title: The effects of restricted energy and fluid intake on simulated amateur boxing performance.
abstract: 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.
authors: Centre for Sports Science and Medicine at the University College Chichester, College Lane, Chichester PO19 4 PE, UK.
authors: M
authors: M
authors: Smith
authors: R
authors: R
authors: Dyson
authors: T
authors: T
authors: Hale
authors: M
authors: M
authors: Hamilton
authors: J
authors: J
authors: Kelly
authors: P
authors: P
authors: Wellington
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D001914:Boxing / Q000502:physiology*; D003681:Dehydration / Q000503:physiopathology*; D004038:Diet, Reducing; D002149:Energy Intake / Q000502:physiology*; D005080:Exercise Test; D006339:Heart Rate; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D014868:Water Deprivation / Q000502:physiology*; D015431:Weight Loss
chemical_list: D001786:Blood Glucose; D019344:Lactic Acid