Bundling up for winter sports is a no brainer, but how many of us take the same amount of time to dress when we’re just exercising in the cold? Research from the University of Tsukuba, Japan, points out that even when doing routine exercise, you should be paying attention to the temperature—because your perception isn’t.
The body can perceive changes in core temperature and reacts with subconscious mechanisms like sweating or shivering to control temperature, but the brain also relies on behaviors that cause actions to avoid overheating by moving inside or seeking warmth when too cold. When exercising, you lose the valuable ability to notice swings in your core body temperature and react with these behavioral changes.
Exercise complicates these inner thermoregulatory mechanisms, especially when cold weather is added to the mix. Cold weather leeches the heat out of exercising muscles which would normally be retained and sweating still occurs during cold weather leading to a further loss of heat. These contributing factors, plus the release of endorphins which numbs the skin’s ability to sense its temperature accurately, and it’s easier to lose enough heat to cross over into hypothermia.
To investigate these facts further, the research team explored if exercise was affecting core body temperature or skin temperature with healthy young men performing a low-intensity exercise in a pool of cold water. There was no change in the skin temperature (which researchers assume was because of the low intensity of the exercise), but core temperature was impacted.
When at rest, it’s easier for the brain and body to sense hypothermia; but when exercising, this ability is significantly impaired. It’s a good reminder for those who are exercising in the cold to treat it with as much respect as when you exercise in the heat, and actively take steps to limit exposure to cold just like you’d limit exposure to the heat.
Tomomi Fujimoto, Naoto Fujii, Kohei Dobashi et al. Effects of low-intensity exercise on local skin and whole-body thermal sensation in hypothermic young males. Physiology & Behavior, 2021; 240: 113531 DOI: 10.1016/j.physbeh.2021.113531