When summer arrives, the same recommendations are repeated: avoid the hottest hours of the day, seek shade and drink water. This is sound advice, especially during heatwaves, but it does not always correspond to reality. Some people enjoy working out, sweating, running, or cycling outdoors. (In France, during extreme heat, the Ministry of Health recommends limiting physical activity as much as possible and favoring gentle activities. Simple actions can help avoid accidents, its services insist. Find its advice on sports practice during heat peaks.)
Is this possible? Yes, but the heat adds an additional load and requires you to adapt your effort. It’s not the same thing to go out for a half-hour walk as to do a series of runs, a long bike ride or an intense weight training session. The risk and necessary adaptations depend on the person, the type of exercise performed and the duration of exposure to heat.
The same workout is no longer quite the same
During physical activity, muscles generate heat. To dissipate it, the body sends more blood to the skin and activates perspiration, while continuing to fuel the muscles. This is why a usual pace can be more demanding in summer: the perception of effort increases, fatigue occurs earlier and performance can decrease.
You should pay attention to your feelings, your breathing, your heart rate and your ability to recover between efforts.
Adapting your training does not mean being less fit. Running more slowly, reducing the number of sets or extending rest times can require similar effort to a more intense session in cool weather. On hot days, the timer or training load doesn’t always reflect everything. You should also pay attention to your feelings, your breathing, your heart rate and your ability to recover between efforts.
Sweating helps, but it’s not an end in itself
Sweating is one of the main mechanisms the body uses to release heat, but what really cools us is the evaporation of sweat on the skin. When humidity is high, you can find yourself soaked and, despite this, cool down less well.
Additionally, sweating more does not mean training better, burning more fat, or eliminating more “toxins.” It depends on temperature, humidity, clothing, intensity and individual adaptation. This is why it is not very relevant to evaluate a session based on the degree of humidity of the t-shirt at the end of the exercise: this can be an indicator of the effort made, but also simply of heat, humidity or a poor choice of clothing.
It is helpful to start the session by being well hydrated. But drinking in excess (“just in case”) is not a good idea.
Another aspect to take into account is that heat tolerance is acquired through training: gradual exposure improves the ability to sweat and regulate body temperature. A beginner should therefore favor shorter sessions, at moderate intensity, and times when it is cooler. A trained and acclimatized person, on the other hand, has more room for maneuver, but is not invulnerable: he can reduce the pace during endurance exercises and reduce the volume or lengthen the rest times during strength training sessions.
Eat and drink sensibly
Exercising strenuously immediately after a large meal can cause a feeling of heaviness, nausea or digestive problems. It is advisable to leave sufficient time or, if time is limited, to opt for light and easy-to-digest foods, such as fruit, toast with honey or jam, yogurt or a small simple sandwich. The amount and timing should be tailored to the type of training and individual tolerance.
It is also helpful to start the session well hydrated. For a short session, water is generally sufficient, but if the effort is prolonged or if sweating is profuse, it may be useful to also replenish your reserves of mineral salts and carbohydrates.
In any case, drinking in excess (“just in case”) is not a good idea: hydration must be adapted to the duration and intensity of the effort, as well as to individual losses. A good rule of thumb is to arrive at training not very thirsty and observe how the body reacts afterwards: excessive fatigue, a headache or an unusually slow recovery can be signs that the session, heat or hydration have not been managed well.
Training in direct sunlight adds additional stress
Some people like to feel the sun while they work out. This preference should not be demonized, but it should be understood that solar radiation increases the thermal load and leads to additional exposure to ultraviolet rays.
It is therefore possible to train in hot weather. The main thing is not to prove what you are capable of, but to progress, to listen to your body and to adapt your program.
If you choose to exercise under the sun’s rays, it is advisable to protect your skin, wear light clothing, have water on hand and accept that on some days you may need to reduce the duration or intensity of exercise. The World Health Organization (WHO) recommends limiting exposure during hours when radiation is most intense and using shade, protective clothing and sun protection.
Some symptoms should not be ignored: if you experience dizziness, severe headache, nausea, unusual weakness, loss of coordination, confusion or feeling faint, you should stop, find a cool place and refresh your body.
It is therefore possible to train in hot weather. The main thing is not to prove what you are capable of, but to progress, to listen to your body and to adapt your program. Let’s start with the hill; then, if all goes well, Everest will come by itself.
