Fitness is equivalent to strenuous exercise, and it is dangerous to jump into cold water immediately after that. Because just after exercise, the blood is in the limbs of the human body, and it takes some time to return to the heart. The body radiates heat and sweats through pores, and the pores are open at this time. Heart rate is fast, blood pressure rises, body temperature rises, and you can't go into the water immediately, otherwise it will easily cause cramps and colds.
If you need to swim after fitness, you should take a short rest and dry your sweat, and then go swimming after your body temperature, heart rate and blood pressure return to normal. In addition, the intensity of swimming should not be too great, and physical strength should be guaranteed.
Extended data
Precautions for swimming:
1, avoid swimming in the sun for a long time.
Prolonged exposure can lead to sunburn or acute dermatitis, also known as sunburn. In order to prevent sunburn, it is best to use an umbrella to shade the sun after landing, or rest in a cool place, or use a bath towel to protect the skin, or apply sunscreen to exposed parts of the body.
2. Avoid swimming without warm-up activities.
The water temperature is usually lower than the body temperature. Therefore, warm-up activities must be done before entering the water, otherwise it will easily lead to physical discomfort.
3. Avoid eating immediately after swimming.
It is advisable to rest for a while before eating after swimming, otherwise it will suddenly increase the burden on the gastrointestinal tract, which will easily lead to gastrointestinal diseases after a long time.
Baidu encyclopedia-swimming