Cognitive, psychomotor, and physical performance in cold air after cooling by exercise in cold water

Introduction: This study evaluated performance after lowering core temperature at different rates while local tissues were either cooled (lower body) or not cooled (upper body). Methods: There were 10 men who volunteered to perform up to 8 cold water immersions (CWI) at combinations of 2 water temperatures (10 degrees C and 15 degrees C), 2 depths waist (W), chest (C)], and 2 walking speeds (0.44 or 0.88 m center dot s(-1)) until their core temperature fell to 35.5 degrees C, stabilized above that temperature, or they requested to stop. They also completed a control trial (120 min rest in 19 degrees C air). Immediately following each CWI and control, cognitive and physical performance tests were performed in cold air (11 C; CAE). Results: Overall, the CWI protocol lowered rectal temperature by 0.3-1.0 degrees C. Mean skin temperature was similar to 26 degrees C and finger temperature was similar to 15 degrees C during CAE. No statistical differences were observed across trials for any cognitive test. On the physical performance tests, step test performance was degraded similar to 12% on CWI trials compared with control, but there were no differences in manual dexterity, hand grip strength, marksmanship, or pull-ups. Conclusions: These results, indicate that cognitive performance can be maintained despite mild hypothermia, and that physical performance is related to local tissue temperature, not a moderately reduced core temperature.