1, flat dumbbell bird. The target muscle group is the middle bundle of pectoralis major.

2. Tilted dumbbell bird. The target muscle group is the upper bundle of pectoralis major.

3. Dumbbell bird leaning down. The target muscle group is the lower bundle of pectoralis major.

The above three movements have a good effect on increasing the thickness of pectoralis major muscle and depicting the suture line of chest.

4, bending over the dumbbell bird is also often said to fly back. This action can easily be misunderstood as back training. In fact, the correct way is to take the shoulder as the axis and the target muscle group is the deltoid posterior bundle.