Short-distance swimming: Many people swim slowly, which burns more calories than fast short-distance swimming. But if you swim fast all the time, your physical strength will be used too quickly. Is it possible to do two slow tours, then two fast tours?
Professional swimmers train by breaking their swimming into four parts, with 15 to 30 seconds of rest in between each part. Swim one round-trip first, then two round-trips, then two round-trips, then two round-trips, and then one round-trip. At the end of each section, you should swim quickly.
Do everything you can while swimming. Do everything you can to keep your heart rate around 80% of your maximum heart rate at all times. In order to meet this standard, smart glasses will record the swimmer's heart rate and show it in front of their eyes in real time.