Hile Amy M, Anderson Jeffrey M, Fiala Kelly A, Stevenson J Herb, Casa Douglas J, Maresh Carl M
University of Connecticut, Storrs, CT, USA.
J Athl Train. 2006 Jan-Mar;41(1):30-5.
Theoretically, the risk of compartment syndrome is increased during creatine monohydrate (CrM) supplementation because of intracellular fluid retention in muscle cells and the overall increased size of the muscle tissue. Whether this change in intracellular fluid is associated with an increase in anterior compartment pressure in the lower leg when subjects are under thermal stress is unknown.
To assess the influence of CrM on the resting and postexercise anterior compartment pressure of the lower leg in mildly to moderately dehydrated males exercising in the heat.
Double-blind, randomized, crossover design.
Human Performance Laboratory.
Eleven well-trained, non- heat-acclimated, healthy males (age = 22 +/- 2 years, height = 181.1 +/- 7 cm, mass = 78.4 +/- 4.2 kg, V(O2)max = 50.5 +/- 3.4 mL.kg(-1).min(-1)).
INTERVENTION(S): Subjects were supplemented with 21.6 g/d of CrM or placebo for 7 days. On day 7, they performed 2 hours of submaximal exercise, alternating 30 minutes of walking with 30 minutes of cycling in the heat, resulting in approximately 2% dehydration. This was followed by an 80-minute heat tolerance test (temperature = 33.5 +/- 0.5 degrees C, humidity = 41.0 +/- 12%), which included 12 repetitions of a 3-minute walk (pace = 4.0 +/- 0.1 miles/h, intensity = 37.1 +/- 6.1% V(O2)max) alternating with a 1-minute, high-intensity run (pace = 11.8 +/- 0.4 miles/h, intensity = 115.0 +/- 5.6% V(O2)max), resulting in an additional 2% decrease in body weight.
Before supplementation and on day 7 of supplementation, anterior compartment pressure was measured at rest, after dehydration, and at 1, 3, 5, 10, 15, and 60 minutes after the heat tolerance test. Analysis of variance with repeated measures was calculated to compare differences within the trials and time points and to identify any interaction between trial and time.
The CrM intake was associated with an increase in body weight (P < .05). A moderate effect size was noted for compartment pressures between the trials for the differences between predehydration and postdehydration (eta2 = 0.414). This effect diminished substantially by 3 minutes after the heat tolerance test. Compared with the placebo trial, the change in anterior compartment pressure from rest to dehydration was greater, as was the change from rest to 1 minute after the heat tolerance test (P < .05) during the CrM trial.
A 7-day loading dose of CrM increased anterior compartment pressures after dehydration and immediately after the heat tolerance tests, but the changes did not induce symptoms and the pressure changes were transient.
从理论上讲，补充肌酸一水合物（CrM）期间发生骨筋膜室综合征的风险会增加，这是因为肌肉细胞内的细胞内液潴留以及肌肉组织整体尺寸增大。尚不清楚当受试者处于热应激状态时，这种细胞内液的变化是否与小腿前骨筋膜室内压力升高有关。
评估CrM对在高温环境下轻度至中度脱水的男性进行运动时小腿休息时和运动后前骨筋膜室内压力的影响。
双盲、随机、交叉设计。
人体运动实验室。
11名训练有素、未适应热环境的健康男性（年龄=22±2岁，身高=181.1±7厘米，体重=78.4±4.2千克，最大摄氧量=50.5±3.4毫升·千克⁻¹·分钟⁻¹）。
受试者连续7天每天补充21.6克CrM或安慰剂。在第7天，他们进行了2小时的次最大强度运动，在高温环境下，30分钟步行和30分钟骑行交替进行，导致约2%的脱水。随后进行80分钟的耐热性测试（温度=33.5±0.5摄氏度，湿度=41.0±12%），其中包括12次3分钟步行（步速=4.0±0.1英里/小时，强度=37.1±6.1%最大摄氧量）与1分钟高强度跑步（步速=11.8±0.4英里/小时，强度=115.0±5.6%最大摄氧量）交替进行，导致体重额外下降2%。
在补充前以及补充第7天，分别在休息时、脱水后以及耐热性测试后1、3、5、10、15和60分钟测量前骨筋膜室内压力。计算重复测量方差分析，以比较试验和时间点内的差异，并确定试验和时间之间的任何相互作用。
摄入CrM与体重增加相关（P<.05）。对于脱水前和脱水后差异的试验间骨筋膜室内压力，观察到中等效应量（η²=0.414）。这种效应在耐热性测试后3分钟时大幅减弱。与安慰剂试验相比，在CrM试验期间，从休息到脱水时前骨筋膜室内压力的变化更大，从休息到耐热性测试后1分钟时的变化也更大（P<.05）。
7天加载剂量的CrM在脱水后和耐热性测试后立即增加了前骨筋膜室内压力，但这些变化未引发症状，且压力变化是短暂的。
