Hot Weather Training - Safely and Efficiently

Whether training or racing, you want to be safe and efficient.

Being safe involves guarding against the danger of heatstroke and being able to react to it should it occur.

Training efficiently is about training in a way that makes best use of your time.


A few simple precautions are really all that are needed, but do read the note at the end of this section:

  • You must start out adequately hydrated. This does not mean swallowing huge quantities of water just before you start (this can cause a condition called hyponatremia which itself is dangerous). Simply make sure you are properly hydrated, the best way to do this is to compare your urine colour to the chart shown n the link: Urine Colour
  • Make sure your urine stays in the right range during the hours before you run. It also makes sense to use suitable salt tablets in the water.
  • It also makes sense to have access to water, but if you are out for less than about an hour, you shouldn’t need to drink providing you started out properly hydrated. You simply cannot sweat that much in an hour.
  • If you are going to be out longer, you should take water with you, once again laced with suitable salts.
  • Start drinking this early in small quantities, every 15 minutes is a pretty good guide.
  • If you are taking water with you, buy a belt that holds a bottle. Running with one of those strange hand-held bottles will wreck your technique.
  • Start cool – don’t sunbath and then go for a run – best start from an air-conditioned room or car.
  • Wear loose-fitting clothing – preferably white – and consider a cap or visor
  • Keep the intensity low, you are out to get the body to adapt, not break records.
  • Where possible run in the shade – In the sun the temperature can effectively be 10 – 15 degrees higher than the actual air temperature
  • Run with a buddy if possible, at the very least let somebody know your route and expected time of return.


Heatstroke is unpredictable. Taking basic precautions reduces the danger to negligible proportions. However, I have seen a National Cross Country Champion hit by it. He was taking part in a non-running event on a hot, but not excessively hot, day with others who were far less fit. He succumbed to the extent of cardiac arrest. He survived because there were people knew what needed to be done, kept his heart going and got him to hospital.

  • We repeat “Run with a buddy if possible, at the very least let somebody know your route and expected time of return.”

Efficient training

A session in the heat is designed to help you acclimatise. It is not designed to improve speed, endurance or anything else.

The biggest threat to your performance is an interruption to your training. We lose fitness faster than we can gain it. For that reason we should finish a heat adaptation session ready to repeat it the following day (if we should get the opportunity in a British summer).

Make sure you start out properly fuelled. You will burn more calories in the heat and you will be using your glycogen stores.

If you are out for more than an hour take some top up food with you. In normal conditions your glycogen stores will last you about two hours but you will deplete them faster in the heat.

Keep the intensity of the session low. The benefit of any training session is limited by the speed at which the body can make the adaptations it is designed to produce. Doing more than the body can respond to is counter-productive and acclimatisation changes take place more slowly than normal training adaptations.

Refuel and rehydrate properly after the training session. Drink small quantities frequently till your urine returns to an acceptable colour. Eat a protein and carb rich snack (about 20 grams of protein) within about 20 minutes of finishing.