Diet Myths, Debunked: Exercising in the Heat Burns More Calories

The sweltering weather is here. Does this mean that you should be exercising at high noon is best in order to burn more calories? Let’s examine this myth and see what it’s all about.


People on treadmills in gym

Photo by: Jupiterimages ©(C) 2008 Jupiterimages

Jupiterimages, (C) 2008 Jupiterimages

The sweltering weather is here. Does this mean that you should be exercising at high noon in order to burn more calories? Let’s examine this myth and see what it’s all about.

Does Temperature Matter?

Many hard-core dieters are looking for a quick fix to lose weight. One question that has spawned is the temperature — does working out in hot weather help burn more calories as opposed to working out in an air conditioned room? I’ve seen people tie bags to their legs to help them sweat more (or wear rubber suits) or exercise during the hottest time of the day because they believe it’ll help melt  more fat.

The Facts

Many folks find they weigh less after exercising in the heat. But chalk that up to dehydration (and loss of water weight). As soon as you gulp down the necessary fluids and rehydrate, the scale will readjust.

It’s also important to note that exercising in the heat is potentially dangerous and can lead to heat-related illness. It doesn’t take long for dehydration to kick in. Signs include loss of energy, dizziness, cramps, headaches and unusual fatigue. Symptoms can become more extreme if precautions aren’t taken.

Exercising Safely In the Heat

Here are some important tips to remember when exercising in the heat.

  • Start hydrated: It’s important to be hydrated before beginning to exercise.
  • Drink up: Fluid needs are higher because you’re sweating more. As such, it’s important to keep your water bottle close by.
  • Try a sports drink: Sports drinks like Gatorade have carbohydrates that help fuel muscles and replenish electrolytes that are lost through sweat.
  • Exercise early or late in the day: Exercise when the weather is coolest – typically in the morning or evening.
  • Dress appropriately: Forgo the rubber suits and keep cool by wearing light and loose fighting clothing.

The Bottom Line: Exercising in the heat doesn’t help you more lose weight and can be very dangerous. Exercise smart by staying hydrated and keeping as cool as possible.

Toby Amidor, MS, RD, CDN, is a registered dietitian and consultant who specializes in food safety and culinary nutrition. See Toby's full bio »

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