If you want to exercise arm muscle strength, the key is to exercise biceps brachii and triceps brachii, and then exercise these two parts:

First, biceps brachii

1. Alternate bending

Mainly practice biceps brachii and separate biceps brachii.

Action: Sit (or stand), hold dumbbells in both hands and hang them to your sides, palms facing each other, elbows leaning against your sides. With the elbow joint as the fulcrum, bend upward, at the same time, the palm is up, the forearm rotates outward, lift to the highest point to tighten the biceps brachii, pause, and then control the reduction. Do it in turn.

Step 2: Alternate bending

Mainly practice biceps brachii muscle peak.

Action: Stand, bend forward naturally, hang the dumbbell in front of you with one hand, and rest your upper arm on the same knee or leg. The other hand bends the arm and puts it on the same knee or leg to stabilize the body. The arm holding the dumbbell bends upward to the highest point, so that the biceps brachii contracts to the limit, stops for a while, and then slowly recovers.

3. Lateral bending

Mainly practice the brachialis and forearm muscles.

Action: Sit (or stand), hang dumbbells on both sides of your body with palms facing each other, with your upper arms close to your sides and your elbow joint as the fulcrum, bend upward to the highest point, pause for a moment, and then slowly recover. Tip: Both arms can be carried out simultaneously or alternately.

Second, triceps brachii

1. Flexion and extension of the posterior cervical arm

Mainly practice triceps brachii.

Action: Sit (or stand), with one end of the dumbbell on the back of the neck, palm forward, upper arm fixed, elbow as the fulcrum, arm bent and arm extended. Tip: Both arms can be carried out simultaneously or alternately.

Bend over and stretch your arms.

Mainly practice the upper part of triceps brachii.

Action: Bend over, lunge forward and backward with your feet, hold your front legs and knees with one hand to stabilize your body, and raise dumbbells with your upper arms close to your body. The triceps brachii is stressed and stretched forward and backward until the forearm is parallel to the ground, so that the triceps brachii contracts to the limit, pauses for a while, and then slowly recovers.

Moreover, protein should be supplemented after exercise to fully recover the injured muscle fibers.