The Do's And Dont's Of Working Out In The Australian Heat

31/12/2015 9:56 AM AEDT | Updated 15/07/2016 12:51 PM AEST
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Athletic woman stretching

With large swathes of Australia sweltering through a record breaking heatwave, just the thought of training outdoors is enough to get you sweating.

But there's no need to shelve your outside workout through summer as long as you take the right precautions -- and in some cases, training under a hot sun can even boost your performance.

The Huffington Post Australia chatted to Sydney-based exercise physiologist Dr Bill Sukala and personal trainer Simon Margheritini on how to get the most out of a sizzling outdoor workout.

Burning calories v exercise fatigue

Sukala said one advantage of training in hot weather is that you burn more calories, but he said that benefit can be offset because you fatigue faster.

"It is true that you probably burn a few extra calories exercising in the heat, that sounds great on the surface but the other side of it is when you're exercising in hotter temperatures your body core temp goes up."

According to the American Council on Exercise, a warm but not extreme temperature is best for burning fat and exercising longer, so that more calories are burned overall.

"The inherent limitation is you won't be able to exercise as long. That's the trade off," Sukala said.

"If you adjust it for time you'll probably burn more calories in the short term but you won't be able to exert yourself for as long."

Acclimatisation effect

Another positive from training in heat is what Sukala calls the "acclimatisation effect".

"There will be positive changes in your body's physiology which make you better able to compete and perform."

workout heat

Working out in hot weather can be good for you, but there are risks

"Your body experiences physiological changes associated with acclimatising to that hot weather."

The Australian Sports Commission said that the benefits of acclimatisation on the body include:

  • a lower heart rate at a given heat and exercise stress level

  • better maintenance of core body temperature

  • reduction in the sweating threshold

  • increased distribution of active sweat glands

  • increased sweat rate

  • an increased sweating sensitivity to increasing core body temperature

  • a reduction in the loss of water and electrolytes from the kidneys

The risks

While there are positives, the AIS also warns that working out in heat conditions poses risks to the body.

"Exercising in hot, humid conditions when the body is not accustomed to it can place the body under great stress," the commission said.

Sukala agrees, pointing to hyperthermia as a risk from going too hard in the heat.

"That can actually compromise performance particularly with things like muscular endurance ... long duration activities like cycling, or rugby and football when you're going non-stop for a extended period of time."

"People need to keep that in mind that if they're exercising at really high intensities in very hot temperatures and a relatively high humidity," Sukala said.

Hydration is key

Go and Get Fit's Margheritini said hydration is key to ensure training in extreme heat is not counterproductive.

"Overheating in the hot weather is not a good thing."

"When you sweat and your core temperature overheats ... the oxygen used is being used to sweat, not for aerobic conditioning, so the more you overheat you'll find you fatigue quicker."

workout heat

Drinking lots of fluids is crucial when training in heat

"You don't get the same exercise effect as you do in an environment where you're not overheating."

He said it was important to remember that weight loss resulting from training in extreme heat was from your body shedding water, not from burning fat.

He said it was possible to lose up to three litres of water from a workout in hot weather, which was not at all healthy.

"For anyone who wants to lose weight it's a definite no-no."

According tothe AIS that hypohydration -- total body water below normal -- damages exercise performance due to an increased body temperature, higher heart rate, extra fatigue and reduced mental function.

Hit the pool

A good option for hot weather training is to get to the pool, Margheritini said.

He said a particularly good exercise is pool running, running on the spot in the pool, and swimming while holding your breath under water.

workout pool

Swimming laps and pool running are good hot weather exercises

"You go under water, push off the wall and go as far as you can under water holding your breath, then swim back," Margheritini said.

"That's really great to open up the lungs."

He adds that if you are trading the gym for the pool don't forget the sunscreen.

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