模拟全程马拉松跑过程中能量代谢的变化

目的:了解优秀运动员在全程马拉松跑过程中通气量、摄氧量(V·O2)、潮气量、心率、总能耗、糖消耗量、脂肪消耗量以及乳酸产生量等的变化。方法:以1名肯尼亚优秀马拉松运动员为实验对象,在跑步机上以接近于其80%最大摄氧量(V·O2max)强度的18 km·h^-1速度完成全程马拉松跑,并在全过程中通过运动心肺测试系统采集能量代谢相关指标,并与3天前进行的V·O2max测试获得相关指标的最大值进行对比。结果:1)在马拉松过程中,单位时间内的V·O2、通气量、潮气量相对稳定,平均值分别占递增速度V·O2max测试中最大值的75.4%、67.0%、81.0%;2)在不补充水分时,心率从第40 min开始出现逐渐上升的趋势,结束时心率达到最大心率的92.5%,全程平均心率为最大心率的88.8%;3)全程每公斤体重的每公里能耗基本保持稳定,呼吸商在0.9~1.0之间,能量供应以糖的有氧代谢为主,乳酸产生量极少,糖和脂肪消耗总量为8.4 g·kg^-1和0.5 g·kg^-1;4)从静脉血部分指标的变化来看,红细胞总数及其参数变化幅度较小,白细胞总数、单核细胞数以及粒细胞数的增加幅度分别达到了100.9%、142.7%和186.1%。结论:优秀马拉松运动员在全程马拉松跑过程中,动作经济性能够保持相对稳定,补水不足时心率呈上升趋势,能量供应主要以糖的有氧代谢为主,乳酸产生量极少。运动前后红细胞数变化较小,白细胞等免疫相关细胞的变化较大。

The Variation of Energy Metabolism during a Simulated Marathon Run

Objective:To understand the variance of ventilation volume,oxygen uptake,tidal volume,heart rate,total energy consumption,carbohydrate and fat consumption,lactic acid production of elite athletes in the course of marathon running were examined so as to provide references for deep understanding of this event.Methods:An excellent Kenya marathon athlete was chosen as the subject.A full marathon run was completed on the treadmill at 18 km·h^-1 which was about his 80%V·O2max.Energy metabolism related indicators were collected during the whole process by exercise cardiopulmonary test system and compared with the maximum of the corresponding indicators obtained at V·O2maxtest 3 days ago.Results:1)During the marathon,oxygen uptake,ventilation volume and tidal volume per unit time were relatively stable,with the average value accounting for 75.4%,67.0%and 81.0%respectively of the maximum measured in the V·O2maxtest with increasing speed;2)without drinking water,the heart rate increased gradually from the 40 thmin,and reached 92.5%of the maximum heart rate at the end.The average heart rate during the whole process was 88.8%of the maximum heart rate;3)the energy consumption per kilometer per kilogram of body weight throughout the whole process remained stable,with the respiratory quotient between 0.9 and 1.0.The energy supply was dominated by the aerobic metabolism of carbohydrate,very little lactic acid was production,and the total consumption of carbohydrate and fat was 8.4 g·kg^-1 and 0.5 g·kg^-1 of body weight;4)according to the changes of venous blood indexes,the changes of the total number of red blood cells and their parameters were small,while the total number of white blood cells,mononuclear cells and granulocytes increased by 100.9%,142.7%and 186.1%respectively.Conclusion:Excellent marathon runners could maintain relatively stable movement economy during the whole marathon run,and their heart rate tended to rise when they were short of water.Their energy supply was mainly dominated by the aerobic metabolism of carbohydrate.The production oflactic acid was very little.The changes of erythrocyte number before and after exercise were small,while the changes of immune-related cells such as white blood cells were large.