Nothing in life quite compares to lying on your kitchen floor, covered in sweat, basking in post-run bliss. At first you feel exhausted, but then a sense of accomplishment and tranquility washes over you. Bask in your own perspiration and glory for too long, though, and you’re destined to experience a violent shiver and chills.
According to John Martinez, medical director of the U.S. Paralympic triathlon team, this physical deep freeze has to do with your core body temperature. “While exercising, your body’s temperature increases and the small blood vessels on the surface of the skin dilate, or open wider, to release heat through the skin. The body also starts sweating to help reduce this increase of your body’s core temperature,” he explains. “When you stop running, the core temperature will start to drop, but you may still be trying to lose heat through the dilated blood vessels near the skin as well as continued sweating.”
To that end, he adds, “runners with larger surface areas may notice this effect more since they’re losing more heat.”
No matter how big or small, any runner who rests on the floor for 10 minutes after a run is throwing that cooling process into overdrive. When that happens, Martinez says, your core temperature drops so quickly that your body “may induce shivering to bring the core temperature back up to normal.”
In order to avoid such chills, Martinez highlights the importance of a proper post-run cooldown. That is, instead of coming home from a run and getting distracted by work or enticed by the comfort of your couch, “walk for 15 to 20 minutes and change into dry clothes.” Once you’ve given your body time to naturally cool down on its own, take a cold shower.
A much more temperate post-run bliss is sure to follow.