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.

Arazi H, Asadi A. The effect of aquatic and land plyometric training on strength, sprint, and balance in young basketball players. J. Hum. Sport Exerc. Vol. 6, No. 1, pp. 101-111, 2011. The purpose of this study was to compare the effect of eight weeks of aquatic and land plyometric training on leg muscle strength, 36.5 and 60 meters sprint times, and dynamic balance test in young male basketball players. Eighteen young male basketball players (age=18.81±1.46 years, height=179.34±6.11 cm, body mass=67.80±9.52 kg, sport experience=4.8±2.47 years) volunteered in this study and divided to three groups; aquatic plyometric training (APT), land plyometric training (LPT) and control group (CON). Experimental groups trained; ankle jumps, speed marching, squat jumps, and skipping drills for eight weeks and 3 times a week for 40 min. The data were analyzed by one way analysis of variance with repeated measures, a Tukey post hoc testing and independent-sample t-test. The results showed there were not any significant differences between the APT and LPT groups in any of the variables tested (P>0.05). Significant increases were observed in posttraining both APT and LPT groups in 36.5-m and 60-m sprint times record compare to pretraining (P<0.05). There was a significant difference in relative improvement between the APT and CON in 36.5-m, 60-m, and one repetition maximum leg press (P<0.05). We conclude that plyometric training in water can be an effective technique to improve sprint and strength in young athletes.

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.

The present study set to examine the effects of different doses of caffeine on performance, rating of perceived exertion (RPE), and pain perception in female teenager athletes of karate. Ten female karate athletes (16.8±1.23 years; height 1.59±0.28 m; body-mass 57.73±8.33 kg; BMI 22.71±3.05 kg/m 2 ) participated in the study. A double-blind, randomized, and crossover counterbalanced design was used. In three sessions (with an interval of seven days'), ten female karate athletes ingested low dose (2 mg/ kg), moderate dose (5 mg/kg) caffeine, and placebo. Sixty minutes after consumption, they performed the tests as below: one repetition maximum and 60% of one repetition maximum in the leg press, explosive power test, and anaerobic RAST test. After the tests, the participants' RPE (6-20 scale) and pain perception (0-10 scale) were recorded using various categorical scales. The results showed that caffeine ingestion at moderate dose significantly reduced RPE and pain perception values compared with the placebo during muscular endurance test (P=0.0001 and P=0.039, respectively). The findings suggest that caffeine dose of 5 mg/kg body mass appears to improve RPE and pain perception in female teenager athletes of karate. The dose of 2 mg/kg body mass does not confer any additional improvement in performance.Uniterms: Caffeine/effects. Karate athletes/performance. Caffeine/rating of perceived exertion. Caffeine/ performance. Caffeine/pain perception. INTRODUCTIONCaffeine (1,3,7-trimethylxanthine) is a plant alkaloid that occurs naturally in the diet (Sökmen et al., 2008) and nearly 90% of US adults consume caffeine in forms of coffee, tea, or other caffeinated food products (8 cup of coffee may contain 50-200 mg caffeine) (Owens, 2015;Yang, Palmer, De Wit, 2010). In the U.S.A., adults ingest an average of 3 mg/kg of caffeine daily in coffee, tea, caffeinated sodas, and many other drinks and food (Sökmen et al., 2008). The popularity of caffeine as an ergogenic aide has increased dramatically over the last decade (Hendrix et al., 2010), Caffeine is the most widely consumed to improve cognitive, physical performance during exercise and has become a popular ergogenic aid among recreational and competitive athletes (Hendrix et al., 2010;Sökmen et al., 2008;Zheng et al., 2014).Caffeine is classified as part of the methylxanthine family of drugs (Cechella et al., 2014;Mohr, Nielsen, Bangsbo, 2011) and is extensively consumed by athletes as an ergogenic aid (Backhouse et al., 2011;Mohr, Nielsen, Bangsbo, 2011) since its removal from the World AntiDoping Agency (WADA) prohibited list of substances (Backhouse et al., 2011;Mohr, Nielsen, Bangsbo, 2011). According to the Medical Council of International Olympic Committee (IOC), caffeine is allowed in sports as long as its urinary excretion level is below 12 µg/mL (Bell, Jacobs, Ellerington, 2001).Taken orally, caffeine reaches a peak plasma concentration of 30-90 min after ingestion, and a halflife has been reported to be 3 to 5 hours with a modest intake of coffee (Sökmen et al.,...

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.