科研之友
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摘要
The aim of this study was to investigate the effects of a 4-week weight reduction period with high protein and reduced carbohydrate intake on body composition, explosive power, speed, serum hormones, and acid-base balance in male track and field jumpers and sprinters. Eight participants were assigned to a high weight reduction group (HWR; energy restriction 750 kcal.d(-1)) and 7 to a low weight reduction group (LWR; energy restriction 300 kcal.d(-1)). Energy and carbohydrate intake decreased significantly (p <= 0.05) only in HWR by 740 +/- 330 kcal.d(-1) and 130 +/- 29 g.d(-1), respectively. Furthermore, total body mass and fat mass decreased (p <= 0.05) only in HWR by 2.2 +/- 1.0 kg and 1.7 +/- 1.6 kg, respectively. Fat-free mass (FFM), serum testosterone, cortisol, and sex hormone-binding globulin did not change significantly. Ca2+ ion and pH decreased (p <= 0.05) only in HWR (3.1 +/- 2.8% and 0.8 +/- 0.8%, respectively), whereas HCO3- declined (p <= 0.05) in both groups by 19.3 +/- 6.2% in HWR and by 13.1 +/- 8.5% in LWR. The countermovement jump and 20-m sprint time improved consistently (p <= 0.05) only in HWR, by 2.6 +/- 2.5 cm and 0.04 +/- 0.04 seconds, respectively. Finally, athletes with a fat percentage of 10% or more at the baseline were able to preserve FFM. In conclusion, altered acid-base balance but improved weight-bearing power performance was observed without negative consequences on serum hormones and FFM after a 4-week weight reduction of 0.5 kg.wk(-1) achieved by reduced carbohydrate but maintained high protein intake.
- 出版日期2015-1
