There’s no need to quit running when the temperature soars. By taking a few precautions, you can head out into the heat – you may even benefit.

Most runners are familiar with hot weather warnings:

• Avoid sunburn
• Watch out for heat exhaustion
• Keep your head covered 
• Stay hydrated

The risks are very real. But are there any advantages of exercising in the heat?

1. Your fitness will only benefit if you adapt gradually

Your body has to work harder to run in hot weather and there is some evidence that, once you acclimatise, this may lead to increased fitness. However, you will only benefit if you adapt to the heat gradually, over seven to ten days.

2. Never attempt a hard one-off run in the heat 

Experts agree that you should never head out for a long, hard one-off run in the burning heat – no matter how appealing the weather looks. It will likely do you more harm than good, triggering heat illness and putting strain on your heart and body.

3. Slow down your pace to 70% of your usual effort 

However, if you slow down the pace to 70 per cent of your usual effort and go for just a short run to begin with – gradually adding pace and time each day – you may start to reap some fitness benefits. 

Slow down the pace to 70 per cent of your usual effort and go for just a short run to begin with.

4. Matters of the mind

There are mental benefits to summer running, too. For starters, running in the heat when the weather is good makes you feel better. It’s a double whammy of the release of your body’s natural endorphins, coupled with the well-documented mood-boosting and vitamin D-enhancing properties of sunshine.

Anecdotal evidence also suggests you may be less likely to injure yourself in hot weather – but don’t push it. However, take sensible precautions or any benefits will be surpassed by injury, sunburn, electrolyte imbalance and dehydration.

5. Body benefits

Heat training leads to physiological changes that help you acclimatise, so running in the heat becomes easier and safer. Your body gradually produces more blood plasma and the total volume of blood increases. Blood, with its oxygen and micronutrients, is flushed more easily into your muscles and organs. You will also sweat sooner.

The increased blood volume means the heart can pump blood more easily and your body is more efficient at cooling itself. A study from the University of Innsbruck, Austria, published in the Journal Of Sports Science & Medicine says this increased plasma volume ‘normally results in enhanced aerobic performance’ as less viscous blood improves circulation and delivers more oxygen to working muscles. 

However, the jury is out on how long any performance benefits might last. The immediate effects of acclimatisation that enable you to run in hot weather fade after seven to 14 days. However, many runners swear that a summer of heat training has more lasting fitness effects that will see them run better throughout autumn and winter. 

6. Hydrate without over-hydrating 

You should also slow your pace if you’ve not already trained for the heat. Also keep hydrated, but not overhydrated to the point where you risk hyponotraemia, a dangerous condition where your mineral balance is dangerously out of kilter. It’s best to drink an electrolyte sports drink. 

If you'd like to find out more, check out our Expert Guide to Hydration.

7. Don't forget suncream and a cap or visor 

And remember, always apply some sun cream, stay hydrated and protect the top of your head when the weather heats up. A cap or visor is great for warding off the sun’s rays, keeping you cooler and preventing you from overheating.