Exercising in hot weather puts added stress on the body, as it responds to the overload placed on it. To cool itself, your body will send out more blood to circulate through your skin, which in turn leaves less blood for the muscles, and increases heart rate and therefore blood pressure.
The imposed stress can also cause hyperthermia, deyhdratation, deteriotated physical and mental performance, and exertional heat illness – which can even be fatal.
But don't be scared into dropping your fitness regime and slumping into a deck chair with a Calippo instead (although feel free to do that afterwards). There are a number of simple steps you can take to ensure you don't overheat like a broken oven.
1. Avoid midday sun
Let's kick off with a no-brainer, shall we? If the temperature is forecast to hit 20-plus, plan to exercise before 11am or after 6pm, or you'll bake yourself.
2. Know your limits
You may be feeling uplifted by the sunlight and inspired by all the other exercisers out in the park, but this is not the time to push yourself beyond your limits. Boundary-testing is for nippier weather.
3. Wear lightweight clothes
Don't go out there like you're Rocky in a training montage
Don't go out there in a hoodie like you're Rocky in a training montage. Choose loose-fitting, breathable fabrics that are light in colour (ideally white), as this will help to reflect heat.
And if you're in the park, you might want to avoid wearing yellow, as it can attract flying insects.
4. Have a drink...
If you're exercising in short bursts – circuit training for example – sipping on water should be adequate. If exercising for a sustained period in excess of an hour, however, a sports drink containing salt and potassium will aid in keeping your fluid levels just right.
5. ...and keep on drinking
A pint of water immediately after your workout won't be sufficient, as you're still sweating. You'll need to sip water throughout the day to keep your hydration levels in check.
6. Pick the right sun cream
High SPFs can interfere with the skin's ability to thermally regulate itself
Sun cream will obviously protect your skin from getting burned, but go for SPF 15 or lower if possible, as high SPFs can interfere with the skin's ability to thermally regulate itself. Also, go for a non-oil based sun cream, so that it doesn't sweat off. There are sun creams available that are specifically designed for sports.
There's nothing wrong with exercising in the sun, you just need to be careful and look after yourself. If in any doubt, complete your workout alongside someone else so that you can keep an eye on each other.
Now have fun with that frisbee!