Effect of Four Weeks Repetitive Mild Cold Water Immersion on Thermoregulatory Responses during Immersion and Civd Response

Previous studies have reported about the changes in thermoregulatory responses due to cold adaptation, and several types of cold adaptation (insulative, metabolic and hypothermic adaptation) have been described (Bittel, 1987; Tipton et al., 2008). The differences in cold exposure and physical characteristics have been considered as the factors affecting different types of adaptation. However it has remained uncertain that the relationship between the cold adaptation type and factors affecting adaptation. Besides the whole body cold adaptation, there have been studies about peripheral cold adaptation as a cold induced vasodilatation (CIVD) in finger immersed in cold water. It was generally found that the cold adapted subjects had a more pronounced CIVD responses (Daanen, 2003; Geurts et al., 2006). It is considered that further investigation was needed to clarify the relationship between the changes in CIVD responses and whole body thermoregulatory responses after a cold acclimation. There is a possibility that the CIVD response might be one of the cold acclimation parameters affecting the thermoregulatory responses related to cold acclimation types. This study investigated the effects of 4 weeks repetitive mild cold water immersion on the thermoregulatory responses during immersion and CIVD responses during finger cold water immersion. Additionally, another purpose was to clarify the factors affecting the different cold acclimation types.