Heat is Hard on the Heart

We're experiencing a heat wave in Melbourne! How does training in hot weather affect your heart?

On a hot day, blood flow is rerouted so more of it goes to your skin surface to help your body let off your internal heat (and you break a sweat). The redirection of blood flow to the skin makes less oxygen available to your muscles and hence your heart beats faster and pumps harder to compensate for the loss of oxygen going to your muscles. This results in a higher heart rate for your usual set training pace, and you tend not to maintain the same pace that you would on a cooler day.

So, if you wear a heart rate monitor, don't be too bothered by a higher heart rate during a workout that might feel slower than usual. When training in the heat, it is better to train or run by feel or Perceived Exertion level rather than pace or time.

Medications can interfere with your body's heat regulation. Beta blockers slow the heartbeat and thereby limit the body's ability to circulate blood fast enough for heat exchange at the skin's surface. Diuretics increase urine output and so can worsen dehydration.

Be aware of your own health status when training in the warmer weather. Modify your training appropriately. Enjoy summer. Look after your #hearthealth.

Check out these 10 steps for making hot weather tolerable.