Summer fitness, holidays and hydration

When the days get longer and the sun starts to beat down, it doesn’t matter if you’re home or abroad, working out suddenly takes a back seat. So how do you stick to your goals – and make sure you don’t get injured – when it’s baking hot out?
If you’re looking to make it through to autumn without a summer’s worth of cocktails and barbecue kilos to show for it, you’re in the right place; we’ve caught up with celebrated personal trainer Matt Roberts for a no-nonsense guide…

Myth-busting time: is it good or bad for you to workout when it’s hot?

“It’s hard to make a blanket statement regarding exercise in the heat, as it’ll affect different people in different ways. Things like age, training status, body weight, sweat rate and ethnicity will all play a role in how someone tolerates hot weather conditions. The main things to be mindful of, though, are hydration status and skin protection from the sun.

“Assuming you’re looking to do 30-60 minutes of exercise, you can pre-hydrate with the following beforehand:

  • 500ml of fluid on the night before exercise
  • 500ml in the morning
  • 500 to 1,000ml, one hour before exercise
  • 250 to 500ml, 20 minutes before exercise

“In reality, summer is often the perfect time to be exercising. With longer, drier and finer weather, there’s more reason and opportunity to get out and move more. So why not use the summer as reason to maintain or increase your training, and keep the emphasis on outdoor activities?

“The good news is there’s no reason to stray too far from your usual training regime when it’s hot. As long as you remain mindful of your hydration status and aim to exercise outside of the hottest parts of the day then the ‘best’ workout you can do is often simply the one that gets done.”


How hot is too hot?

“Generally, if outdoor temperatures start to exceed 32-35 degrees [Celsius], it might be better to head for an air-conditioned gym rather than training outside.

“It’s also advisable to be mindful of humidity levels, as this can impact the body’s ability to cool down through the evaporation of sweat. Anything above 75% humidity alongside a high outdoor temperature is worth avoiding.”


What about working out on holiday?

“Most summer holidays will mean more time spent out in the sun so it might be advisable to use your exercise as a way of having a break from the outdoors. If in a hot country, then it’s often a good idea to find an air-conditioned gym, or even workout in your hotel room.

“Here’s a good option for working out in your hotel room:

“Most gyms will look to maintain a room temperature of around 19 degrees, so you could use this as a general rule; in most of the summer months, early morning will offer those kind of favourable conditions.”

So there you go, the keys to summer workout success are: Stick to the mornings, aim for 19 degrees as optimal temperature, and make sure you’re drinking enough water. Now get out there! You can find more of Matt’s expertise at

Get more from your workouts… Find out how to improve your inbuilt levels of motivation.