Rawson E S, Clarkson P M
Department of Exercise Science, University of Massachusetts, Amherst 01003, USA.
Int J Sports Med. 2000 Jan;21(1):71-5. doi: 10.1055/s-2000-8859.
The hypothesis of this study was that short term creatine (Cr) ingestion in older individuals would increase body mass and exercise performance, as has been shown in younger subjects. Seventeen males 60-78 years old were randomly placed into two groups, Cr and placebo (P), and supplemented in double-blind fashion for 5 days. Subjects ingested either 5 g of Cr plus 1 g of sucrose 4x per day or 6 g of a sucrose placebo 4x per day. Isometric strength of the elbow flexors was assessed using a modified preacher bench attached to a strain gauge. Isokinetic exercise performance was assessed using an intermittent fatigue test of the knee extensors. Subjects performed 3 sets of 30 repetitions with 60 sec rest between sets. There was a small (0.5 kg) but statistically significant increase in body mass (p < 0.05) in the Cr group after supplementation. There was a significant overall interaction between groups in isokinetic performance from pre to post supplementation (group x time x set, p < 0.05). However, analysis of the groups separately revealed that the subjects in the Cr group demonstrated a small non-significant increase in isokinetic performance while subjects in the P group demonstrated a small non-significant performance decrement. There was no significant difference in isometric strength between groups from pre to post supplementation. These data suggest that acute oral Cr supplementation does not increase isometric strength and only produces small increases in isokinetic performance and body mass in men over the age of 60.
本研究的假设是,与年轻受试者的情况一样,老年个体短期摄入肌酸(Cr)会增加体重并提高运动表现。17名年龄在60 - 78岁的男性被随机分为两组,即肌酸组(Cr)和安慰剂组(P),并以双盲方式补充5天。受试者每天4次摄入5克肌酸加1克蔗糖,或每天4次摄入6克蔗糖安慰剂。使用连接应变仪的改良牧师椅评估肘屈肌的等长力量。使用膝关节伸肌的间歇性疲劳试验评估等速运动表现。受试者进行3组,每组30次重复,组间休息60秒。补充后,Cr组的体重有小幅(0.5千克)但具有统计学意义的增加(p < 0.05)。补充前后,两组在等速运动表现方面存在显著的总体交互作用(组×时间×组次,p < 0.05)。然而,分别对两组进行分析发现,Cr组的受试者等速运动表现有小幅但不显著的增加,而P组的受试者表现有小幅但不显著的下降。补充前后,两组在等长力量方面没有显著差异。这些数据表明,急性口服补充肌酸不会增加等长力量,且在60岁以上男性中只会使等速运动表现和体重有小幅增加。