What to Eat and Drink for Hot Weather Exercise

This is a good research-backed article on fueling and hydration in hot weather, something that we’ll be seeing soon. (And which will become all the more prevalent in the future with climate change.)

A few takeaways:

  • Mild dehydration doesn’t impair exercise performance—you have to lose more than 2% of your body weight before you slow down.

  • Stored sugar in your liver and muscles can last for only about 70 minutes, so fueling is necessary for events longer than an hour. But don’t take sugar more than 5 minutes before starting or the rise in blood sugar can trigger an insulin response that actually drops blood sugar levels.

  • Salt (but not potassium, calcium, or magnesium for most) is the only mineral that’s necessary and mostly in events lasting over 3 hours. Sports drinks probably don’t have enough, so salty foods are better. When my sister was doing triathlons, her coach gave her salt tablets, which are an easy way to get a fair amount without tasting it.

  • Don’t drink too much—hyponatremia (too dilute salt levels) is a real thing and can result in confusion, seizures, unconsciousness, and even death.