Thermoregulatory and Immune Responses During Cold Exposure: Effects of Repeated Cold Exposure and Acute Exercise

摘要

Whether or not the thermoregulatory system fatigues (i.e., causes blunted shivering thermogenesis and vasoconstriction) during cold exposure is unknown. Thus, a series of experiments were executed to determine if serial cold water immersion or acute exertional fatigue would cause thermoregulatory fatigue during subsequent cold exposure. This information will be used in developing thermoregulatory models during cold exposure. During these studies several unanswered questions regarding thermoregulation in the cold were also addressed: (1) do thermoregulatory responses to cold show fatigue when prolonged cold water exposures are serially repeated. (2) are thermoregulatory effector responses to cold affected by time of day. (i.e., circadian influences); (3) does a single acute, fatiguing exercise bout impair thermoregulatory responses to subsequent cold exposure. and (4) does fatigue induced by severely strenuous physical activity compromise the immune response to cold exposure. The results of these studies suggest that: (1) serial cold water blunts shivering leading to lower core temperatures, (2) thermoregulatory effector responses are not affected by time of day, (3) exercise increases peripheral heat loss and lowers core temperature during subsequent cold exposure, and (4) that acute cold exposure has immununostimulating effects.