For those who swim in winter, the cold sea water is undoubtedly the biggest threat, and their metabolism and blood circulation will be faster and faster. For a young man, if he can persist in 1 hour or so, he will usher in a fatigue period. At this time, don't insist. When you find that your physical strength reaches the limit, you must go ashore, otherwise it will be too late to go ashore when you are exhausted.
For the elderly, I personally suggest that the best time for winter swimming is 20 minutes. It is natural for the elderly to exercise, which is why we see so many elderly people doing morning exercises in the park every morning. But for the elderly, their physical function is actually much worse than that of young people. Some things can't be forced. Twenty minutes can not only achieve the purpose of exercise, but also improve your level.
For professional athletes, it takes more than 2 hours to swim in winter. As we all know, the vital capacity of swimmers is much higher than that of ordinary people, so they have inherent advantages in winter swimming. In this case, occasional training 1 hour can't solve the problem at all. If you want to truly become a world champion, you need to work harder than ordinary people. Without hard work, you won't succeed, so 2 hours is a minimum standard.
For people who eat melons, try not to swim in winter. After all, many people have average physique, which is different from swimming pools. Many people will react when they enter cold water, and there will be sudden situations such as cramps. In this case, your chances of being rescued will drop a lot, so be careful in winter swimming. Be sure to consider your own safety. Don't be a hero for a while. Not cost-effective. Then you will understand the pain of killing one thousand and losing one thousand two hundred.