It's a little hard to practice dumbbells with one hand weighing 20 kg, but I can persist in a group of 20 times a day. In the five groups, biceps brachii was painful after getting up the next morning, and it was obviously painful to straighten their arms. No injuries. Occasionally, physical exercise can cause muscle stretching pain. You can do some light activities and aerobic exercise instead of doing the same exercise the next day.

Fitness exercises don't need to be done every day, but they can be done every other day, but they should be mixed with aerobic activities, stretching and so on.

In addition, if you want to exercise, a group of 20 times is too much, usually between 10 and 15 times, which is mainly related to endurance.