It is a normal physiological reaction that the body's heart rate increases after fitness, but if the heart rate is too fast, it may have adverse effects on the body. It is recommended that you pay attention to the following points during exercise:

1. Gradually increase the intensity and time of exercise, and don't start with high-intensity exercise.

2. Maintain proper diet and water intake, and supplement the energy and water needed by the body.

3. If the heart rate is too fast, you can appropriately reduce the intensity of exercise or stop exercising, so that the heart rate will gradually return to normal.

4. If the heart rate continues to be too fast or irregular, please seek medical advice in time.