Bishop David, Ruch Nicole, Paun Vanessa
School of Human Movement and Exercise Science, UWA, Australia.
Med Sci Sports Exerc. 2007 May;39(5):872-9. doi: 10.1249/mss.0b013e318031b026.
Team sports contain high-intensity sprints separated by active recovery (AR) and passive recovery (PR). The beneficial effects of AR on repeated-sprint performance, for short exercise duration, in thermoneutral environments, are well known. However, team sports are often performed in hot environments for prolonged periods. Therefore, the aim was to investigate the thermal strain of AR versus PR during prolonged, intermittent-sprint exercise.
Eight men performed two intermittent-sprint tests in the heat (35 degrees C, 44% relative humidity (RH)), with either AR or PR.
No differences were found between conditions for mean work (AR: 3739.5 +/- 204.7 J; PR: 3814.0 +/- 161.3 J) or power per sprint (AR: 1257 +/- 64 W; PR: 1245 +/- 47 W). AR was associated with a significantly higher heart rate (HR), muscle (Tmu), rectal temperature (Tre), body temperature (Tb), and skin temperature (Tsk) after 7, 10, and 25 min, respectively. Body heat storage, and physiological and cumulative heat-strain indices, were significantly higher in AR compared with PR. The differences in Tmu and thermoregulatory strain between AR and PR were greater than the differences in Tre and Tb.
These results likely can be attributed to a greater rate of whole-body heat loss during the AR protocol. Because AR has previously been associated with a greater muscle pump, a greater blood flow to surface veins and inactive musculature may have been maintained, allowing greater heat dissipation than during PR, when blood was likely to be pooling in the legs. Despite the greater increase in body temperature and heat strain in AR than in PR, there was no difference in performance, possibly because critical temperature levels were not reached in this study.
团体运动包含高强度冲刺，其间穿插主动恢复（AR）和被动恢复（PR）。在热中性环境中，短运动时长下AR对重复冲刺表现的有益影响已为人熟知。然而，团体运动通常在炎热环境中长时间进行。因此，本研究旨在探讨在长时间间歇性冲刺运动中AR与PR的热应激情况。
8名男性在高温环境（35摄氏度，相对湿度44%）下进行了两次间歇性冲刺测试，分别采用AR或PR。
在平均功（AR：3739.5±204.7焦耳；PR：3814.0±161.3焦耳）或每次冲刺功率（AR：1257±64瓦；PR：1245±47瓦）方面，两种条件之间未发现差异。在7分钟、10分钟和25分钟后，AR分别与显著更高的心率（HR）、肌肉温度（Tmu）、直肠温度（Tre）、体温（Tb）和皮肤温度（Tsk）相关。与PR相比，AR的身体蓄热以及生理和累积热应激指数显著更高。AR和PR之间Tmu和体温调节应激的差异大于Tre和Tb的差异。
这些结果可能归因于AR方案期间全身热量散失速率更高。由于AR此前与更大的肌肉泵相关，可能维持了流向体表静脉和不活动肌肉组织的更大血流量，从而比PR期间（此时血液可能在腿部淤积）有更大的散热。尽管AR中体温和热应激的增加幅度大于PR，但表现上没有差异，可能是因为本研究未达到临界温度水平。
