Under normal circumstances, it is best to go swimming from 3 pm to 6 pm, and your body function is at its best. 1 hour is enough for one person to swim. Breaststroke is best not to practice swimming more than 200 meters, which is easy to cause lumbar disc herniation. But if it's not waves, just amateur breaststroke should not be a problem. If you want to swim more than 200 long distances, you can only swim freestyle, and other long-distance swimming will have adverse effects on your health.