Physical profile of junior and senior amateur boxers

© JPES. Purpose: The purpose of this study was to profile the physiological characteristics of amateur boxers using a battery of tests designed to assess the physiological and physical demands required for performance. Fifteen junior amateur (age 14.9 ± 2.0 years; stature 164 ± 12 cm; body mass 50.9 ± 11.3 kg) and sixteen senior amateur boxers (n = 16; age 20.5 ± 4.0 years; stature 174 ± 9 cm; body mass 65.2 ± 10.7 kg) provided informed consent to participate in the study. Body composition, squat jump (SJ), countermovement jump (CMJ), 5-and 10 m sprint (5SP/10SP), press up (PU), right and left medicine-ball single-arm throws (MBR, MBL), repeated sprint test (RST) and Yo-Yo intermittent recovery test level 1 (YY) were performed. The likelihood (% chance) of between-group differences were assessed using a magnitude based approach, standardised-difference score (Cohen’s d) and 90% confidence intervals [CI]. Linear regression (r) was used to examine the association between variables. Results: Senior boxers outperformed (79 to 99% chance) junior counterparts in PU, YY, CMJ, SJ, 10SP, MBL and MBR tests (d ≥ 0.50 [-0.34 to 1.61]). There were very large (r 0.70) correlations between fat free mass, upper-and lower body lean mass and medicine ball throw distance. There were large correlations (r 0.50 to 0.69) between medicine ball throw distance and CMJ, SJ, PU, 5SP and 10SP. Conclusions: A simple and time-effective test battery was able to differentiate performance between junior and amateur boxers. These assessments could be useful when profiling junior and senior amateur boxers

Caffeine gum improves 5 km running performance in recreational runners completing parkrun events

Purpose The purpose of this study was to determine whether caffeine gum improves the performance of recreational runners completing parkruns (weekly, 5 km, mass participant running events). Methods Thirty-six recreational runners (M = 31, F = 5; age 33.7 ± 10.7 y; BMI 23.1 ± 2.4 kg/m2) capable of running 5 km in < 25 min were recruited to a study at the Sheffield Hallam parkrun, UK. Runners were block randomized into one of three double-blind, placebo-controlled, cross-over intervention trials with caffeine gum as the treatment (n = 6 per intervention trial) or into one of three non-intervention trials that ran concurrently with the intervention trials (n = 6 per non-intervention trial). Changes in conditions across different parkruns were adjusted for using data from the non-intervention trials. Runners in the randomized cross-over intervention trials chewed gum supplying 300 mg of caffeine or a placebo gum for 5 min, starting 30 min before each parkrun. Results Caffeine gum improved 5 km parkrun performance by a mean of 17.28 s (95% CI 4.19, 30.37; P = 0.01). Adjustment for environmental conditions using data from the non-intervention trials attenuated the statistical significance (P = 0.04). Caffeine gum also decreased RPE by 1.21 (95% CI 0.30, 2.13; P = 0·01) units relative to placebo. Conclusions A 300 mg dose of caffeine supplied in chewing gum improved the performance of recreational runners completing 5 km parkruns by an average of 17 s. Trial Registration The study was registered at ClinicalTrials.gov: NCT02473575 before recruitment commenced

A–Z of nutritional supplements: dietary supplements, sports nutrition foods and ergogenic aids for health and performance—Part 29

Part 29 includes two supplements which are traditionally paired (phlogenzym and wobenzym) and which have been popular in the Eastern Bloc countries though hardly, if at all, used by athletes in the UK and USA. Phosphatidylserine (a phospholipid present in cell membranes) and plant sterols (several of which have been dealt with in the previous issues of this series) are also discussed here