Walker L S, Bemben M G, Bemben D A, Knehans A W
Department of Health & Sport Sciences, University of Oklahoma, Norman, USA.
Med Sci Sports Exerc. 1998 Dec;30(12):1730-7. doi: 10.1097/00005768-199812000-00012.
The purpose of this study was to assess the effects of 14 wk of chromium picolinate supplementation during the final 16 wk of a preseason resistance and conditioning program on body composition and neuromuscular performance in NCAA Division I wrestlers. During this phase of training, wrestlers are primarily interested in trying to improve physical performance and wrestling technique and are not engaged in severe, acute weight loss practices commonly employed before competition.
This double-blinded, randomized placebo-controlled study involved 20 wrestlers from the University of Oklahoma assigned to either a treatment group (Cr+3; N = 7; 20.4 yr +/- 0.1) receiving 200 micrograms chromium picolinate daily, a placebo group (P; N = 7; 19.9 yr +/- 0.2), or a control group (C; N = 6; 20.2 yr +/- 0.1) using a stratified random sampling technique based on weight classification. Body composition, neuromuscular performance, metabolic performance, and serum insulin and glucose were measured before and immediately following the supplementation and training period.
Repeated measures ANOVA indicated no significant changes in body composition for any of the groups. Aerobic power increased significantly (P < 0.002) in all groups, independent of supplementation. There were significant trial and group x trial interactions for upper body endurance (P = 0.038) and relative bench press power (P = 0.050). Post-hoc analyses revealed that the C group increased upper body endurance (P = 0.006), but none of the pre- to post-test changes in bench press power were significant.
These results suggest that chromium picolinate supplementation coupled with a typical preseason training program does not enhance body composition or performance variables beyond improvements seen with training alone.
本研究旨在评估在大学体育协会(NCAA)一级摔跤运动员季前赛抗性和体能训练计划的最后16周中,补充14周吡啶甲酸铬对身体成分和神经肌肉性能的影响。在训练的这个阶段,摔跤运动员主要关注的是提高身体性能和摔跤技术,并且不进行比赛前常用的剧烈、快速减重训练。
这项双盲、随机、安慰剂对照研究涉及来自俄克拉荷马大学的20名摔跤运动员,采用基于体重分类的分层随机抽样技术,将他们分为治疗组(Cr+3;N = 7;20.4岁±0.1),每天接受200微克吡啶甲酸铬;安慰剂组(P;N = 7;19.9岁±0.2);或对照组(C;N = 6;20.2岁±0.1)。在补充和训练期前后测量身体成分、神经肌肉性能、代谢性能以及血清胰岛素和葡萄糖。
重复测量方差分析表明,所有组的身体成分均无显著变化。所有组的有氧能力均显著提高(P < 0.002),与补充剂无关。在上身耐力(P = 0.038)和相对卧推力量(P = 0.050)方面,存在显著的试验以及组×试验交互作用。事后分析显示,C组的上身耐力有所提高(P = 0.006),但卧推力量的测试前至测试后变化均不显著。
这些结果表明,补充吡啶甲酸铬并结合典型的季前训练计划,并不会比单独训练带来的改善更能增强身体成分或性能变量。