Using Deliberate Cold Exposure for Health and Performance

The group trained by Hof were able to control their heart rate, temperature, and immune response, and stimulate the sympathetic system. This practice of heavy breathing along with regular cold exposure was later discovered to release the stress hormones adrenaline, cortisol, and norepinephrine on command. The burst of adrenaline gave heavy breather

If the thought of being even remotely chilly makes you reach for the nearest blanket, take comfort: the more we expose ourselves to cooler temperatures, the more health benefits we stand to gain. And these benefits increase even as we mentally adapt to the cooler temperatures.

What this suggests is that performing brief periods of exercise in either cold or hot ambient temperature may accelerate the brain benefits of exercise—a potential win for both the efficiency junkies and those with limited mobility.