The aim of this study was to test the hypothesis that β-alanine supplementation improves punch power and frequency in amateur boxers during a simulated contest. Sixteen amateur boxers (each approximately 6 yr experience) were assigned to β-alanine (n = 8; 1.5 g 4 times/d for 4 wk) or placebo supplementation (n = 8) after initially being assessed for baseline punch performance. Before and after the supplementation period, all boxers completed a simulated contest consisting of 3 × 3-min rounds (interspersed with 60-s rests) on a punching bag (with a force transducer attached). Each round involved performing 2 min 50 s standardized punching (standardized jab, cross combination) based on notation analysis, whereas the last 10 s involved maximal-output punching (standardized jab, cross combination), during which time punch force and frequency were recorded. Postcontest blood lactate was significantly increased in the β-alanine group (presupplementation 9.5 ± 0.9 mmol/L, postsupplementation 12.6 ± 0.5 mmol/L, p < .05), whereas the placebo group showed no change (presupplementation 8 ± 2.8 mmol/L, postsupplementation 7.0 ± 2.7 mmol/L; p > .05). During the 10-s maximal-output punching, changes in mean punch force (β-alanine 20 ± 1.01 kg, placebo 1 ± 1 kg) and punch frequency (β-alanine 5 ± 4, placebo –2 ± 3) were greater (p < .05) in the β-alanine-supplemented group. The authors conclude that β-alanine supplementation improves punching performance in amateur boxers and suggest that this supplementation protocol may also prove ergogenic for other combat-related sports.
Tim Donovan, Tim Ballam, James P. Morton and Graeme L. Close
Marcus Smith, Rosemary Dyson, Tudor Hale, Matthew Hamilton, John Kelly and Peggy Wellington
This study examined the effects of serial reductions in energy and fluid intake on two simulated boxing performances separated by 2 days recovery. Eight amateur boxers (age: 23.6 ± 3.2 years; height 175 ± 5 cm; body mass [BM] 73.3 ± 8.3 kg [Mean ± SD]) performed two simulated boxing bouts (BB) under normal (N-trial) and restricted (R-trial) diets in a counterbalanced design over 5 days. The trials were separated by a 9-day period of normal dietary behavior (X-trial). BM was recorded on days 1, 3, and 5 of each trial. Simulated bouts of three, 3-min rounds with 1-min recovery were completed on days 3 (BB1) and 5 (BB2) of each 5-day trial. Punching force (N) was recorded from 8 sets of 7 punches by a purpose-built boxing ergometer. Heart rate (fC) was monitored continuously (PE3000 Polar Sports Tester, Kempele, Finland), and blood lactate (BLa) and glucose (BG) were determined 4-min post-performance (2300 StaPlus, YSI, Ohio). Energy and fluid intakes were significantly lower in the R-trial (p < .05). Body mass was maintained during the N-trial but fell 3% (p < .05) during the R-trial. There were no significant differences in end-of-bout fC or post-bout BG, but BLa was higher in the N- than the R-trial (p < .05). R-trial punching forces were 3.2% and 4.6% lower, respectively, compared to the corresponding N-trial bouts, but the differences did not reach statistical significance. These results suggest that energy and fluid restrictions in weight-governed sports do not always lead to a significant decrease in performance, but because of the small sample size and big variations in individual performances, these findings should be interpreted with care.
Sociodemographic, Health-Related, and Psychological Factors in Users and Nonusers of Nutritional Supplements in Fitness Club Participants in Tehran, Iran Pouya Saeedi * Mohd Nasir Mohd Taib * Hazizi Abu Saad * 10 2012 22 22 5 5 323 323 330 330 10.1123/ijsnem.22.5.323 β-Alanine Improves Punch Force and