Abstract:
Thermogenesis is well understood, but the relationships between cold water immersion (CWI), the post-CWI rewarming and the associated physiological changes are not. This study investigated muscle and systemic oxygenation, cardiorespiratory and hemodynamic responses, and gastrointestinal temperature during and after CWI. 21 healthy men completed randomly 2 protocols. Both protocols consisted of a 48 minutes heating cycling exercise followed by 3 recovery periods (R1-R3), but they differed in R2. R1 lasted 20 minutes in a passive semi-seated position on a physiotherapy table at ambient room temperature. Depending on the protocol, R2 lasted 15 minutes at either ambient condition (R2_AMB) or in a CWI condition at 10°C up to the iliac crest (R2_CWI). R3 lasted 40 minutes at AMB while favoring rewarming after R2_CWI. This was followed by 10 minutes of cycling. Compared to R2_AMB, R2_CWI ended at higher V ˙ O2 in the non-immersed body part due to thermogenesis (7.16(2.15) vs. 4.83(1.62) ml.min-1.kg-1) and lower femoral artery blood flow (475(165) vs. 704(257) ml.min-1) (p < 0.001). Only after CWI, R3 showed a progressive decrease in vastus and gastrocnemius medialis O2 saturation, significant after 34 minutes (p < 0.001). As blood flow did not differ from the AMB protocol, this indicated local thermogenesis in the immersed part of the body. After CWI, a lower gastrointestinal temperature on resumption of cycling compared to AMB (36.31(0.45) vs. 37.30(0.49) °C, p < 0.001) indicated incomplete muscle thermogenesis. In conclusion, the rewarming period after CWI was non-linear and metabolically costly. Immersion and rewarming should be considered as a continuum rather than separate events.
摘要:
产热是众所周知的,但是冷水浸泡(CWI)之间的关系,CWI后复温和相关的生理变化没有。这项研究调查了肌肉和全身氧合,心肺和血液动力学反应,以及CWI期间和之后的胃肠道温度。21名健康男性随机完成2个方案。两种方案都包括48分钟的热循环锻炼,然后是3个恢复期(R1-R3)。但它们的R2不同.R1在环境室温下在物理治疗台上以被动半坐姿持续20分钟。根据协议,R2在环境条件下(R2_AMB)或在CWI条件下在10°C下持续15分钟,直至Ii骨(R2_CWI)。R3在AMB处持续40分钟,同时有利于在R2_CWI之后复温。这之后是10分钟的循环。与R2_AMB相比,由于产热,R2_CWI在未浸入的身体部位中处于较高的V•O2(7.16(2.15)与4.83(1.62)ml。min-1.kg-1)和下股动脉血流(475(165)与704(257)ml。min-1)(p<0.001)。只有在CWI之后,R3显示了一个渐进的减少在肌和腓肠肌内侧O2饱和度,34分钟后显著(p<0.001)。由于血流与AMB方案没有区别,这表明身体浸入部分的局部产热。在CWI之后,与AMB相比,恢复循环时的胃肠道温度较低(36.31(0.45)与37.30(0.49)°C,p<0.001)表明肌肉热生成不完全。总之,CWI后的复温期是非线性的,代谢昂贵.沉浸和复温应被视为连续体,而不是单独的事件。