Human Physiological Performance During a 1 Mile Swim in Cold Water

Abstract

Human physiological responses to cold water swimming (≤5°C) are poorly characterized. A database (www.internationaliceswimming.com) describes 1 mile ice swimming performance times and swim conditions. This study analyzed data from 71 male and 17 female persons who completed 1 mile ice swims. Swim completion time was 33.9 ± 6.0 minutes for males and significantly slower for females at 36.2 ± 7.8 minutes. Increased age for females may be associated with a more robust increase in swim times relative to males whose swim times were less detrimentally affected by increasing age. A subset of swimmers completed multiple 1 mile swims (n=24), and the second swim time was significantly faster than the first, although improvements were not observed for additional swims. Cold exposure from increasing wind chill has been suggested to have a detrimental effect on cold water swim time, and was associated with an increased swim time that approached significance (P = 0.06). Water temperatures below 50C had no statistically significant effect on swim completion time. In summary, ice swimming is increasing in popularity with consideration for future Winter Olympic activities. Characterization of ice water exposure physiology remains an important consideration for emergency, military, and medical personnel. This data set provides a useful benchmark for understanding and predicting physiological performance during exposure to cold environmental conditions.