Countermovement Jump Peak Power Research Articles

Relationship Between Individual and Composite FMS™ Scores with the Anthropometric and Physical Characteristics of Elite Touch (Rugby) Players

Abstract Purpose To describe and compare the movement patterns, anthropometric and physical characteristics of male and female Touch players; and examine the relationships between Functional Movement Screening (FMS™) scores and the anthropometric and physical characteristics. Methods This was a cross-sectional study with 35 elite Touch players (18 males, age = 24.7 ± 4.9 years; 17 females, age = 26.7 ± 5.2 years). Anthropometric (stature, body mass) and physical characteristics (sprint times, glycolytic change-of-direction test, and countermovement jump (CMJ) flight time and peak power) were assessed alongside movement patterns using the FMS™ battery. Data were analysed for between-sex differences (independent t-test, Mann–Whitney U) and relationships (Spearman’s correlation coefficient). Results Between-sex differences in body mass (t = 6.082, P < 0.001), stature (t = 9.247, P < 0.001), CMJ flight time (t = 3.576, P = 0.001), relative CMJ peak power (t = 6.578, P < 0.001), 10 m sprint time (t = 15.861, P < 0.001), glycolytic change of direction test time (t = − 11.831, P < 0.001) and Yo–Yo IR1 (t = 6.842, P < 0.001) were observed. There were minimal differences for deep squat (Z = − 1.036, P = 0.443), in-line lunge (Z = − 1.284, P = 0.303), shoulder mobility (Z = − 0.173, P = 0.883), trunk stability push-up (Z = − 0.896, P = 0.483) and rotary stability (Z = − 1.537, P = 0.273). The correlation between total and individual FMS™ scores with anthropometric and physical characteristics ranged from trivial-to-moderate (r = − 0.502 to 0.488). Conclusion The lack of difference for the FMS™ composite score and small-to-trivial differences in individual scores allows a comparison between mixed populations within Touch. Whilst many of the correlations were trivial-to-small, there were differences between sexes in the associations and evidence that improvements in functional deficiencies could translate into improved physical performance.

Recovery and stress monitoring in elite ice hockey: A longitudinal pilot-study

Introduction
 Young athletes in high-level sports experience a greater risk for injury and illness during phases of increased training and competitive load. When recovery is too sparse under these circumstances, psychological and physical health problems could emerge. These are referred to as nonfunctional overreaching or overtraining syndrome, OTS (Daly et al., 2022; Jones et al., 2017; Kiely, 2018). OTS is typically characterized by a reduction in athletic performance that lasts for several weeks to months, accompanied with mood and sleep disturbances, feelings of depression, respiratory tract infections, weight loss, and other symptoms. The prevalence of this condition is high with approxymately 10-20 % of young adult and about 29 % of young athletes from various sports beeing affected (Matos et al., 2011). To our knowledge, no scientifically valid and reliable measurement system currently exists, which would allow the preventive, early diagnosis of overreaching states that might lead to OTS (Weakley et al., 2022). The aim of this study is to develop and evaluate a multiparameter measurement system to assess the recovery and stress state of high-level athletes.
 Methods
 Twenty-five male ice hockey players from the highest level Swiss leagues at their respective age group participated (i.e., National League, NL, n = 11, age = 24.8 ± 4.1 years and U20, n = 14, age = 18.5 ± 1.5 years). Over 5-10 weeks during the in-season (i.e., competition phase) measurements were performed on 10 separate days, either after 1 day of passive recovery (T1) or after a day with match/intensive training (T2). The measurement battery included counter movement jump (CMJ), heart rate variability (HRV), executive functions (EF), tympanic temperature (Temp), and Stress Recovery Short Scale (SRSS).
 Results
 Independent Student’s t-tests showed significant differences (p < 0.05) between timepoints T1 and T2 for CMJ (peak power per body mass), HRV (sympathic and parasympatic indexes), and SRSS (recovery, stress, total score); but not for CMJ (jump height), EF and Temp.
 Discussion/Conclusion
 We conclude that various measurment parameters, including CMJ performance, HRV indices, and subjective ratings of recovery and stress could provide valuable feedback for athletes, coaches, and medical staff regarding a potential overreaching or OTS state.
 References
 Daly, E., Pearce, A. J., Esser, P., & Ryan, L. (2022). Evaluating the relationship between neurological function, neuromuscular fatigue, and subjective performance measures in professional rugby union players. Frontiers in Sports and Active Living, 4, Article 1058326. https://doi.org/10.3389/fspor.2022.1058326
 Jones, C. M., Griffiths, P. C., & Mellalieu, S. D. (2017). Training load and fatigue marker associations with injury and illness: A systematic review of longitudinal studies. Sports Medicine, 47(5), 943-974. https://doi.org/10.1007/s40279-016-0619-5
 Kiely, J. (2018). Periodization theory: Confronting an inconvenient truth. Sports Medicine, 48(4), 753-764. https://doi.org/10.1007/s40279-017-0823-y
 Matos, N. F., Winsley, R. J., & Williams, C. A. (2011). Prevalence of nonfunctional overreaching/overtraining in young English athletes. Medicine & Science in Sports & Exercise, 43(7), 1287-1294. https://doi.org/10.1249/MSS.0b013e318207f87b
 Weakley, J., Halson, S. L., & Mujika, I. (2022). Overtraining syndrome symptoms and diagnosis in athletes: Where is the research? A systematic review. International Journal of Sports Physiology and Performance, 17(5), 675-681. https://doi.org/10.1123/ijspp.2021-0448

Changes in eccentric utilization ratio, reactive strength index and leg stiffness in highly trained sprinters between training phases

Changes in eccentric utilization ratio, reactive strength index and leg stiffness in highly trained sprinters between training phases

Between-Session Reliability of Strength- and Power-Related Variables Obtained during Isometric Leg Press and Countermovement Jump in Elite Female Ice Hockey Players

Isometric leg press (ILP) and countermovement jump (CMJ) are commonly used to obtain strength- and power-related variables with important implications for health maintenance and sports performance. To enable the identification of true changes in performance with these measurements, the reliability must be known. This study evaluates the between-session reliability of strength- and power-related measures obtained from ILP and CMJ. Thirteen female elite ice hockey players (21.5 ± 5.1 years; 66.3 ± 8.0 kg) performed three maximal ILPs and CMJs on two different occasions. Variables from the ILP (peak force and peak rate of force development) and CMJ (peak power, peak force, peak velocity, and peak jump height) were obtained. The results were reported using the best trial, an average of the two best trials, or an average of three trials. The intraclass correlation coefficient (ICC) and coefficient of variation (CV) were high (ICC > 0.97; CV < 5.2%) for all outcomes. The CV for the CMJ (1.5–3.2%) was lower than that for the ILP (3.4–5.2%). There were no differences between reporting the best trial, an average of the two best trials, or an average of the three trials for the outcomes. ILP and CMJ are highly reliable when examining strength- and power-related variables in elite female ice hockey players.

Training Load, Neuromuscular Fatigue, and Well-Being of Elite Male Volleyball Athletes During an In-Season Mesocycle.

Most high-intensity bouts of exercise in volleyball consist of jumping activities, which are responsible for inducing muscle damage, high levels of fatigue, and muscle soreness. Therefore, the aim of the current study was to quantify and analyze the training loads, neuromuscular fatigue, and perceptual well-being of a 5-week in-season mesocycle carried out by a professional male volleyball team. Fifteen volleyball players (age 28.51 [5.39]y; height 193.19 [9.87]cm; body mass 88.46 [13.18]kg) participated in this study. Internal training load assessed through the rating of perceived exertion, external training load (ETL; evaluated using an inertial motion unit), countermovement jump (CMJ) height and peak power, and wellness questionnaire responses were obtained from all athletes. Results indicated a progressive decrease of the internal training load during the week and by the undulatory pattern of the ETL during the microcycles. Moreover, training monotony increased across the microcycles and was negatively associated with CMJ peak power (r = -.681, P < .05). Finally, sleep quality (ρ = -.747, P < .01) and fatigue (ρ = -.789, P < .01) were negatively associated with weekly ETL. This study indicated that sleep quality and fatigue were negatively associated with weekly ETL. Therefore, decreases in weekly ETL might be needed to improve sleep quality and decrease fatigue in professional volleyball players. Plus, higher values of training monotony were associated with lower values of CMJ peak power. Consequently, avoiding training monotony might be important to improve jumping performance in professional volleyball athletes.

Effects of Eurycoma longifolia Jack supplementation on eccentric leg press exercise-induced muscle damage in rugby players.

Eurycoma longifolia Jack (ELJ) is a herbal plant that has androgenic and antioxidant effects. We investigated the short-term effect of ELJ supplementation on muscle damage induced by eccentric exercise. Eighteen young (19-25 years), well-trained rugby 7s players were assigned to an ELJ or a placebo (PLA) group (n = 9/group). Each participant took four 100-mg capsules a day for seven days prior to performing a leg press eccentric exercise to failure in a double-blind fashion. Peak force, peak power and jump height in countermovement jump (CMJ), drop jump reactive strength index (RSI), muscle soreness assessed by a 100-mm visual analogue scale, plasma creatine kinase (CK) activity, and salivary hormones were measured at 24 h before and 0.5, 24, 48, 72, and 96 h after the exercise. Changes in the variables over time were compared between the groups by two-factor mixed-design ANOVA. The number of eccentric contractions performed was similar (P = 0.984) between the ELJ (21 ± 5) and PLA groups (21 ± 5). Salivary testosterone and cortisol concentrations did not change (P > 0.05) after the supplementation for both groups. CMJ peak power (-9.4 ± 5.6%) and height (-10.6 ± 4.9%), and RSI (-15.2 ± 16.2%) decreased at 24 h after exercise (P < 0.05), and muscle soreness (peak: 89 ±10 mm) and plasma CK activity (peak: 739 ± 420 IU/L) increased after exercise (P < 0.05) without significant differences between groups. These results showed that 7-day ELJ supplementation prior to the leg press eccentric exercise had no significant effects on hormones, performance and muscle damage markers for the athletes.

The Relationship of Lower-Body, Multijoint, Isometric and Dynamic Neuromuscular Assessment Variables With Snatch, and Clean and Jerk Performance in Competitive Weightlifters: A Meta-Analysis

ABSTRACT The purpose of this meta-analysis was to synthesize the literature and provide a robust estimate of the correlations between lower-body, multijoint, isometric and dynamic neuromuscular assessment variables and snatch (SN) and clean and jerk (C&amp;J) performance in competitive weightlifters. A comprehensive search through 3 electronic databases (PubMed, SPORTDiscus, and Web of Science) returned 12 studies that met the inclusion criteria. Meta-analyses were performed on Pearson's correlations between SN and C&amp;J performance and 15 variables from 5 neuromuscular assessments—countermovement jump (CMJ), squat jump (SJ), isometric midthigh pull (IMTP), back squat (BS), and front squat (FS) one repetition maximum (1RM). The FS and BS 1RM exhibited nearly perfect correlations (r = 0.93 to 0.94), whereas the IMTP peak force exhibited very large correlations (r = 0.83 to 0.85). The IMTP force at 250 ms exhibited very large correlations (r = 0.77 to 0.78), and the CMJ and SJ peak power exhibited very large to nearly perfect correlations (r = 0.88 to 0.92). These findings illustrate the importance of lower-body maximal and time-limited force-producing capabilities in weightlifters. Moreover, each assessment offers at least one variable that exhibits a correlation of &gt;0.70. Therefore, these assessments may be used to gauge weightlifting performance potential.

The Effect Of Cluster-sets Resistance Priming Training On Delayed Potentiation Of Athletes

Cluster sets (CS) resistance training can induce greater post-activation potentiation (PAP) effects than traditional sets (TS) by reducing fatigue. The neuromuscular performance response demonstrated in delayed potentiation (DLP) effects is similar to that in PAP, they are all based on the relationship between potentiation and fatigue. However, it is not clear whether CS resistance training can induce greater DLP effects. OBJECTIVE The aim of the study was to compare the delayed potentiation (DLP) effects induced by cluster sets (CS) versus traditional sets (TS) resistance priming (RP) training. METHODS Sixteen male collegiate athletes were recruited for the study in a crossover design. All the subjects performed a CS (30s interval between reps, 4 minutes interval between sets) and a TS (no rest between reps, 4 minutes interval between sets) RP training sessions (3 sets of 3 repetitions of barbell back squat at 85%1RM) in random order separated by 72 hours. countermovement jump (CMJ),20-meters sprint, and T-test were evaluated at baseline and 6 hours after the RP training sessions. RESULTS 6 hours after the RP sessions, both the CS and TS significantly improved the CMJ height (CS: 50.44 ± 8.35 cm, ES = 0.48; TS: 48.35 ± 8.05 cm, ES = 0.23), CMJ take-off velocity (CS: 3.21 ± 0.28 m/s, ES = 0.56; TS: 3.16 ± 0.27 m/s, ES = 0.38), CMJ push-off impulse (CS: 237.3 ± 26.99Ns, ES = 0.38; TS: 233.8 ± 24.96Ns, ES = 0.26), 20-meters sprint (CS: 2.967 ± 0.139 s, ES = 0.85; TS: 3.007 ± 0.122 s, ES = 0.58) and T-test (CS:9.805 ± 0.535 s, ES = 0.99; TS: 9.921 ± 0.64 s, ES = 0.73) performance compared with baseline values. The CMJ peak power (64.42 ± 8.92 W/kg, ES = 0.3) were significant better following the CS compared with baseline values. The CMJ height (ES = 0.25), CMJ peak power (ES = 0.2), 20-meters sprint (ES = 0.31) were significant better following the CS compared with the TS training session. No inter-condition significant difference was observed in CMJ take-off velocity (ES = 0.18), CMJ push-off impulse (ES = 0.13), and T-test (ES = 0.2). CONCLUSIONS Compared with TS, CS RP training resulted in greater DLP effects after 6 hours, and significantly improving athletes’ lower limb speed performance and power output.

Comparison of Countermovement Jump and Squat Jump Performance Between 627 State and Non-State Representative Junior Australian Football Players.

Edwards, T, Weakley, J, Woods, CT, Breed, R, Benson, AC, Suchomel, TJ, and Banyard, HG. Comparison of countermovement jump and squat jump performance between 627 state and non-state representative junior Australian football players. J Strength Cond Res 37(3): 641-645, 2023-This cross-sectional study investigated differences in lower-body power of state and nonstate representative junior Australian football (AF) players through countermovement jump (CMJ) and squat jump (SJ) performance. A total of 627 players performed the CMJ and SJ at the end of the preseason phase over a 2-week period, with each player grouped according to their age (under 18 [U18] or under 16 [U16]), and highest competition level played (state representation and nonstate representation). One-way multivariate analysis of variance (MANOVA), follow up ANOVA's, and Cohen's d effect sizes were used to identify significant main effects and between-group differences. Statistical significance was set at α < 0.05. Significant small-to-moderate effect size differences were observed between competition level, with state U18 and U16 players recording greater CMJ and SJ height, and peak power (PP), compared with their nonstate representative peers, respectively. Similarly, significant small-to-moderate effect size differences existed between age groups, with nonstate U18 players recording greater CMJ and SJ height and PP than nonstate U16 counterparts. However, state U18 and state U16 only differed in CMJ PP. No differences were found between competition level or age groups for the difference between CMJ and SJ jump height (CMJSJ diff ). Together, these findings suggest that state and nonstate representative junior AFs may have a similar ability to use the stretch-shortening cycle, despite state representative players jumping higher in the CMJ and SJ.

Effects of Simultaneously Combined Whole-Body Electrostimulation and Plyometric Training on Vertical Jump Performance, 20 m Sprint-Time and Handgrip Strength

Abstract Introduction. The aim of the present study was to investigate the effects of a 6-week low intensity plyometric training (PT) + whole-body electrostimulation (WBES) combined program, compared with traditional PT, on vertical jump performance, 20 m sprint-time and handgrip strength. Material and methods. 10 male and 10 female Physical Education students were randomly allocated to a control (CON) or an experimental (EXP) group. Both groups performed a 6-week low intensity PT 3 days per week, and during the third day, PT was simultaneously combined with WBES in the EXP group. Countermovement jump (CMJ) height, CMJ peak power, 20 m sprint-time and handgrip strength were measured before (pre-test) and after (post-test) the training period. Repeated measures ANOVA was performed to identify differences after the training program. Effect sizes (ES) were assessed using Hedge’s g. Results. No significant differences between groups were observed at post-test. CMJ height and CMJ peak power significantly increased in both groups, with greater ES in the EXP group (p &lt; 0.001, g = 0.68; p &lt; 0.001, g = 0.70, respectively). 20 m sprint-time significantly improved in both groups, with greater ES in the CON group (p &lt; 0.001, g = −1.68). Handgrip strength also increased in both groups, but ES were minimal. Conclusions. Both training methods demonstrated to be a good strategy to improve CMJ performance and 20 m sprint-time. The most effective training method for improving CMJ performance was PT + WBES combined program, and traditional PT obtained better results in 20 m sprint-time.

The mobility limitation in healthy older people is due to weakness and not slower muscle contractile properties.

The maximal power generating capacity of a muscle declines with age and has a negative impact on the performance of daily life activities. As muscle power is the product of force and velocity, we recruited 20 young (10 men, 10 women: 20–31 years) and 20 older (10 men, 10 women: 65–86 years) people to investigate which of these components contributes to the lower power and performance in old age. After determination of the maximal isometric knee extension torque (MVC), they performed a countermovement jump (CMJ) in 1) the normal situation (normal), 2) with an extra load of 15% body weight (loaded) and 3) 15% lower body weight (unloaded with a pulley system), and a timed up-and-go test (TUG) in the normal or loaded condition. The TUG and CMJ performance was lower in old than young participants (p<0.001). Below a critical CMJ peak power of ~23.7 W·kg-1 TUG showed a progressive decrease. The CMJ take-off velocity (Voff) in the normal condition was lower in old than young participants (p<0.001). However, the Voff vs. body weight/MVC relationship of the normal, loaded and unloaded data combined was similar in the old and young participants and fitted the Hill equation (R2 = 0.396). This indicates that 1) only when peak power drops below a critical threshold TUG becomes impaired and 2) there was no evidence for intrinsic slowing of the muscle contractile properties in older people, but rather the older people were working on a slower part of the force-velocity relationship due to weaker muscles.

Not All Physical Performance Tests Are Related to Early Season Match Running Performance in Professional Rugby League.

Glassbrook, DJ, Fuller, JT, Wade, JA, and Doyle, TLA. Not all physical performance tests are related to early season match running performance in professional rugby league. J Strength Cond Res 36(7): 1944-1950, 2022-This study aimed to determine which physical tests correlate with early season running performance. Sixteen professional rugby league players performed the 30-15 intermittent fitness test (IFT), 1.2-km time trial, 1 repetition maximum (RM) barbell back squat, isometric midthigh pull (IMTP), countermovement jump (CMJ), barbell squat jump (SJ), and ballistic bench press throw (BBP). Bivariate Pearson's correlations and linear regression were used to compare physical tests with peak match running intensities recorded by a portable Global Positioning System and represented by peak match velocity and acceleration, as well as peak 1-, 4-, 6-, and 8-minute instantaneous acceleration/deceleration periods of play. Significant (p < 0.05) negative correlations (r = -0.55 to -0.60) were observed between the IFT and relative 1-, 4-, 6-, and 8-minute peaks, and between the relative 1RM back squat and relative 1-, 4-, 6-, and 8-minute peaks. Significant positive correlations (r = 0.52-0.84) were observed between the following physical tests and match performance pairs: IFT and peak acceleration; relative 1RM back squat and peak acceleration; SJ peak power (relative and absolute) and peak acceleration; CMJ peak force (relative and absolute) and peak acceleration; CMJ peak power (relative and absolute) and peak acceleration and 1-, 4-, 6-, and 8-minute peaks; and relative BBP peak power and peak velocity and peak acceleration. The results of this study highlight that not all generic tests of physical qualities are related to peak match running performance and only those with significant correlations are likely to be able to indicate how players may perform during match-play.

Effects of age and sex on field-based measures of muscle strength and power of the upper and lower body in adolescents

ABSTRACT Field-based tests including the medicine ball chest throw (MBCT) and vertical jump are used to assess muscle performance. To date no study has compared performances of these field-based tests in adolescents across a range of ages. The aim of this study was to examine the effects of age and sex on MBCT and countermovement jump (CMJ) performance in adolescents.This cross-sectional study involved 2192 adolescents (1477 males and 715 females) aged between 12 and 17 years. Trials of the MBCT and CMJ were performed with CMJ peak power estimated. Males had significantly greater MBCT distance, CMJ height and CMJ peak power at each consecutive age group separated by 1 year (p < 0.001). Females generally showed significantly greater performances across a larger age range of at least 2 years for MBCT (p ≤ 0.004) and CMJ peak power (p ≤ 0.018). Males had greater performances than females for MBCT distance, CMJ height, and CMJ peak power from 13 years and above (p < 0.001). Sex differences widened with increasing age for all tests from ~5-8% at 12 years progressing to 24–29% at 16–17 years. This study shows the effects of age and sex is similar for both the MBCT and CMJ tests in adolescents.

An Intramuscular Injection of Mixed Testosterone Esters Does Not Acutely Enhance Strength and Power in Recreationally Active Young Men

Purpose: Limited data are available on the acute performance-enhancing effects of single-dose administration of testosterone in healthy humans. Studies of testosterone administrations to healthy humans are rare due to the difficult nature and necessity of close clinical monitoring. However, our unique physiological experimental facilities combined with close endocrinological collaboration have allowed us to safely complete such a study. We tested the hypothesis that an intramuscular injection of 250 mg mixed testosterone esters (TEs) enhances physical performance in strength and power exercises acutely, measured 24 h after injection. Additionally, we investigated whether the basal serum testosterone concentration influences the performance in countermovement jump (CMJ), 30-s all out cycle sprint, and one-arm isometric elbow flexion.Methods: In a randomized, double-blind, placebo-controlled design, 19 eugonadal men received either a TE (n = 9, 23 ± 1 years, 183 ± 7 cm, 83 ± 10 kg) or a PLA (n = 10, 25 ± 2 years, 186 ± 6 cm, 82 ± 14 kg) injection. Hormonal levels and the performance in CMJ, 30-s all out cycle sprint, and one-arm isometric elbow flexion were measured before and 24 h after injection.Results: Firstly, an intramuscular injection of 250 mg mixed TEs did not enhance the vertical jump height in a CMJ test, peak power, mean power, and fatigue index in a 30-s all-out cycle sprint or rate of force development and maximal voluntary contraction in a one-arm isometric elbow flexion 24 h post-injection. Secondly, baseline testosterone levels appeared not to influence performance in strength and power exercises to a large extent in healthy, recreationally active young men.Conclusion: A single intramuscular injection of 250 mg mixed TEs has no acute ergogenic effects on strength and power performance in recreationally active, young men. This novel information has implication for basic physiological understanding. Whether the same applies to an elite athlete population remains to be determined. If so, this would have implications for anti-doping efforts aiming to determine the most cost-efficient testing programs.

Back squat velocity to assess neuromuscular status of rugby league players following a match

ObjectivesBack squat mean concentric velocity (MV) and countermovement jump (CMJ) performance were examined in sub-elite rugby league players post-match to monitor changes in neuromuscular status (NMS) from baseline. Relationships between changes in back squat MV and CMJ performance variables were used to compare back squat MV to an established method to monitor NMS. DesignLongitudinal observational design. Methods18 male sub-elite rugby league players (mean±SD, 20.5±2.4 yr; 180.0±6.7cm; 93.3±11.2kg) performed 3 repetitions of CMJ and back squat with an individualised, pre-determined load at −2h (baseline), +30min, +24h, and +48h in relation to a match. Back squat MV, CMJ height, CMJ peak power, and CMJ peak velocity were measured with a linear position transducer. ResultsSignificant (p<0.05), small to large decreases (ES=0.52–1.24) were observed in back squat MV up to +48h post-match. Significant (p<0.05), small to moderate decreases (ES=0.52–0.70) in CMJ height were also observed up to +24h post-match, returning to baseline at +48h. CMJ peak power and peak velocity post-match changes were not significant compared to baseline (p>0.05). Significant positive correlations were found between changes in back squat MV and CMJ height at +30min (r=0.59; p=0.009) and +48h (r=0.51; p=0.03). ConclusionsThese findings suggest back squat MV may be a suitable alternative or addition to CMJ testing for monitoring NMS in rugby league players.

Neuromuscular predictors of competition performance in advanced international female weightlifters: a cross-sectional and longitudinal analysis

ABSTRACTThe aim of this study was to investigate the physical determinants of weightlifting competition performance based on Isometric Mid-Thigh Pull (IMTP) and Countermovement Jump (CMJ) force-time variables, in a cross-sectional and longitudinal analysis. Ten British advanced international female weightlifters’ competition results and neuromuscular assessment data collected as part of the British Weight Lifting World Class Programme were utilised for the purpose of this study. All data were averaged for two consecutive 1-year periods. The cross-sectional analysis utilised the second year of data, whereas the longitudinal analysis assessed the mean change between the two years. The cross-sectional analysis results reveal IMTP Net Isometric Peak Force (PF) and CMJ Peak Power (PP) predict 94.2%, 95.1% and 91.8% of the variance in Total, Snatch and Clean & Jerk competition performance, respectively (p = <0.5). The longitudinal analysis results revealed that ∆IMTP PF was the only predicting factor of longitudinal change in weightlifting competition performance predicting 41.5%, 41.7% and 42.5% of ∆Total, ∆Snatch and ∆Clean & Jerk, respectively (p = <0.5). The assessments and equations may be utilised by coaches or sports scientists to inform the prescription of training and help predict competition performance.

Effect of Postactivation Potentiation After Medium vs. High Inertia Eccentric Overload Exercise on Standing Long Jump, Countermovement Jump, and Change of Direction Performance.

Beato, M, De Keijzer, KL, Leskauskas, Z, Allen, WJ, Dello Iacono, A, and McErlain-Naylor, SA. Effect of postactivation potentiation after medium vs. high inertia eccentric overload exercise on standing long jump, countermovement jump, and change of direction performance. J Strength Cond Res 35(9): 2616-2621, 2021-This study aimed to evaluate the postactivation potentiation (PAP) effects of an eccentric overload (EOL) exercise on vertical and horizontal jumps and change of direction (COD) performance. Twelve healthy physically active male subjects were involved in a crossover study. The subjects performed 3 sets of 6 repetitions of EOL half squats for maximal power using a flywheel ergometer. Postactivation potentiation using an EOL exercise was compared between a medium (M-EOL) vs. high inertia (H-EOL) experimental condition. Long jump (LJ) was recorded at 30 seconds, 3, and 6 minutes after both EOL exercises and compared with baseline values (control). The same procedure was used to assess countermovement jump (CMJ) height and peak power and 5-m COD test (COD-5m). A fully Bayesian statistical approach to provide probabilistic statements was used in this study. Long jump performance reported improvements after M-EOL and H-EOL exercise (Bayes factor [BF10] = 32.7, strong; BF10 = 9.2, moderate), respectively. Countermovement jump height (BF10 = 135.6, extreme; BF10 > 200, extreme), CMJ peak power (BF10 > 200, extreme; BF10 = 56.1, very strong), and COD-5m (BF10 = 55.7, very strong; BF10 = 16.4, strong) reported improvements after M-EOL and H-EOL exercise, respectively. Between analysis did not report meaningful differences in performance between M-EOL and H-EOL exercises. The present outcomes highlight that PAP using an EOL (M-EOL and H-EOL) improves LJ, CMJ height, CMJ peak power, and COD-5m in male athletes. The optimal time window for the PAP effect was found for both EOL conditions from 3 to 6 minutes. However, M-EOL and H-EOL produce similar PAP effect on LJ, CMJ, and COD-5m tasks.

Modification of Strength Training Programs in Handball Players and its Influence on Power During the Competitive Period.

A high level of muscle power is necessary for the effective use of technique during handball competitions. The presented research concentrated on comparing the effectiveness of two training modes directed towards the development of muscle power – plyometric and traditional strength training. Furthermore, we evaluated whether resistance training performed twice a week was sufficient to guarantee an increase in muscle power of handball players. We also investigated whether strength training designed according to the “waving” model (one training session per week oriented towards the development of maximal strength and one towards the development of power) was sufficient to increase muscle power in handball players. The study included 28 professional handball players who were divided into 3 groups: Group 1 subjected to additional strength training (8 individuals), Group 2 subjected to traditional plyometric training (8 individuals) and Group 3 following standard training (12 individuals). Research was conducted at the beginning and at the end of the 1st round of competitions and consisted of the following measurements: CMJ (countermovement jump) and SJ (squat jump), a 10-s trial on a cycle-ergometer and ball-throwing velocity. Analysis of the results showed that both the plyometric and strength training programs induced a statistically significant increase in jumping height and generated power during the CMJ. The group subjected to additional strength training achieved greater increases in CMJ power than the group carrying out plyometric training, which in case of the CMJ peak power turned out to be statistically significant (p < 0.05). Different results were obtained when studying changes in the flight speed of the thrown ball; the group undergoing plyometric training registered minor increases (significant in the standing throw ), and there were decreases in the flight speed of the thrown ball (significant in the leaning back throw) in the group following the traditional strength training program.

Effects of 8-Week Thera-Band Training on Spike Speed, Jump Height and Speed of Upper Limb Performance of Young Female Volleyball Players

ABSTRACT: Introduction and objectives: Elastic resistance has been commonly used in the therapeutic and fitness setting. However, the effects of a strength training program using elastic resistance exercises to the explosive power and spike speed, which are very important elements for successful volleyball practice, has not been clearly demonstrated. Therefore, the aim of this study was to establish the effects of 8-week Thera-Band training protocols on the development of spike speed, counter movement jump (CMJ) height, peak power and speed of upper limb performance of young female volleyball players. Methods: The participants consists of 20 competitive female volleyball players who regularly train at the same team and aged 15-17 years (age 16.2 ± 0.7 years). All the players were tested for spike speed, CMJ height, peak power and speed of upper limb performances before and after 8-week training program. The players were divided into Thera-Band Training Group (TTG; n=10) and Control Group (CG; n=10). Both groups continued technical and tactical volleyball training together 3 days (120 min.d.-1) a week. Additionally, TTG attended Thera-Band training program through 8-week, 2 days per week and 2 sessions (60 min.d.-1). Results: The findings of the study showed significant change in CMJ height, peak power and spike speed at the end of 8-week. TTG significantly (p ≤ .001) improved CMJ height, peak power and spike speed, whereas the CG showed significant changes only CMJ height and peak power (p ≤ .05) at the end of 8-week. The effect of resistance exercises was significantly higher as compared to the control group (p &lt; .05). Results demonstrated that the TTG players showed greater improvements in CMJ height (d = 1.31, moderate effect size), and spiking speed (d = 2.93, large effect size) performance than CG. Conclusion: It can be concluded that supervised Thera-Band training contributed development of the performance of spike speed mostly and CMJ height and peak power of lower extremities in young female volleyball players. Due to its effectiveness on muscular performance, the Thera-Band training model can be recommended to the coaches and players in additional to the regular technical training.

Soccer Match Play as an Important Component of the Power-Training Stimulus in Premier League Players.

Competitive match play is a dominant component of the physical load completed by soccer players in a training microcycle. Characterizing the temporal disruption in homeostasis that follows exercise may provide some insight on the potential for match play to elicit an adaptive response. Countermovement-jump (CMJ) performance was characterized 3d postmatch for 15 outfield players from an English Premier League soccer team (age 25.8 ± 4.1y, stature 1.78 ± 0.08m, body mass: 71.7 ± 9.1kg) across a season. These players were classified as either starters (n = 9) or nonstarters (n = 6), according to their average individual playing time (more or less than 60min/match). Linear mixed models were used to investigate the influence of indicators of match activity (total distance covered [TD] and high-intensity running distance [HI]) on CMJ height and peak power (PP). Starting players covered much greater TD (ES = 1.5) and HI (ES = 1.4) than nonstarters. Furthermore, there was a possible positive effect of HI on CMJ height and PP. This relationship suggests that an additional 0.6km of HI would increase CMJ height and PP by slightly more than the smallest-worthwhile-change values of 0.6cm and 1.0W/kg, respectively. This small yet practically relevant increase in performance may suggest that match play, more specifically the intense activities that are associated with the match, provides a physiological stimulus for neuromuscular adaptation. These data may have implications for the preparation of soccer squads, especially the training requirements of starting and nonstarting players.