Effects of Different Plyometric Training Frequencies on Components of Physical Fitness in Amateur Female Soccer Players

Plyometric jump training (PJT) is a frequently used and effective means to improve amateur and elite soccer players' physical fitness. However, it is unresolved how different PJT frequencies per week with equal overall training volume may affect training-induced adaptations. Therefore, the aim of this study was to compare the effects of an in-season 8 week PJT with one session vs. two sessions per week and equal training volume on components of physical fitness in amateur female soccer players. A single-blind randomized controlled trial was conducted. Participants (N = 23; age, 21.4 +/- 3.2 years) were randomly assigned to a one session PJT per-week (PJT-1, n = 8), two sessions PJT per-week (PJT-2, n = 8) or an active control group (CON, n = 7). Before and after training, participants performed countermovement jumps (CMJ), drop-jumps from a 20-cm drop-height (DJ20), a maximal kicking velocity test (MKV), the 15-m linear sprint-time test, the Meylan test for the assessment of change of direction ability (CoDA), and the Yo-Yo intermittent recovery endurance test (Yo-YoIR1). Results revealed significant main effects of time for the CMJ, DJ20, MKV, 15-m sprint, CoDA, and the Yo-YoIR1 (all p 0.05; Delta 0.5-4.2%, d = 0.03-0.2). In conclusion, higher PJT exposure in terms of session frequency has no extra effects on female soccer players' physical fitness development when jump volume is equated during a short-term (i.e., 8 weeks) training program. From this, it follows that one PJT session per week combined with regular soccer-specific training appears to be sufficient to induce physical fitness improvements in amateur female soccer players.We acknowledge the support of the Deutsche Forschungsgemeinschaft (DFG), and Open Access Publishing Fund of University of Potsdam, Germany

Short-Term Seasonal Development of Anthropometry, Body Composition, Physical Fitness, and Sport-Specific Performance in Young Olympic Weightlifters

The aim of this study is to monitor short-term seasonal development of young Olympic weightlifters’ anthropometry, body composition, physical fitness, and sport-specific performance. Fifteen male weightlifters aged 13.2 1.3 years participated in this study. Tests for the assessment of anthropometry (e.g., body-height, body-mass), body-composition (e.g., lean-body-mass, relative fat-mass), muscle strength (grip-strength), jump performance (drop-jump (DJ) height, countermovement-jump (CMJ) height, DJ contact time, DJ reactive-strength-index (RSI)), dynamic balance (Y-balance-test), and sport-specific performance (i.e., snatch and clean-and-jerk) were conducted at different time-points (i.e., T1 (baseline), T2 (9 weeks), T3 (20 weeks)). Strength tests (i.e., grip strength, clean-and-jerk and snatch) and training volume were normalized to body mass. Results showed small-to-large increases in body-height, body-mass, lean-body-mass, and lower-limbs lean-mass from T1-to-T2 and T2-to-T3 (D0.7–6.7%; 0.1 d 1.2). For fat-mass, a significant small-sized decrease was found from T1-to-T2 (D13.1%; d = 0.4) and a significant increase from T2-to-T3 (D9.1%; d = 0.3). A significant main effect of time was observed for DJ contact time (d = 1.3) with a trend toward a significant decrease from T1-to-T2 (D–15.3%; d = 0.66; p = 0.06). For RSI, significant small increases from T1-to-T2 (D9.9%, d = 0.5) were noted. Additionally, a significant main effect of time was found for snatch (d = 2.7) and clean-and-jerk (d = 3.1) with significant small-to-moderate increases for both tests from T1-to-T2 and T2-to-T3 (D4.6–11.3%, d = 0.33 to 0.64). The other tests did not change significantly over time (0.1 d 0.8). Results showed significantly higher training volume for sport-specific training during the second period compared with the first period (d = 2.2). Five months of Olympic weightlifting contributed to significant changes in anthropometry, body-composition, and sport-specific performance. However, hardly any significant gains were observed for measures of physical fitness. Coaches are advised to design training programs that target a variety of fitness components to lay an appropriate foundation for later performance as an elite athlete

Effects of Resistance Training on Change-of-Direction Speed in Youth and Young Physically Active and Athletic Adults: A Systematic Review with Meta-Analysis

BACKGROUND:Change-of-direction (CoD) speed is a physical fitness attribute in many field-based team and individual sports. To date, no systematic review with meta-analysis available has examined the effects of resistance training (RT) on CoD speed in youth and adults. OBJECTIVE:To aggregate the effects of RT on CoD speed in youth and young physically active and athletic adults, and to identify the key RT programme variables for training prescription. DATA SOURCES:A systematic literature search was conducted with PubMed, Web of Science, and Google Scholar, with no date restrictions, up to October 2019, to identify studies related to the effects of RT on CoD speed. STUDY ELIGIBILITY CRITERIA:Only controlled studies with baseline and follow-up measures were included if they examined the effects of RT (i.e., muscle actions against external resistances) on CoD speed in healthy youth (8-18 years) and young physically active/athletic male or female adults (19-28 years). STUDY APPRAISAL AND SYNTHESIS METHODS:A random-effects model was used to calculate weighted standardised mean differences (SMD) between intervention and control groups. In addition, an independent single training factor analysis (i.e., RT frequency, intensity, volume) was undertaken. Further, to verify if any RT variable moderated effects on CoD speed, a multivariate random-effects meta-regression was conducted. The methodological quality of the included studies was assessed using the physiotherapy evidence database (PEDro) scale. RESULTS:Fifteen studies, comprising 19 experimental groups, were included. The methodological quality of the studies was acceptable with a median PEDro score of 6. There was a significant large effect size of RT on CoD speed across all studies (SMD = - 0.82 [- 1.14 to - 0.49]). Subgroup analyses showed large effect sizes on CoD speed in males (SMD = - 0.95) contrasting with moderate improvements in females (SMD = - 0.60). There were large effect sizes on CoD speed in children (SMD = - 1.28) and adolescents (SMD = - 1.21) contrasting with moderate effects in adults (SMD = - 0.63). There was a moderate effect in elite athletes (SMD = - 0.69) contrasting with a large effect in subelite athletes (SMD = - 0.86). Differences between subgroups were not statistically significant. Similar improvements were observed regarding the effects of independently computed training variables. In terms of RT frequency, our results indicated that two sessions per week induced large effects on CoD speed (SMD = - 1.07) while programmes with three sessions resulted in moderate effects (SMD = - 0.53). For total training intervention duration, we observed large effects for ≤ 8 weeks (SMD = - 0.81) and > 8 weeks (SMD = - 0.85). For single session duration, we found large effects for ≤ 30 min and ≥ 45 min (both SMD = - 1.00). In terms of number of training sessions, we identified large effects for ≤ 16 sessions (SMD = - 0.83) and > 16 sessions (SMD = - 0.81). For training intensity, we found moderate effects for light-to-moderate (SMD = - 0.76) and vigorous-to-near maximal intensities (SMD = - 0.77). With regards to RT type, we observed large effects for free weights (SMD = - 0.99) and machine-based training (SMD = - 0.80). For combined free weights and machine-based training, moderate effects were identified (SMD = - 0.77). The meta-regression outcomes showed that none of the included training variables significantly predicted the effects of RT on CoD speed (R2 = 0.00). CONCLUSIONS:RT seems to be an effective means to improve CoD speed in youth and young physically active and athletic adults. Our findings indicate that the impact of RT on CoD speed may be more prominent in males than in females and in youth than in adults. Additionally, independently computed single factor analyses for different training variables showed that higher compared with lower RT intensities, frequencies, and volumes appear not to have an advantage on the magnitude of CoD speed improvements. In terms of RT type, similar improvements were observed following machine-based and free weights training

Change of direction speed in youth male soccer players: The predictive value of anthropometrics and biological maturity

This is an accepted manuscript of a paper published by Human Kinetics on 05/05/2022 available online at: ttps://doi.org/10.1123/pes.2021-0178 The accepted manuscript of the publication may differ from the final published version.This study aimed to develop the optimal allometric body size/shape and a biological maturity model that predicted the change of direction (CoD) mean speed performance in youth male soccer players. One-hundred and fifteen youth soccer players (age: 12.4 [1.3] y) participated in this study. The 505 test was used to assess CoD mean speed performance. Anthropometric measurements comprised body height (cm), sitting height (cm), body mass (kg), fat mass (kg), lower limb length (cm), thigh length (cm), leg length (cm), foot length (cm), thigh girth (cm), and calf girth (cm). The maturity status was determined based on the maturity offset method. To identify size/shape and maturity characteristics associated with CoD speed performance, we computed a multiplicative allometric log-linear regression model, which was refined using backward elimination. The multiplicative allometric model exploring the association between 505 CoD mean speed performance and the different anthropometric characteristics in youth soccer players estimated that fat mass (P < .001), sitting height (P = .02), and maturity offset (P = .004) are the key predictors. More specifically, youths who are more mature and have a lower fat mass and a shorter trunk length, are likely to achieve a better CoD mean speed performance. These findings highlight the relevance of considering anthropometric and maturity characteristics in youth soccer players to support talent identification.Published versio

Cold Water Immersion Enhanced Athletes’ Wellness and 10-m Short Sprint Performance 24-h After a Simulated Mixed Martial Arts Combat

Objective: The aim of the present study was to examine the effect of Cold Water Immersion (CWI) on the recovery of physical performance, hematological stress markers and perceived wellness (i.e., Hooper scores) following a simulated Mixed Martial Arts (MMA) competition.Methods: Participants completed two experimental sessions in a counter-balanced order (CWI or passive recovery for control condition: CON), after a simulated MMAs competition (3 × 5-min MMA rounds separated by 1-min of passive rest). During CWI, athletes were required to submerge their bodies, except the trunk, neck and head, in the seated position in a temperature-controlled bath (∼10°C) for 15-min. During CON, athletes were required to be in a seated position for 15-min in same room ambient temperature. Venous blood samples (creatine kinase, cortisol, and testosterone concentrations) were collected at rest (PRE-EX, i.e., before MMAs), immediately following MMAs (POST-EX), immediately following recovery (POST-R) and 24 h post MMAs (POST-24), whilst physical fitness (squat jump, countermovement-jump and 5- and 10-m sprints) and perceptual measures (well-being Hooper index: fatigue, stress, delayed onset muscle soreness (DOMS), and sleep) were collected at PRE-EX, POST-R and POST-24, and at PRE-EX and POST-24, respectively.Results: The main results indicate that POST-R sprint (5- and 10-m) performances were ‘likely to very likely’ (d = 0.64 and 0.65) impaired by prior CWI. However, moderate improvements were in 10-m sprint performance were ‘likely’ evident at POST-24 after CWI compared with CON (d = 0.53). Additionally, the use of CWI ‘almost certainly’ resulted in a large overall improvement in Hooper scores (d = 1.93). Specifically, CWI ‘almost certainly’ resulted in improved sleep quality (d = 1.36), stress (d = 1.56) and perceived fatigue (d = 1.51), and ‘likely’ resulted in a moderate decrease in DOMS (d = 0.60).Conclusion: The use of CWI resulted in an enhanced recovery of 10-m sprint performance, as well as improved perceived wellness 24-h following simulated MMA competition

Acute effects of different balance exercise types on selected measures of physical fitness in youth female volleyball players

Background!#!Earlier studies have shown that balance training (BT) has the potential to induce performance enhancements in selected components of physical fitness (i.e., balance, muscle strength, power, speed). While there is ample evidence on the long-term effects of BT on components of physical fitness in youth, less is known on the short-term or acute effects of single BT sessions on selected measures of physical fitness.!##!Objective!#!To examine the acute effects of different balance exercise types on balance, change-of-direction (CoD) speed, and jump performance in youth female volleyball players.!##!Methods!#!Eleven female players aged 14 years participated in this study. Three types of balance exercises (i.e., anterior, posterolateral, rotational type) were conducted in randomized order. For each exercise, 3 sets including 5 repetitions were performed. Before and after the performance of the balance exercises, participants were tested for their static balance (center of pressure surface area [CoP SA] and velocity [CoP V]) on foam and firm surfaces, CoD speed (T-Half test), and vertical jump height (countermovement jump [CMJ] height). A 3 (condition: anterior, mediolateral, rotational balance exercise type) × 2 (time: pre, post) analysis of variance was computed with repeated measures on time.!##!Results!#!Findings showed no significant condition × time interactions for all outcome measures (p &amp;gt; 0.05). However, there were small main effects of time for CoP SA on firm and foam surfaces (both d = 0.38; all p &amp;lt; 0.05) with no effect for CoP V on both surface conditions (p &amp;gt; 0.05). For CoD speed, findings showed a large main effect of time (d = 0.91; p &amp;lt; 0.001). However, for CMJ height, no main effect of time was observed (p &amp;gt; 0.05).!##!Conclusions!#!Overall, our results indicated small-to-large changes in balance and CoD speed performances but not in CMJ height in youth female volleyball players, regardless of the balance exercise type. Accordingly, it is recommended to regularly integrate balance exercises before the performance of sport-specific training to optimize performance development in youth female volleyball players.!##!Trial registration!#!This study does not report results related to health care interventions using human participants and therefore it was not prospectively registered

Effects of Equal Volume But Different Plyometric Jump Training Intensities on Components of Physical Fitness in Physically Active Young Males

Ramirez-Campillo, R, Moran, J, Drury, B, Williams, M, Keogh, JW, Chaabene, H, and Granacher, U. Effects of equal volume but different plyometric jump training intensities on components of physical fitness in physically active young males. J Strength Cond Res XX(X): 000–000, 2019—An 8-week single-blind randomized controlled trial was conducted to compare the effects of separate programs of equal volume, but different intensity, plyometric jump training (PJT), on physical fitness in healthy adults. Thirty-eight physically active males (mean age: 21.8 6 2.5 years) participated. Subjects were randomly assigned to one of 3 PJT groups or a control (CON, n = 9) according to their jump performance. Plyometric jump training was conducted at maximal (PJT-100, n = 10), high (PJT-80, n = 9), or moderate (PJT-65, n = 10) intensity within each group. Baseline and follow-up tests were performed for the assessment of countermovement jump (CMJ) height, CMJ height with arm swing (CMJA), and drop jump height from a 20-cm drop box (DJ20), linear speed (30 m), and change-of-direction speed (CODS) (the Illinois CODS test). Results revealed significant group 3 time interactions for CMJ, CMJA, DJ20, 30-m sprint, and CODS (all p , 0.001; d = 0.39–0.76). Post hoc analyses showed significant improvements in all 5 fitness measures for PJT-100 (all p , 0.01, D3.7–13.5%, d = 0.26–1.4). For PJT-80, 3 of 5 fitness tests demonstrated significant change (CMJ: p , 0.001, D5.9%, d = 0.33; CMJA: p , 0.001, D7.0%, d = 0.43; CODS: p , 0.001, D3.9%, d = 0.9), and for PJT-65, only 1 test was significant (CMJ: p , 0.05, D2.8%, d = 0.15). No significant changes were observed in CON. Except for similar gains in DJ20 and 30-m sprint in PJT-100 and PJT-80, gains in physical fitness were, in general, greater (p , 0.05) after PJT-100 vs. PJT-80 vs. PJT-65 vs. CON. Therefore, maximal PJT intensity may induce larger physical fitness gains, although high and moderate intensities may also be useful, but to a lesser exten

Technical-tactical analysis of small combat games in male kickboxers: effects of varied number of opponents and area size

Background: To handle the competition demands, sparring drills are used for specific technical-tactical training as well as physical-physiological conditioning in combat sports. While the effects of different area sizes and number of within-round sparring partners on physiological and perceptive responses in combats sports were examined in previous studies, technical and tactical aspects were not investigated. This study investigated the effect of different within-round sparring partners number (i.e., at a time; 1 vs. 1, 1 vs. 2, and 1 vs. 4) and area sizes (2&nbsp;m\u2009 7\u20092&nbsp;m, 4&nbsp;m\u2009 7\u20094&nbsp;m, and 6&nbsp;m\u2009 7\u20096&nbsp;m) variation on the technical-tactical aspects of small combat games in kickboxing. Method: Twenty male kickboxers (mean\u2009\ub1\u2009standard deviation, age: 20.3\u2009\ub1\u20090.9 years), regularly competing in regional and national events randomly performed nine different kickboxing combats, lasting 2&nbsp;min each. All combats were video recorded and analyzed using the software Dartfish. Results: Results showed that the total number of punches was significantly higher in 1 versus 4 compared with 1 versus 1 (p\u2009=\u20090.011, d\u2009=\u20090.83). Further, the total number of kicks was significantly higher in 1 versus 4 compared with 1 versus 1 and 1 versus 2 (p\u2009&lt;\u20090.001; d\u2009=\u20090.99 and d\u2009=\u20090.83, respectively). Moreover, the total number of kick combinations was significantly higher in 1 versus 4 compared with 1 versus 1 and 1 versus 2 (p\u2009&lt;\u20090.001; d\u2009=\u20091.05 and d\u2009=\u20090.95, respectively). The same outcome was significantly lower in 2&nbsp;m\u2009 7\u20092&nbsp;m compared with 4&nbsp;m\u2009 7\u20094&nbsp;m and 6&nbsp;m\u2009 7\u20096&nbsp;m areas (p\u2009=\u20090.010 and d\u2009=\u2009-\u20090.45; p\u2009&lt;\u20090.001 and d\u2009=\u2009-\u20090.6, respectively). The number of block-and-parry was significantly higher in 1 versus 4 compared with 1 versus 1 (p\u2009&lt;\u20090.001, d\u2009=\u20091.45) and 1 versus 2 (p\u2009=\u20090.046, d\u2009=\u20090.61) and in 2&nbsp;m\u2009 7\u20092&nbsp;m compared with 4&nbsp;m\u2009 7\u20094&nbsp;m and 6\u2009 7\u20096&nbsp;m areas (p\u2009&lt;\u20090.001; d\u2009=\u20090.47 and d\u2009=\u20090.66, respectively). Backwards lean actions occurred more often in 2&nbsp;m\u2009 7\u20092&nbsp;m compared with 4&nbsp;m\u2009 7\u20094&nbsp;m (p\u2009=\u20090.009, d\u2009=\u20090.53) and 6&nbsp;m\u2009 7\u20096&nbsp;m (p\u2009=\u20090.003, d\u2009=\u20090.60). However, the number of foot defenses was significantly lower in 2&nbsp;m\u2009 7\u20092&nbsp;m compared with 6&nbsp;m\u2009 7\u20096&nbsp;m (p\u2009&lt;\u20090.001, d\u2009=\u20091.04) and 4&nbsp;m\u2009 7\u20094&nbsp;m (p\u2009=\u20090.004, d\u2009=\u20090.63). Additionally, the number of clinches was significantly higher in 1 versus 1 compared with 1 versus 2 (p\u2009=\u20090.002, d\u2009=\u20090.7) and 1 versus 4 (p\u2009=\u20090.034, d\u2009=\u20090.45). Conclusions: This study provides practical insights into how to manipulate within-round sparring partners' number and/or area size to train specific kickboxing technical-tactical fundamentals. Trial registration: This study does not report results related to health care interventions using human participants and therefore it was not prospectively registered