Chwalbińska-Moneta J, Kaciuba-Uściłko H, Krysztofiak H, Ziemba A, Krzemiński K, Kruk B, Nazar K
Department of Applied Physiology, Polish Academy of Sciences, Warsaw.
J Physiol Pharmacol. 1998 Sep;49(3):433-41.
The aim of this study was to follow up the electromyographic activity (EMG) of dynamically working muscles with simultaneous determinations of blood lactate and plasma catecholamine concentrations during progressive exercise. Twenty eight male soccer players aged 20.6 +/- 0.8 yrs performed incremental bicycle ergometer exercise test. The test consisted of 3-min stages exercise separated by 1-min rest intervals. Work load at each stage increased by 50 W until volitional exhaustion. The root mean square (rms)-EMG activity of the rectus femoris and soleus muscles were recorded continuously during exercise. Venous blood samples were taken after each exercise stage for determination of blood lactate (LA). Additionally in seven subjects adrenaline (A) and noradrenaline (NA) concentrations were determined. The EMG activity increased negligibly during exercise of low to moderate intensities revealing an abrupt rise at the load corresponding to thresholds of blood lactate and plasma catecholamine accumulation (LA-T, A-T, NA-T). Close correlations (P < 0.001) were found between blood LA concentration and EMG derived from rectus f. (r = 0.72) and soleus (r = 0.68) muscles. The mean threshold exercise intensities for m. rectus f. and m. soleus EMG (176 +/- 9 W and 172 +/- 9 W, respectively) did not differ significantly from lactate (164 +/- 7 W), noradrenaline (178 +/- 6 W) and adrenaline (180 +/- 5 W) thresholds, all of them detected by log-log transformation. The results indicate that threshold character of EMG changes in dynamically working muscles reflects to some extend the patterns of blood lactate and plasma catecholamine changes during incremental exercise.
本研究的目的是在进行递增运动期间，通过同时测定血乳酸和血浆儿茶酚胺浓度，来追踪动态工作肌肉的肌电图活动（EMG）。28名年龄在20.6±0.8岁的男性足球运动员进行了递增式自行车测力计运动测试。测试由3分钟的运动阶段组成，各阶段之间有1分钟的休息间隔。每个阶段的工作量增加50瓦，直至自愿疲劳。在运动过程中持续记录股直肌和比目鱼肌的均方根（rms）-EMG活动。在每个运动阶段后采集静脉血样以测定血乳酸（LA）。另外，在7名受试者中测定了肾上腺素（A）和去甲肾上腺素（NA）的浓度。在低至中等强度运动期间，EMG活动增加可忽略不计，而在对应血乳酸和血浆儿茶酚胺积累阈值（LA-T、A-T、NA-T）的负荷时出现突然上升。发现血LA浓度与股直肌（r = 0.72）和比目鱼肌（r = 0.68）的EMG之间存在密切相关性（P < 0.001）。股直肌和比目鱼肌EMG的平均阈值运动强度（分别为176±9瓦和172±9瓦）与乳酸（164±7瓦）、去甲肾上腺素（178±6瓦）和肾上腺素（180±5瓦）阈值相比无显著差异，所有这些阈值均通过对数-对数转换检测到。结果表明，动态工作肌肉中EMG变化的阈值特征在一定程度上反映了递增运动期间血乳酸和血浆儿茶酚胺变化的模式。
