers (8-OHdG 36.5 vs. 12.6%; MDA 41 vs. 25.1% and PC 55.3 vs. 25%) were observed in the placebo group compared to the HMB-FA group (p < 0.05). In addition, the WBC level was greater for the placebo group in comparison to the HMB-FA group at post-exercise. CONCLUSION: HMB-FA attenuated oxidative stress and leukocyte responses to plyometric exercise compared with placebo.

Acute Effects of Mental Activity on Response of Serum BDNF and IGF-1 Levels in Elite and Novice Chess Players.

Background and Objectives: Although the effects of physical exercise on brain functions are well studied, the influence of mental activity is unknown. The aim of this study was to assess the influence of a session of mental activity on brain neurobiological factors in chess players. Materials and Methods: Ten elite and novice chess players were recruited to participate in this study as volunteers. The subjects performed a session of standard chess matches as a mental activity. Before and after each chess match, blood samples were drawn to analyze changes in serum brain-derived neurotrophic factor (BDNF) and insulin-like growth factor 1 (IGF-1). Results: After each chess match, both the elite and novice groups showed significant increases in serum BDNF and IGF-1 concentrations. The elite group also showed significantly greater changes in BDNF and IGF-1 levels (p ≤ 0.05) than the novice group. Conclusions: Our findings indicate that a session of standard chess matches as a mental activity is effective for elevating BDNF and IGF-1 levels, and that their elevation in elite players seems to be more pronounced than those in novice players.

The Effects of Beta-Hydroxy-Beta-Methylbutyrate-Free Acid Supplementation and Resistance Training on Oxidative Stress Markers: A Randomized, Double-Blind, Placebo-Controlled Study.

The aim of this study was to investigate the effects of 6-week beta-hydroxy-beta methylbutyrate-free acid (HMB-FA) supplementation on oxidative stress and biochemical variables in responses to resistance training. Sixteen healthy young males participated in this study and were randomly assigned to a HMB-FA supplementation group (n = 8) or a placebo supplementation group (n = 8). The resistance training program was applied for 6 weeks with two sessions per week. Blood samples were collected before and after training, and 8-hydroxy-2-deoxyguanosine (8-OHdG), malondialdehyde (MDA), protein carbonyl (PC), and biochemical variables, such as alanine transaminase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and the numbers of total white blood cells (WBC), neutrophils, lymphocytes, and monocytes were analyzed. Following intervention, both the HMB-FA and placebo supplementation groups showed significant decreases in MDA (effect size [ES]; −0.39, −0.33) and PC (ES; −1.37, −1.41), respectively. However, 8-OHdG did not change after 6 weeks of training in any of the groups. In addition, both groups showed similar training effects on biochemical variables after 6 weeks of intervention. It was concluded that HMB-FA supplementation during resistance training did not add further adaptive changes related to oxidative stress markers.

The effects of maturation on jumping ability and sprint adaptations to plyometric training in youth soccer players.

The aim of this study was to investigate the effects of maturation on power and sprint performance adaptations following 6 weeks of plyometric training in youth soccer players during pre-season. Sixty male soccer players were categorized into 3 maturity groups (Pre, Mid and Post peak height velocity [PHV]) and then randomly assigned to plyometric group and control group. Vertical jump, standing long jump, and 20-m sprint (with and without ball) tests were collected before- and after-intervention. After the intervention, the Pre, Mid and Post-PHV groups showed significant (P ≤ 0.05) and small to moderate effect size (ES) improvement in vertical jump (ES = 0.48; 0.57; 0.73), peak power output (E = 0.60; 0.64; 0.76), standing long jump (ES = 0.62; 0.65; 0.7), 20-m sprint (ES = -0.58; -0.66), and 20-m sprint with ball (ES = -0.44; -0.8; -0.55) performances. The Post-PHV soccer players indicated greater gains than Pre-PHV in vertical jump and sprint performance after training (P ≤ 0.05). Short-term plyometric training had positive effects on sprinting and jumping-power which are important determinants of match-winning actions in soccer. These results indicate that a sixty foot contact, twice per week program, seems effective in improving power and sprint performance in youth soccer players.

Methodological Characteristics and Future Directions for Plyometric Jump Training Research: A Scoping Review.

Recently, there has been a proliferation of published articles on the effect of plyometric jump training, including several review articles and meta-analyses. However, these types of research articles are generally of narrow scope. Furthermore, methodological limitations among studies (e.g., a lack of active/passive control groups) prevent the generalization of results, and these factors need to be addressed by researchers. On that basis, the aims of this scoping review were to (1) characterize the main elements of plyometric jump training studies (e.g., training protocols) and (2) provide future directions for research. From 648 potentially relevant articles, 242 were eligible for inclusion in this review. The main issues identified related to an insufficient number of studies conducted in females, youths, and individual sports (~ 24.0, ~ 37.0, and ~ 12.0% of overall studies, respectively); insufficient reporting of effect size values and training prescription (~ 34.0 and ~ 55.0% of overall studies, respectively); and studies missing an active/passive control group and randomization (~ 40.0 and ~ 20.0% of overall studies, respectively). Furthermore, plyometric jump training was often combined with other training methods and added to participants' daily training routines (~ 47.0 and ~ 39.0% of overall studies, respectively), thus distorting conclusions on its independent effects. Additionally, most studies lasted no longer than 7 weeks. In future, researchers are advised to conduct plyometric training studies of high methodological quality (e.g., randomized controlled trials). More research is needed in females, youth, and individual sports. Finally, the identification of specific dose-response relationships following plyometric training is needed to specifically tailor intervention programs, particularly in the long term.

The effect of resistance training set configuration on strength, power, and hormonal adaptation in female volleyball players.

The primary purpose of this investigation was to determine the impact of altering the set structure during an 8-week resistance training program on anthropometric, hormonal, and strength power characteristics. Thirty female volleyball players were recruited for participation and then randomly assigned to 1 of 3 resistance training groups: (i) cluster sets (CRT; n = 10), (ii) traditional sets (TRT; n = 10), or (iii) control (CON; n = 10). All athletes were evaluated for thigh and arm circumference, vertical jump, 20-m sprint, 4 × 9-m shuttle-run, 1-repetition maximum (1RM) back squat, bench press, military press, and deadlift prior to and after an 8-week periodized training intervention. Blood samples were taken before and after the 8-week training period to evaluate resting testosterone, cortisol, and insulin-like growth factor 1 responses to the training period. After 8 weeks of training the CRT group displayed a small but significant improvement in vertical jump (CRT: effect size (ES) = 038, 7.1%) performance when compared with the TRT group (ES = 0.34, 5.6%). Both the CRT and TRT training interventions resulted in very large increases in the 1RM squat (CRT: 8.4% ± 1.2%; TRT: 7.3% ± 0.6%), bench press (CRT: 8.3% ± 2.0%; TRT: 8.7% ± 1.9%), military press (CRT: 5.7% ± 1.2%; TRT: 5.5% ± 1.6%), and deadlift (CRT: 8.2% ± 1.6%; TRT: 8.3% ± 2.2%). There were no significant differences in 20-m sprint or 4 × 9-m shuttle run times between the CRT, TRT, and CON groups. These results suggest that cluster sets allow for greater improvements in vertical jump performance and equal improvements in strength gains to those seen with traditional sets.

Effects of ß-Hydroxy-ß-methylbutyrate-free Acid Supplementation on Strength, Power and Hormonal Adaptations Following Resistance Training.

BACKGROUND: ß-Hydroxy-ß-methylbutyrate-free acid (HMB-FA) has been ingested prior to exercise to reduce muscle damage, however the effects of HMB-FA supplementation on hormonal, strength and power adaptation are unclear. METHODS: Sixteen healthy men were matched and randomized into two groups and performed six-week resistance training while supplementing with either HMB-FA or placebo (3 g per day). The subjects were evaluated for 1 repetition maximum (1RM) bench press and leg press and vertical jump (VJ) prior to and after training intervention. In addition, blood samples were obtained before and after resistance training to evaluate resting growth hormone (GH), insulin like growth factor 1 (IGF-1), testosterone (TEST), cortisol (CORT), and adrenocorticotropic hormone (ACTH) responses. The HMB-FA supplementation group showed greater gains compared with the placebo group in peak power (effect size ES = 0.26 vs. 0.01) and 1RM leg press (ES = 1.52 vs. 0.96). In addition, the HMB-FA supplementation group indicated greater decrements in ACTH and CORT responses to training in comparison to the placebo group (p < 0.05). Likewise, in GH (ES = 1.41 vs. 0.12) and IGF-1 (ES = 0.83 vs. 0.41), the HMB-FA indicated greater training effects when compared with the placebo group. CONCLUSIONS: These findings provide further support for the potential anabolic benefits associated with HMB-FA supplementation.

Use of anabolic androgenic steroids produces greater oxidative stress responses to resistance exercise in strength-trained men.

The aim of this study was to determine the effect of anabolic androgenic steroids (AAS) use on oxidative stress responses to a single session of resistance exercise in strength-trained men. Twenty-three strength trained men, with 11 self-reporting regular AAS use and 12 self-reporting never taking AAS (NAAS) volunteered to participate in this study. Blood draws were obtained pre and post resistance exercise in order to evaluate changes in oxidative stress biomarkers levels (i.e., 8-hydroxy-2-deoxyguanosine [8-OHdG], malondialdehyde [MDA], and nitric oxide [NO]), antioxidant defense systems (i.e., glutathione peroxidase [GPx] and catalase [CAT]), and glucose (GLU) levels. The AAS users had higher level of 8-OHdG (77.3 ± 17 vs. 57.7 ± 18.2 ng/mg), MDA (85.6 ± 17.8 vs. 52.3 ± 15.1 ng/mL), and GPx (9.1 ± 2.3 vs. 7.1 ± 1.3 mu/mL) compared to NAAS at pre exercise (p < 0.05). Both the experimental groups showed increases in 8-OHdG (p = 0.001), MDA (p = 0.001), GPx (p = 0.001), NO (p = 0.04), CAT (p = 0.02) and GLU (p = 0.001) concentrations after resistance exercise, and the AAS group indicated significant differences in 8-OHdG (p = 0.02) and MDA (p = 0.05) concentrations compared with NAAS users at post exercise. In conclusion, use of AAS is associated with alterations in immune function resulting in oxidative stress, and cell damage; however, high-intensity resistance exercise could increase greater oxidative stress biomarkers in strength-trained men.

Influence of Maturation Stage on Agility Performance Gains After Plyometric Training: A Systematic Review and Meta-analysis.

Asadi, A, Arazi, H, Ramirez-Campillo, R, Moran, J, and Izquierdo, M. Influence of maturation stage on agility performance gains after plyometric training: a systematic review and meta-analysis. J Strength Cond Res 31(9): 2609-2617, 2017-Although plyometric training (PT) improves change of direction (COD) ability, the influence of age on COD gains after PT is unclear. Therefore, the aim of this systematic review was to identify the age-related pattern of improvement in COD ability after PT in youths. A computerized search within 6 databases was performed, selecting studies based on specific inclusion criteria: experimental trials published in English-language journals, PT focused on the lower-body, COD ability measurements reported before and after training, and male participants aged 10 to 18 years. Sixteen articles with a total of 30 effect sizes (ESs) in the experimental groups and 13 ESs in the control groups were included. For the analyses, subjects were categorized into 3 age groups: 10-12.9 years of age (PRE), 13-15.9 years of age (MID), and 16-18 years of age (POST). Independent of age, PT improved COD ability in youths (ES = 0.86, time gains [TG = -0.61]). However, a tendency toward greater COD ability gains was observed in older subjects (MID, ES = 0.95; POST, ES = 0.99) compared with younger subjects (PRE, ES = 0.68). Pearson product-moment correlation (r) indicated that 2-weekly sessions of PT-induced meaningful COD ability gains (for ES, r = 0.436; for TG, r = -0.624). A positive relationship was found between training intensity and ES (r = 0.493). In conclusion, PT improves COD ability in youths, with meaningfully greater effects in older youths. Two PT sessions per week, with 1,400 moderate-intensity jumps for 7 weeks, seems to be an adequate dose.

Effects of Heart Rate vs. Speed-Based High Intensity Interval Training on Aerobic and Anaerobic Capacity of Female Soccer Players.

The purpose of this study was to compare the effects of two types of high-intensity interval training (HIIT) programs on aerobic and anaerobic capacity of female soccer players. Regional-level female athletes were randomly divided into heart rate-based HIIT (n = 8; age 23.4 ± 1.1 year) and speed-based HIIT groups (n = 8; age 23.4 ± 1.3 year). Athletes trained three days per week for six weeks. Before and after training, each athlete's performance was assessed directly through the Hoff test, 30-15 Intermittent Fitness Test (VIFT), and repeated-sprint ability test (RAST); maximal oxygen consumption (VO2max), power and fatigue were estimated indirectly. Both experimental groups improved power, fatigue index and VO2max after training (p < 0.05). It was noteworthy that the speed-based group had greater gains in minimal power (effect size (ES): 3.99 vs. 0.75), average power (ES: 2.23 vs. 0.33), and fatigue index (ES: 2.53 vs. 0.17) compared to heart rate-based group (p < 0.05). In conclusion, both heart rate-based and speed-based HIIT induced meaningful improvements in power, VO2max, and fatigue index in female soccer players, although the speed-based HIIT group achieved greater gains in power and fatigue index compared to the heart rate-based group.

Effects of volume-based overload plyometric training on maximal-intensity exercise adaptations in young basketball players.

BACKGROUND: The aim of the present study was to compare maximal-intensity exercise adaptations in young basketball players (who were strong individuals at baseline) participating in regular basketball training versus regular plus a volume-based plyometric training program in the pre-season period. METHODS: Young basketball players were recruited and assigned either to a plyometric with regular basketball training group (experimental group [EG]; N.=8), or a basketball training only group (control group [CG]; N.=8). The athletes in EG performed periodized (i.e., from 117 to 183 jumps per session) plyometric training for eight weeks. Before and after the intervention, players were assessed in vertical and broad jump, change of direction, maximal strength and a 60-meter sprint test. RESULTS: No significant improvements were found in the CG, while the EG improved vertical jump (effect size [ES] 2.8), broad jump (ES=2.4), agility T test (ES=2.2), Illinois agility test (ES=1.4), maximal strength (ES=1.8), and 60-m sprint (ES=1.6) (P<0.05) after intervention, and the improvements were greater compared to the CG (P<0.05). CONCLUSIONS: Plyometric training in addition to regular basketball practice can lead to meaningful improvements in maximal-intensity exercise adaptations among young basketball players during the pre-season.

The Effects of Plyometric Training on Change-of-Direction Ability: A Meta-Analysis.

PURPOSE: To show a clear picture about the possible variables of enhancements of change-of-direction (COD) ability using longitudinal plyometric-training (PT) studies and determine specific factors that influence the training effects. METHODS: A computerized search was performed, and 24 articles with a total of 46 effect sizes (ESs) in an experimental group and 25 ESs in a control group were reviewed to analyze the role of various factors on the impact of PT on COD performance. RESULTS: The results showed that participants with good fitness levels obtained greater improvements in COD performance (P < .05), and basketball players gained more benefits of PT than other athletes. Also, men obtained COD results similar to those of women after PT. In relation to the variables of PT design, it appears that 7 wk (with 2 sessions/wk) using moderate intensity and 100 jumps per training session with a 72-h rest interval tends to improve COD ability. Performing PT with a combination of different types of plyometric exercises such as drop jumps + vertical jumps + standing long jumps is better than 1 form of exercise. CONCLUSION: It is apparent that PT can be effective at improving COD ability. The loading parameters are essential for exercise professionals, coaches, and strength and conditioning professionals with regard to the most appropriate dose-response trends to optimize plyometric-induced COD-ability gains.

Relationship Between Jumping Ability, Agility and Sprint Performance of Elite Young Basketball Players: A Field-Test Approach / Relação entre capacidade de salto, agilidade e velocidade em jovens jogadores de Basquetebol: uma abordagem com testes de campo

Abstract The purpose of this study was to determine the relationships between sprint, agility and jump performance of elite young basketball players. Sixteen elite national level young male basketball players participated in this study. The jumping ability of each player was determined using countermovement jump (CMJ), and broad long jump (BLJ). The agility T test (TT) and Illinois agility test (IAT) were assessed to determine the agility, and 20-m sprint time was also measured to determine sprint performance. The results of Pearson Product Moment Correlation analysis indicated moderate correlation between training age and IAT (r = -0.57; p = 0.021). Strong correlations were found between CMJ and BLJ (r = 0.71; p = 0.002), and between TT and IAT (r = 0.70; p = 0.002). Similarly, 20-m sprint time was strong correlated with CMJ (r = -0.61; p = 0.011), BLJ (r = -0.76; p = 0.001), TT (r = 0.77; p = 0.001), and IAT (r = 0.68; p = 0.003). In addition, CMJ was strongly correlated with TT (r = -0.60; p = 0.013), and IAT (r = -0.64; p = 0.007), and also strong correlation between BLJ with TT (r = -0.85; p = 0.001) and IAT (r = -0.76; p = 0.001). The findings of the present study indicated significant correlation between sprint and agility, jumping ability and sprint performance and between jumping ability and agility performance in basketball players. Therefore, the results suggest that sprint, agility and jumping ability share common physiological and biomechanical determinants.

Resumo Objetivou-se determinar a relação entre velocidade, agilidade e capacidade de salto em jovens jogadores de Basquetebol. Dezesseis jovens atletas de basquetebol de Elite (Iran) foram avaliados. A capacidade de salto foi avaliada por meio do teste contramovimento ( Jump Test - CJT) e o salto em comprimento (Long Jump – LJ). A agilidade foi avaliada por meio do Teste T (TT) e do Teste de Illinois (TI). A velocidade foi avaliada por meio do teste de 20 metros. Os resultados do Coeficiente de Correlação de Pearson (r) indicaram moderada correlação entre a idade e o TI (r = -0,57; p = 0,021). Correlações de magnitude forte foram encontradas entre CJT e LJ (r = 0,71; p = 0,002), o TT e TI (r = 0,70; p = 0,002). As correlações com o teste de velocidade de 20 metros foram de magnitude elevada com o CJT (r = -0,61; p = 0,011), LJ (r = -0,76; p = 0,001), TT (r = 0,77; p = 0,001), e o TI (r = 0,68; p = 0,003). Além disso, CJT foi fortemente correlacionado com TT (r = -0,60; p = 0,013), e TI (r = -0,64; p = 0,007), e também entre o LJ com TT (r = -0,85; p = 0,001) e TI (r = -0,76; p = 0,001). Os achados desse estudo indicaram correlação entre velocidade e agilidade, capacidade de salto e velocidade e entre capacidade de salto e agilidade em jovens atletas de basquetebol. Os resultados sugerem que velocidade, agilidade e capacidade de salto apresentam determinantes fisiológicos e biomecânicos em comum.