But in fact, the weight loss we are talking about is actually a process of reducing fat. Fat consumption requires long-term anaerobic exercise, which means you have to keep exercising for 30 minutes to really get results. In other words, the most important thing is to keep exercising. In fact, most people insist on running for an hour or so without any problems. Even if you can't run, you can achieve the effect of reducing fat by walking fast, as long as you continue to exercise to a certain extent.
However, swimming requires higher skills. Most so-called swimmers need a rest after swimming for more than ten minutes. They often go swimming in the swimming pool for three or four hours, but the actual exercise time is only about one hour, which is still intermittent (if you swim slowly with breaststroke, many people can persist for a long time, but the amount of exercise in this way is far less than running).
So from a practical point of view, if you want to lose weight, running is the most effective, but stick to it.
In addition, people who are overweight (at least more than 30% of their normal weight) are not advised to run a lot at the beginning of losing weight, which will cause a serious burden on their knees. Swimming is a good way to supplement them.