Training even in a heatwave? Here is how to do it right

The summer heatwaves in Israel do not have to stop your training routine, but they definitely require us to train differently. Physical activity is important for health, fitness, mood, and maintaining a routine, but when temperatures climb and humidity is high, the body deals with additional stress, one that you don't always feel at the beginning of the workout, but which can become dangerous if you don't pay attention to the warning signs.

During physical activity, the body naturally produces heat. To cool itself, it increases sweating and raises blood flow to the skin. This is how the body tries to move heat out and maintain a normal temperature. However, on particularly hot and humid days, this cooling mechanism works less well: sweat evaporates more slowly, the body loses more fluids and salts, the heart rate rises, and the load on the heart increases. In such a state, even a workout that usually feels easy and routine like a short run, cycling, a ball game, or a strength workout, can become challenging.

The main danger is that the body does not always signal in time. Sometimes you start the workout feeling good, but as the effort continues, especially under direct sun or in stagnant and humid air, there is an increase in heat stress. In such situations, dehydration, heat exhaustion, muscle cramps, and in more severe cases, heatstroke — a life-threatening medical condition that requires immediate treatment — can develop.

Which workouts are more dangerous?

The highest risk exists in prolonged or intense activity performed outside, especially during the hot hours of the day. Long runs, interval training, prolonged cycling, ball games, CrossFit workouts outside, or any activity that includes high effort over time, increase the risk of body overheating. The longer the effort and the more the body is exposed to the sun, the harder it is for it to regulate temperature.

Even swimming, which seems to many as a completely safe activity on hot days, is not free of risks. The feeling of coolness of the water can be misleading, because the body is still exerting itself, sweating, and losing fluids. Therefore, it is important to drink before entering the water and also after exiting it, especially during a long swimming workout or in the open sea. On the other hand, more moderate activity like walking in the cool hours, yoga, Pilates, or strength training in an air-conditioned space will usually be safer, as long as you adjust the intensity, maintain hydration, and listen to your body.

How to train correctly on heatwave days:

1. Train during the cooler hours: early in the morning or in the evening hours. Avoid as much as possible training during the noon hours, when the heat stress is particularly high.

2. Drink water before, during, and after the workout: do not wait for the feeling of thirst, because it does not always reflect the fluid status in the body in real time.

3. Reduce intensity and duration of the workout on particularly hot days: this is not the time to break personal records. Sometimes a short and moderate workout is much better than a long one that burdens the body.

4. Choose correctly: wear light, ventilated, and bright clothes, wear a hat, and prefer a shaded path or an air-conditioned space. Choosing the right place for the workout can also significantly reduce the risk.

5. Adapt: if you have returned to training after a break, increase loads gradually. The body needs time to adapt to the heat, especially at the beginning of the summer or after a period without activity.

When must you stop?

During a workout in the heat, it is important to pay attention to unusual signs. If dizziness, headache, nausea, uncharacteristic weakness, muscle cramps, confusion, chills, or an especially high heart rate appear, you must stop the activity immediately. In such cases, it is important to move to a shaded or air-conditioned place, drink water, cool the body, and avoid further effort. If significant confusion, loss of consciousness, very high body temperature, or deterioration in general condition appear, you must call for medical help immediately. It is possible that this is heatstroke, and this is a medical emergency.

Physical activity is an important part of a healthy lifestyle even in the summer, but on days of heat stress, it is important to remember: the goal is not just to finish the workout, but to return from it healthy. Adjusting the type of activity, the time, the duration of the workout, and the intensity to the weather conditions will allow you to continue training safely, even in the hottest periods of the year.

Dr. Zhanna Olkhov is a specialist in family medicine and specializes in sports medicine, Maccabi Healthcare Services.