A mercury approaching 40 degrees for several days. The suffocating heat has become common and puts the body to work. To maintain its internal temperature at 37 degrees, it implements an adaptation mechanism called thermoregulation: blood vessels dilate, the heart works harder (increases cardiac output) to pump blood, send a larger volume of plasma to the skin and evacuate heat through sweating. The sweat, as it evaporates, cools the body.
When you do sports in hot weather, this cooling process is in full force, because in addition to managing the adaptation to the hot air of the environment, the body must manage the evacuation of the heat related to the exercise. Cardiac effort increases especially to increase sweating. In these conditions, overheating is possible with the risk of heat stroke and heart problems. The warning signs are recognized: headache, cramps, nausea, mental confusion, heat syncope, heat exhaustion.
Certain profiles, such as those over 60 years old, especially those suffering from chronic diseases or under medical treatment, are particularly exposed to these risks: the cardiovascular system is less efficient, the sensation of thirst is altered and sweating disorders are possible (the sweat glands work less well).
Read more > Because the heat becomes more difficult to bear with age
The heat also limits strength levels. A set of parameters that should not be taken lightly during the exercise, if we want to avoid this “pressure cooker” effect. Even more if you are inactive or sedentary, observe Anael Aubrysports scientist and doctor in exercise physiology. “A healthy person over 60 and already active will physiologically have more capacity to manage heat and therefore to limit the increase in internal temperature when it is hot,” he explains.
Sports and heat: practice quickly and at a low intensity
If you are in good health, in good physical condition and already trained (do not start a sport during a heat wave), physical activity is not contraindicated when it is hot… Under certain conditions. Concretely, we adjust our practice: we obviously avoid training in direct sunlight and at the hottest times (between 12 o’clock and 4 o’clock or even until the evening in the summer when the thermometer will only go down at the end of the night). We prefer cool places, shaded corners and we prefer to exercise in the morning at cooler hours.
Read more > Is it a good idea to drink salt water in hot weather?
What types of sports should you favor during the heat wave?
Let’s leave aside very cardio disciplines like running to favor gentler activities, specifies the former researcher at theNational Institute of Sport, Expertise and Performance (Insep). What do we do for example? “We avoid intensity and go for example towards muscle work, soft gymnastics work, mobility work, balance work, Pilates, yoga, walk quietly… Any low-intensity activity that slightly engages the cardiac system limits the risks related to heat. It will increase the plasma volume, promote the ability to sweat and limit the increase in internal temperature.”
If you like weight training, consider lightening the load compared to usual by making sure that the cardio increases a little. How do you place the cursor? Whatever the activity, you must be able to speak without being out of breath. Conversely, if you feel out of breath, if you are gasping for air, it means that the heart rate is too high.
What are the good reflexes to protect yourself from the heat while playing sports?
The best possible adaptation to the heat during exercise requires some usual precautions, which the coach of Olympic and professional athletes explains to us in detail.
Shorter train
We also shorten the duration of our training. “The longer the session, the more heat stress and intensity increase.” Start with about twenty minutes and, if all goes well, increase by 5 minutes each session. As soon as you warm up, take your foot off the gas. “Instead of 15 minutes of warm-up, we broke it to do 3 times five minutes of mobility interspersed with recovery, advises Anaël Aubry. And during the session, do not hesitate to lower the intensity to ensure that the internal effort is linear and controlled.”
Keep yourself hydrated enough
Remember that you should drink between 1.5L to 2L of water per day to increase your ability to sweat, avoid mineral loss and prevent dehydration (common in the elderly). During exercise and throughout the day, drink water regularly, without waiting to be thirsty, to build reserves. We diversify the intake of water: syrup diluted in water, fruit juices, mineral waters (for example Rozana, Saint-Yorre), cold soups, fruit compotes, sorbets, fruit juices, fruits and vegetables rich in water (watermelon, melon, strawberries, peaches, tomatoes, zucchini and cucumbers), hydration such as yogurt (glass of cucumbers). Another reminder: remember to refresh your skin regularly by sprinkling water with a mister or a wet cloth on the neck and face.
Eat enough
“The heat creates significant stress and the increase in energy expenditure, so we maintain a complete food intake (enough carbohydrates, proteins , lipids) to limit the loss of energy and strength.
Cool down after the session
We wait a little after the session until the body temperature has cooled down and has sweated well before taking a shower (fresh or cold).
Indulge in a nap during the day
We have appropriated this secret of great athletes to optimize their recovery. “We too often forget the positive impact of a nap on the body. It helps to suffer less the effects of the heat that impacts the quality of sleep, especially if the heat wave is prolonged.”
Air-conditioned rooms, the last to practice during the heat wave?
If we have the opportunity to practice in an air-conditioned room, we take advantage of it. The advantage: you can practice at any time without changing your sports habits too much. We listen to our body and adapt the effort, especially in case of fatigue related to lack of sleep. The air-conditioned rooms are also a good alternative for people at risk (chronic diseases, poorly trained or under medical treatment). In this case, ask your doctor for advice.