The Surprising Benefits of Exercising on a Hot Day

There’s nothing like a hot day to empty a gym.

As the heat rises, exercise levels drop.

And when people DO manage to stick with their exercise habits, it’s done so with the invariable complaints about the weather. We get it, a hot day gives you something to talk about, but there’s a way we can reframe this conversation.

Before we talk about the benefits of exercising in the heat, it’s valuable to understand why exercising on a hot day is so much more difficult.

You see, there’s only so much blood to go round. On a hot day, we need to send blood to our skin so the evaporation of sweat can remove heat from our body. And when we exercise we need to send blood to our muscles to provide fuel and remove waste. When exercising on a hot day, there’s competition between these two needs. Eventually, blood flow to the skin wins, with our body prioritising a healthy temperature.

The competition between the skin and the muscles is the reason for the added discomfort we experience when exercising in the heat.

Of course, exercise in the heat can be dangerous, and we’re not for a moment suggesting it should be a ‘free-for-all’, but we do believe this can be viewed as an opportunity. Here’s why.

Research has revealed some surprising benefits of exercising in the heat:

  • Cyclists who trained in the heat increased their speedĀ at normal temperatures by 6% when compared to those who trained in normal temperatures.
  • The same cyclists had 5% increases in both aerobic and anaerobic power.
  • There were 9% increases in cardiac output (the volume of blood pumped by the heart) in heat-trained athletes.

The reasons for these positive effects of heat-training come back to increases in blood plasma. You’ll remember that exercising in the heat creates competition between the skin and the muscles for blood. To combat this competition, our body increases blood plasma, meaning there’s more blood to go round, and less competition.

So while we have to show an extra degree of care on a hot day, maybe it’s worth reframing how we perceive it – shifting it from something to complain about, to an opportunity to improve.

Dan Williams

Dan Williams


Dan Williams is the Director of Range of Motion and leads a team of Exercise Physiologists, Sports Scientists, Physiotherapists and Coaches. He has a Bachelor of Science (Exercise and Health Science) and a Postgraduate Bachelor of Exercise Rehabilitation Science from The University of Western Australia, with minors in Biomechanics and Sport Psychology.