To slow down aging, the elderly must strengthen their brains

　　Beat and rub alternately in a sitting position, put the palm of your left hand on your left thigh, and rub it back and forth. Make a fist with your right hand, place it on your right thigh, and beat it up and down. Move like this one pinch at a time, and then change hands after you become proficient. That is, the left hand is changed to a fist. Place it on your thigh and beat it up and down. Then stretch your right hand and rub it back and forth on your right thigh. With such accurate alternation, 30 alternations per minute is considered excellent, 20 times is good, and less than 20 times is poor.
　　
　　With the thumb and little finger alternately make a fist with your left hand and extend your thumb, make a fist with your right hand and extend your little finger, and then switch hands. That is, retract the thumb of the left hand. And extend the little finger, the right hand retracts the little finger, and extends the thumb, and so on. A score of 15 times per minute is considered excellent, 10 times is considered good, and less than 10 times is considered poor.
　　
　　Fist and palm alternately make a fist with your left hand and extend your palm with your right hand. The fingertips point to the hypothenar of the left hand (the little finger side of the left fist), then make a fist with the right hand, extend the palm of the left hand, and point the fingertips to the hypothenar of the right hand (the little finger side of the right fist). By swapping left and right in this way, 20 times of alternation within 15 seconds is considered excellent, 15 times is considered good, and less than 15 times is considered poor. If your results are not satisfactory at the beginning, you can practice more in the long run.