PHYSIOLOGICAL-RESPONSES TO PROLONGED EXERCISE IN ULTRAMARATHON ATHLETES
PHYSIOLOGICAL-RESPONSES TO PROLONGED EXERCISE IN ULTRAMARATHON ATHLETES
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DOI：
10.1152/jappl.1986.61.2.611
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发表时间：
1986-08-01
影响因子：
3.3
通讯作者：
THOMPSON, MW
中科院分区：
文献类型：
--
作者：
DAVIES, CTM;THOMPSON, MW
研究人员对 10 名超级马拉松运动员在最高强度水平下持续 4 小时的长时间运动的生理反应进行了检查。 4 小时运动的能量消耗为 14,146 .+-。 1,789 kJ，其中 63% 由脂肪氧化提供。血浆游离脂肪酸升高，但血乳酸浓度(Δ0.2 mmol/l)和交换比(Δ0.05)变化较小，股外侧肌运动后糖原含量(130±42μmol/g)估计为正常静息值的37-53%。运动期间，从第 50 分钟到第 240 分钟，O2 摄入量 (.ovrhdot.VO2) 随着时间的推移而增加，在工作 110 分钟后增加变得显着 (P < 0.01)。 .ovrhdot.VO2 的变化相当于相对强度 (%.ovrhdot.VO2max) 上升 +9.1% 以及速度变化 1.49 km/h。心率的上升补偿了每搏输出量（SV）的下降，从而维持了心输出量，并且直肠温度（Tre）（Δ0.63℃）和出汗量（3.49±0.50kg，相当于体重的5.5％）的增加以及平均皮肤温度（hivin.Tsk）（-1.22℃）的降低在运动期间都在可忍受的范围内。运动后，股四头肌产生随意力的能力丧失（-25%），但肌肉的电诱发机械特性保持不变。结果表明，热因素和心血管因素都不会限制长时间（4 小时）的运动，尽管利用脂肪作为燃料的能力对于超长距离运动员可能很重要。 .DELTA..ovrhdot.VO2 可能是随意肌无力的结果，反映了纤维募集的增加。
The physiological responses of 10 ultramarathon athletes to prolonged exercise at the highest intensity level they could sustain for 4 h have been examined. Energy expenditure for the 4 h of exercise was 14,146 .+-. 1,789 kJ, of which 63% was provided by the oxidation of fat. Plasma free fatty acids rose, but the changes in blood lactate concentration(.DELTA.0.2 mmol/l) and exchange ratio (.DELTA.0.05) were small, and the postexercise glycogen content (130 .+-. 42 .mu.mol/g) of the vastus lateralis muscles was estimated to be 37-53% of normal resting values. During exercise O2 intake (.ovrhdot.VO2) increased with time from the 50th to 240th min, the rise becoming significant (P < 0.01) after 110 min of work. The change in .ovrhdot.VO2 was equivalent to a rise in relative intensity (%.ovrhdot.VO2max) of +9.1% and a change of speed of 1.49 km/h. A rise in cardiac frequency compensated for a fall in stroke volume (SV), so that cardiac output was maintained, and the increases in rectal temperature (Tre) (.DELTA.0.63.degree. C) and sweat loss (3.49 .+-. 0.50 kg, equivalent to 5.5% of body wt) and the decreased mean skin temperature (.hivin.Tsk) (-1.22.degree. C) were within tolerable limits during exercise. Following exercise there was a loss (-25%) of ability to generate voluntary force of the quadriceps femoris, though electrically evoked mechanical properties of the muscle remained unchanged. The results suggest that neither thermal nor cardiovascular factors are limiting to prolonged (4 h) exercise, although the ability to utilize fat as a fuel may be important in ultradistance athletes. The .DELTA..ovrhdot.VO2 may be a consequence of voluntary muscle weakness and reflect an increased fiber recruitment.