Cribb Paul J, Williams Andrew D, Hayes Alan
Exercise Metabolism Unit, Center for Ageing, Rehabilitation, Exercise and Sport and School of Biomedical Sciences, Victoria University, Victoria, Australia.
Med Sci Sports Exerc. 2007 Nov;39(11):1960-8. doi: 10.1249/mss.0b013e31814fb52a.
Studies attributing gains in strength and lean body mass (LBM) to creatine monohydrate (CrM) during resistance exercise (RE) training have not assessed these changes alongside cellular and subcellular adaptations. Additionally, CrM-treated groups have seldom been compared with a group receiving a placebo similar in nitrogen and energy. The purpose of this study was to examine the effects of a CrM-containing protein-carbohydrate (PRO-CHO) supplement in comparison with a supplement containing a similar amount of nitrogen and energy on body composition, muscle strength, fiber-specific hypertrophy, and contractile protein accrual during RE training.
In a double-blind, randomized protocol, resistance-trained males were matched for strength and placed into one of three groups: protein (PRO), PRO-CHO, or the same PRO-CHO supplement (1.5 g x kg(-1) body weight x d(-1)) containing CrM (Cr-PRO-CHO) (0.1 g x kg(-1) body weight x d(-1)). Assessments were completed the week before and after a 10-wk structured, supervised RE program: strength (1RM, three exercises), body composition (DEXA), and vastus lateralis muscle biopsies for determination of muscle fiber type (I, IIa, IIx), cross-sectional area (CSA), contractile protein, and creatine content.
Cr-PRO-CHO provided greater improvements in 1RM strength. At least 40% of the strength improvements could be attributed to hypertrophy of muscle involved in this exercise. Cr-PRO-CHO also resulted in greater increases in LBM, fiber CSA, and contractile protein compared with PRO and PRO-CHO.
In RE-trained participants, supplementation with Cr-PRO-CHO provided greater muscle hypertrophy than an equivalent dose of PRO-CHO, and this response was apparent at three levels of physiology (LBM, fiber CSA, and contractile protein content).
在抗阻运动（RE）训练期间，关于将力量和瘦体重（LBM）的增加归因于一水肌酸（CrM）的研究并未同时评估这些变化与细胞和亚细胞适应性。此外，很少将CrM治疗组与接受氮和能量相似的安慰剂组进行比较。本研究的目的是比较含CrM的蛋白质 - 碳水化合物（PRO - CHO）补充剂与含相似氮和能量的补充剂对RE训练期间身体成分、肌肉力量、纤维特异性肥大和收缩蛋白积累的影响。
在一项双盲、随机方案中，将经过抗阻训练的男性按力量进行匹配，并分为三组之一：蛋白质（PRO）组、PRO - CHO组或相同的PRO - CHO补充剂（1.5 g×kg⁻¹体重×d⁻¹）加CrM（Cr - PRO - CHO）（0.1 g×kg⁻¹体重×d⁻¹）。在为期10周的结构化、有监督的RE计划前后一周完成评估：力量（1RM，三项运动）、身体成分（双能X线吸收法）以及股外侧肌活检以确定肌纤维类型（I型、IIa型、IIx型）、横截面积（CSA）、收缩蛋白和肌酸含量。
Cr - PRO - CHO组在1RM力量方面有更大改善。至少40%的力量提升可归因于参与该运动的肌肉肥大。与PRO组和PRO - CHO组相比，Cr - PRO - CHO组在LBM、纤维CSA和收缩蛋白方面也有更大增加。
在经过RE训练的参与者中，补充Cr - PRO - CHO比等量的PRO - CHO能提供更大的肌肉肥大，并且这种反应在生理的三个层面（LBM、纤维CSA和收缩蛋白含量）都很明显。
