1 paddling
Do an extra 20 minutes of paddling every day, and it will work if you feel your arms are sore. You must persist for a period of time, and the effect will not last for a short time.
2 tension spring
Find some of the lightest springs. Never buy it for boys. You can straighten them easily unless you want to build some muscles. You can pull for a few minutes at any time and place every day, with little exercise and more conducive to persistence.
3 arm massage
Fingers together straight, joints slightly bent. Find the acupoints, massage in circles, and apply with your palm.
Lie on your feet and press and knead each acupoint, and keep pressing and kneading each acupoint for one minute. Elbows should bend naturally, not too stiff.
Ten minutes a day is enough.