Key points of alternating arm flexion: alternating arm flexion means that the two arms bend back and forth alternately, and the two arms get uniform motion on one side. Stand with your feet apart and flat on the ground. Hold dumbbells with both hands and hang them at your sides, palms inward. Bend the forearm of the right hand to the chest, so that the dumbbell is raised to shoulder height and the elbow is upward.

Put down your right arm and lift your left arm at the same time, and do the same thing. Don't lean back to help lift the dumbbell. If you need physical help to lift the dumbbell, it proves that the dumbbell is too heavy for you. You should lose weight and exercise first.

2. Hammer swing, left and right 10- 12 times, 4-6 groups.

Pendulum essentials: take a dumbbell in each hand, palms inward. Hands hanging at your sides. Bend your arms and lift the dumbbell to shoulder height. The inside of the forearm should be inward.

3, sit dumbbell outside bending, left and right 10- 12 times, 4-6 groups.

Exercise essentials: Sit on a chair or bench. Hold the dumbbell in your right hand and lower your arm so that your elbow is inside your right thigh. Lift the dumbbell to shoulder height. Keep the main breathing rhythm for 5 to 10 seconds, and then slowly lower it. Repeat the same step with your other hand.

Extended data:

Precautions:

1. From the first group, every movement should be slow and long. I won't write much about biceps brachii exercise here. I believe all fitness friends know the exercise of biceps brachii.

2. Starting from the second group, officially start to exercise biceps brachii, requiring each group to complete at least 6 to 8 groups under the load of 90% strength.

3. Using the above methods to exercise biceps brachii requires good training effect, and biceps brachii needs at least two exercises. For example, bend with dumbbells first, then with barbells, and finally with ropes.