Cycling on hot summer days

How the heat affects your body during endurance sports

In endurance sports, temperature plays a huge and often underestimated role. An increased body temperature caused by heat in combination with physical exertion and the additional loss of fluids and minerals from sweat all have negative effects on performance.

Good to know: Believe it or not, you can train your body to have better thermoregulation – at least, to a certain extent. Trained athletes are able to sweat more than untrained cyclists with the same increase in core body temperature. Other differences: The sweat of well-conditioned athletes contains less sodium and other minerals, and skin circulation is usually much better thanks to good heat acclimatisation.

Better performance through regular training in high temperatures

The best way to prepare for competitions and races in summer is to regularly train in high temperatures. Advantages: The performance-inhibiting effect of heat can be somewhat mitigated, and training leads to an increase in plasma volume. Since blood volume has direct effects on oxygen transport in the body and thus on maximum oxygen uptake, increased plasma volume can also be beneficial during competitions at normal temperatures.

"For high-intensity training sessions at the height of summer, it makes sense to wait for the somewhat more pleasant temperatures in the morning or evening. In high temperatures, you cannot perform at the same level you’re used to. So the intensity and quality of the training intervals are going to suffer. Relaxed basic training sessions, on the other hand, can specifically and strategically be done in higher temperatures, which lets you benefit from the positive effects of heat adaptation," says sports scientist Simon Gessler.

Cooling off

Since the body’s core temperature has a direct influence on performance, it’s important to come up with a system for cooling the body during competitions in high temperatures. The simplest means: cold drinks. They cool you off from the inside but – even beyond that – a dehydrated body tends to overheat more quickly, and fluid intake prevents this. Pouring water over your body and your cycling jersey also provides a pleasant cooling effect.

A gentle warm-up before races

The difficulty in getting ready for a competition is to bring your muscles up to operating temperature before the start. At the same time, it’s vital to not let your core body temperature climb too high. On hot days, a relaxed warm-up session is perfect for that. In addition, you should cool down your upper body and arms – the muscle groups that do not have a direct influence on propulsion. That’s why, in professional road cycling, you’ll commonly see athletes use a cooling vest in preparation for time trials.

The difference between time trials and marathons: For short and intense time trials, it’s particularly important that your performance muscles are warmed up and have good blood flow right from the beginning. In long marathons with a neutralised start, you can make do without warming up, which also prevents you from reaching a high body temperature too early.