Tarnopolsky M A, MacLennan D P
Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada L8N 3Z5.
Int J Sport Nutr Exerc Metab. 2000 Dec;10(4):452-63. doi: 10.1123/ijsnem.10.4.452.
Creatine monohydrate supplementation has been shown to enhance high-intensity exercise performance in some but not all studies. Part of the controversy surrounding the ergogenic effect(s) of creatine monohydrate supplementation may relate to design issues that result in low statistical power. A further question that remains unresolved in the creatine literature is whether or not males and females respond in a similar manner to supplementation. We studied the effect of creatine supplementation upon high intensity exercise performance in 24 subjects (n = 12 males, n = 12 females). Creatine monohydrate (Cr; 5g, 4x/d 3 4d) and placebo (Pl; glucose polymer 3 4d) were provided using a randomized, double-blind crossover design (7 week washout). Outcome measures included: 2 3 30-s anaerobic cycle test, with plasma lactate pre- and post-test; dorsi-flexor: maximal voluntary contraction (MVC), 2-min fatigue test, and electrically stimulated peak and tetanic torque; isokinetic knee extension torque and 1-min ischemic handgrip strength. Significant main effects of Cr treatment included: increased peak and relative peak anaerobic cycling power ( 3.7%; p <. 05), dorsi-flexion MVC torque ( 6.6%; p <.05), and increased lactate ( 20.8%; p <.05) with no gender specific responses. We concluded that short-term Cr supplementation can increase indices of high-intensity exercise performance for both males and females.
在一些但并非所有研究中,补充一水肌酸已被证明可提高高强度运动表现。围绕补充一水肌酸的促力效果存在的部分争议可能与设计问题有关,这些问题导致统计效力较低。肌酸文献中尚未解决的另一个问题是,男性和女性对补充剂的反应是否相似。我们研究了补充肌酸对24名受试者(n = 12名男性,n = 12名女性)高强度运动表现的影响。使用随机双盲交叉设计(7周洗脱期)提供一水肌酸(Cr;5克,每日4次,共3 - 4天)和安慰剂(Pl;葡萄糖聚合物,共3 - 4天)。结果指标包括:2次30秒无氧循环测试,测试前后的血浆乳酸水平;背屈肌:最大自主收缩(MVC)、2分钟疲劳测试以及电刺激峰值和强直扭矩;等速膝关节伸展扭矩和1分钟缺血握力。Cr治疗的显著主要效果包括:无氧循环峰值功率和相对峰值功率增加(3.7%;p <.05)、背屈MVC扭矩增加(6.6%;p <.05)以及乳酸增加(20.8%;p <.05),且无性别特异性反应。我们得出结论,短期补充Cr可提高男性和女性高强度运动表现的指标。