Gálvez J M, Alonso J P, Sangrador L A, Navarro G
Instituto de Ergonomía MAPFRE SA, 50639 Zaragoza, Spain.
J Appl Physiol (1985). 2000 Feb;88(2):487-92. doi: 10.1152/jappl.2000.88.2.487.
The purpose of this study was to determine the effect of muscle mass and the level of force on the contraction-induced rise in heart rate. We conducted an experimental study in a sample of 28 healthy men between 20 and 30 yr of age (power: 95%, alpha: 5%). Smokers, obese subjects, and those who performed regular physical activity over a certain amount of energetic expenditure were excluded from the study. The participants exerted two types of isometric contractions: handgrip and turning a 40-cm-diameter wheel. Both were sustained to exhaustion at 20 and 50% of maximal force. Twenty-five subjects finished the experiment. Heart rate increased a mean of 15.1 beats/min [95% confidence interval (CI): 5.5-24.6] from 20 to 50% handgrip contractions, and 20.7 beats/min (95% CI: 11.9-29.5) from 20 to 50% wheel-turn contractions. Heart rate also increased a mean of 13.3 beats/min (95% CI: 10.4-16.1) from handgrip to wheel-turn contractions at 20% maximal force, and 18.9 beats/min (95% CI: 9. 8-28.0) from handgrip to wheel-turn contractions at 50% maximal force. We conclude that the magnitude of the heart rate increase during isometric exercise is related to the intensity of the contraction and the mass of the contracted muscle.
本研究的目的是确定肌肉质量和力量水平对收缩诱导的心率升高的影响。我们对28名年龄在20至30岁之间的健康男性进行了一项实验研究（功效：95%，α：5%）。吸烟者、肥胖受试者以及那些进行超过一定能量消耗的定期体育活动的人被排除在研究之外。参与者进行了两种等长收缩：握力和转动直径40厘米的轮子。两者均以最大力量的20%和50%持续到力竭。25名受试者完成了实验。从握力收缩的20%到50%，心率平均增加15.1次/分钟[95%置信区间（CI）：5.5 - 24.6]，从轮子转动收缩的20%到50%，心率平均增加20.7次/分钟（95%CI：11.9 - 29.5）。在最大力量的20%时，从握力收缩到轮子转动收缩，心率也平均增加13.3次/分钟（95%CI：10.4 - 16.1），在最大力量的50%时，从握力收缩到轮子转动收缩，心率平均增加18.9次/分钟（95%CI：9.8 - 28.0）。我们得出结论，等长运动期间心率增加的幅度与收缩强度和收缩肌肉的质量有关。
