Wellness & Nutrition Science Institute, Morinaga Milk Industry Co., Ltd., Zama, Kanagawa-Pref. 252-8583, Japan.
Laboratory for Exercise and Environmental Physiology, Faculty of Education, Niigata University, Niigata, Niigata-Pref. 950-2181, Japan.
Nutrients. 2020 Mar 24;12(3):867. doi: 10.3390/nu12030867.
Food ingestion has been shown to affect thermoregulation during exercise, while the impact of protein degradant consumption remains unclear. We investigated the effects of casein hydrolysate ingestion on thermoregulatory responses during exercise in the heat. In a randomized, placebo-controlled, double-blind, crossover trial, five men and five women consumed either 5 g of casein hydrolysate or placebo. Thirty minutes after ingestion, participants cycled at 60% VOmax until voluntary exhaustion wearing a hot-water (43 °C) circulation suit. Exercise time to exhaustion, body core temperature, forearm sweat rate, and forearm cutaneous vascular conductance did not differ different between the conditions. However, chest sweat rate and mean skin temperature increased upon casein hydrolysate ingestion compared with placebo during exercise. Increased chest sweat rate upon casein hydrolysate ingestion was associated with elevated sudomotor sensitivity to increasing body core temperature, but not the temperature threshold for initiating sweating. A positive correlation was found between chest sweat rate and plasma total amino acid concentration during exercise. These results suggest that casein hydrolysate ingestion enhances sweating heterogeneously by increasing peripheral sensitivity of the chest's sweating mechanism and elevating skin temperature during exercise in the heat. However, the physiological link between plasma amino acid concentration and sweat rate remains unclear.
进食已被证明会影响运动时的体温调节，而蛋白质降解产物的摄入的影响尚不清楚。我们研究了摄入酪蛋白水解物对热环境中运动时体温调节反应的影响。在一项随机、安慰剂对照、双盲、交叉试验中，五名男性和五名女性分别摄入 5 克酪蛋白水解物或安慰剂。摄入后 30 分钟，参与者穿着热水（43°C）循环服以 60% VOmax 的速度进行自行车运动，直至自愿力竭。两种情况下的运动至力竭时间、核心体温、前臂出汗率和前臂皮肤血管传导性没有差异。然而，与安慰剂相比，在运动过程中摄入酪蛋白水解物会增加胸部出汗率和平均皮肤温度。摄入酪蛋白水解物后胸部出汗率增加与增加的核心体温引起的出汗敏感性增加有关，而不是出汗的温度阈值。在运动过程中，还发现胸部出汗率与血浆总氨基酸浓度之间存在正相关。这些结果表明，酪蛋白水解物的摄入通过增加胸部出汗机制的外周敏感性并在热环境中运动时升高皮肤温度，从而不均匀地增强出汗。然而，血浆氨基酸浓度与出汗率之间的生理联系尚不清楚。
