1. Use skirting board: Water toys such as skirting board, paddling board, flippers and lifebuoy not only help to burn more calories, but also exercise the muscles of limbs.

2. Fast short-distance swimming: you can slow down first and then fast, then slow down first and then fast.

3. Time-phased practice: Like professional swimmer training, swimming is divided into four segments, with breaks between segments 15-30 seconds. The specific arrangement is to swim 1 round trip, then swim 2 round trips, then swim 2 round trips, and finally swim 1 round trip, and each section ends with a quick swim.

4. Go all out when swimming: keep the heart rate at about 80% of the maximum heart rate. In order to ensure this standard, every time you swim, you should count how many times your pulse jumps in 6 seconds, and add a "0" after it, which is 1 minute heart rate.