Exercising in the Heat: These 5 Facts Impact Your Workout

There is a lot of speculation about the positive effect of exercising in the heat. First the good news: yes, you burn more calories when you work out in the heat. 

To help you understand why and what you should know, we’ve put together some facts on the topic.

Fact 1: The higher your body temperature, the more calories you burn

As the outdoor temperature rises, so does your body temperature. Your system then has to work harder to cool the body down to a normal temperature. More strain is put on your lungs and heart as a result of the hot conditions, and since the body has to work harder, it burns more calories.(1)

Fact 2: Changes in temperature affect calorie burn

When you work out in the heat, your body tries to maintain an average temperature of 36°C.(2) With every variation in temperature, you burn more calories to compensate for the fluctuations. This energy is drawn from excess calories and fat reserves.

Fact 3: Your body sweats to cool off

Your body’s natural cooling system kicks in when you work out in higher temperatures. You start producing more sweat to release the heat and reduce your body temperature. The sweat on your skin evaporates, which keeps your body temperature within a healthy range.


…increased sweat production does not necessarily mean higher calorie burn. If you don’t sweat very much, you still burn as many calories as your heavily sweating workout partner.

Most people don’t like to sweat, but without the body’s natural temperature regulation, our performance would drop even more. If you start sweating right at the beginning of your workout, it doesn’t always mean that you are out of shape. Your body has learned to start cooling down early. That’s why well-trained athletes start sweating faster than others. 

Fact 4: Your basal metabolic rate influences your calorie burn

You burn more energy through the combination of heat and exercise. That is the good news. But this is not just because of the temperature — your basal metabolic rate also plays a role here. This depends on factors like age, weight, and height and varies from person to person.

Good to know:

The higher a person’s basal metabolic rate, the more calories he or she will burn. 

You can change your BMR by building muscle mass, which then burns more calories and speeds up your metabolism. Functional bodyweight training is a great way to do this.

Get out there…

…and take advantage of the beautiful weather!
In the summertime, most of us automatically burn more calories, because we move more when the weather is nice. Plus, when it’s hot outside we don’t usually feel like eating rich, high calorie meals.

Fact 5: Exercising in the heat has risks

Working out in the heat might get you a nice tan, but it also has some risks. Heat and humidity can make the body feel exhausted quickly. Stop working out the moment you experience any dizziness, signs of exhaustion, or nausea. Look for a shady spot to rest and drink some water. Give your body time to adjust to the heat. This also applies for workouts and runs on vacation

Key points:

  1. Make sure you drink enough liquids.  
  2. Wear breathable clothing during your workout.
  3. Look for shady places to exercise outdoors. 
  4. Don’t push yourself too hard in the blazing heat. Go easy on your body.
  5. Whenever possible, workout early in the morning or in the evening when it’s cooler outside.

As simple as it may sound at first, the only way to burn more calories — and, therefore, fat — when you exercise is by intensifying your workout no matter the weather. But when it’s hot outside, make sure you implement our tips for exercising in the heat.


Tom Koscher As a personal trainer and running coach, Tom loves to inspire and challenge others with creative workout ideas. He simply cannot resist fitness challenges. Tom's motto is: why walk when you can run? View all posts by Tom Koscher