Training in the heat: How to maintain your performance in the height of summer
It’s eleven o’clock in the morning, the tarmac is shimmering, and the run that felt as light as a feather back in June has you completely knackered after just twenty minutes today. Your heart rate is ten beats higher than usual, yet your pace still isn’t right, and somewhere between kilometres four and five you find yourself wondering whether you’ve simply got worse over the summer. You haven’t. Your body is simply performing two tasks at once – and that takes its toll.
How heat affects your circulation
As soon as the temperature rises, your skin acts as an air-conditioning system. The body directs a significant proportion of the blood to the skin’s surface to release heat – blood that is then no longer available to the working muscles. Your heart compensates for this by beating faster. That’s why your pulse is higher at the same pace: it’s not a sign of poor fitness, it’s physics. Added to this is sweat, which depletes not only fluids but also electrolytes – and the more both levels drop, the tougher every repetition and every kilometre becomes.
Anyone who stubbornly trains to a set pace or with their usual weights in the height of summer is therefore training against their own body. The smarter way to gauge your effort during these weeks is by your heart rate or simply how you feel: the same level of effort rather than the same numbers. The numbers will come back of their own accord in September.
The good news is: your body adapts to the heat
The amazing thing about the summer heat is how quickly the body adapts to it. After around ten to fourteen days of regular training in warm temperatures, it increases its blood plasma volume, starts sweating earlier and more efficiently, and loses less salt in the process. You’ll really notice the difference: your heart rate drops again, the same route feels easier, and, as an added bonus, you’ll benefit from an effect that endurance athletes specifically aim to harness – heat acclimatisation works in a similar way to gentle altitude training and pays dividends even on cooler days.
Until then, the simple things help: schedule intense sessions for the early morning or late evening, when the air and ground are still cool. Drink before, during and after training – for longer or more strenuous sessions, include electrolytes, not just plain water. And take seriously any signs that go beyond normal sweating: dizziness, goosebumps despite the heat, or a sudden cessation of sweating are the moment when you should stop the session.
Water will be your training partner
The most elegant solution to the heat is to move your training to a place where you won’t overheat in the first place. In the height of summer, swimming is perhaps the very best endurance workout there is: the water keeps you cool whilst your heart and lungs are working at full capacity. Aqua fitness is also considerably more intense than its reputation suggests – the water’s resistance challenges your muscles without putting excessive strain on your joints or circulation. If you combine both with a refreshing strength session in the morning, you’ll stay surprisingly fit throughout the hot weeks.
THE FLAG Costa del Sol in Estepona shows just what this can feel like: There, the training day begins in the gym with a sea view or with one of the daily rotating sessions ranging from yoga to Pilates to HIIT; at midday, you can cool off in the heated seawater pool or straight in the sea; and anyone who takes recovery seriously can then opt for cold and red light therapy. Training in the heat is no exception there – it’s the concept, on 320 days of sunshine a year.
Perhaps, in the end, the heat is an honest trainer: it forces you to listen to your body rather than the clock. Anyone who practises this for a whole summer will take a skill into the autumn that is more valuable than any personal best in July.