The men’s FIFA World Cup finals in North America this summer may well haved proved to have been the hottest on record. That’s why at England’s training camp in Girona, Spain, last summer, heated tents were used to simulate the extreme conditions players would likely encounter across the US, Mexico and Canada.
You don’t have to be an elite sportsperson to be affected by extreme heat. Research into the efforts of gardeners revealed that
a three-hour session of weeding, digging, raking and carrying materials expended up to 1,000 calories. Even walking burns around 300 calories an hour. For both activities, heat can increase heart rate by 10–15bpm and energy expenditure by around 10–15%.
The harder you work, the hotter your core becomes and the more you sweat. That’s why a bespoke hydration plan has been devised for each England player’s training. You don’t need to be quite so militant, but you should still heed expert advice. “Simply drinking to thirst works well when intensity and duration aren’t too intense,” says Sam Shepherd, head of sports science at Precision Fuel & Hydration.
“That said, sweat rate still climbs rapidly in hot weather even when you’re not running around a football pitch, so keeping a bottle of water to hand and not waiting until you feel parched is a smart habit – particularly as thirst cues can diminish with age .”
Salt is important, too, says Shepherd: “If you’ve been out for a few hours in real heat, a salty snack will help you rehydrate more effectively than water alone.”
Sodium helps transfer water to your cells. The more you sweat, the more sodium you lose and the faster fatigue sets in. To replenish your sodium levels, eat a salty snack or pop an electrolyte tablet into your water. A clear bottle allows you to monitor how much you’ve drunk. Sip instead of slug – you’ll absorb more.
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Polyester is the material of choice for sport tops: it’s wonderful at wicking moisture away from your skin to help it evaporate, reducing the build-up of sweat (and the risk that your top becomes a drenched rag). Merino wool is another excellent sweat-wicking option. Avoid cotton, which traps moisture.
You might also consider adapting your behaviour, most importantly planning to tackle your main exertions for the cooler parts of the day – early in the morning or later in the evening. During a long hot spell lasting for weeks, you’ll find that you can handle lengthier periods in the heat as your mind and body gradually become acclimatised to higher temperatures.
You might have seen footballers swilling peppermint around their mouths (before spitting it out). Research shows that mint triggers your body’s cold receptors, creating an instant cooling sensation.
Finally, don a sun hat with a full, wide brim.
Sweat tests
Precision Fuel & Hydration offers both in-person sweat tests and a free online assessment to help you understand your individual sodium losses. precisionhydration.com
