Key exercise parts: pectoralis major, deltoid and triceps brachii. B. Starting posture: Lie on your back on a flat bench with your feet flat.

Step on the ground. Hold the dumbbell with your palms straight up. C. Action process: make the two straight arms open to both sides and slowly bend the arms.

Dumbbells fall vertically, push up when they reach the lowest point, and exhale when they push up. And then pushed upward to the open position,

Sit down again. D. training points: don't arch your back and hips or hold your breath, which will make your muscles lose control and be dangerous.

2. Dumbbell bird in prone position

Key exercise parts: pectoralis major and deltoid. B. Starting posture: Lie on your back on a flat bench with dumbbells in your palms.

Heart to heart, push up until your arms are straight and supported above your chest. C. Action process: two hand-held dumbbells fall to both sides in parallel,

Elbow slightly flexes, dumbbells fall to both sides of chest, muscles feel fully stretched, and upper arms fall below shoulder water.

Flexible flat cable. Take a deep breath when the dumbbell falls. Exhale when holding the bell and lifting it back to its original position. D. Training points: If dumbbells

When you fall to both sides, if your arms are straight, it is difficult for your chest muscles to feel stretched and contracted.

3. Tilt the dumbbell upward and bench press

Key exercise parts: the upper part of pectoralis major, followed by deltoid toe and triceps brachii. B. Starting position: supine position at the upper oblique angle

On a bench at 35-45 degrees. C. Action process: Hold the dumbbell directly above the shoulder with both arms. Inhale when you put it down above the chest (near the clavicle). When descending to the lowest place, do push-ups and exhale when doing push-ups. D. Training essentials: practice

Cheng focused his main strength on the pectoralis major, keeping it in a state of tension. Triceps brachii as a secondary supplementary strength.

4. Tilted dumbbell bird

Key exercise parts: upper chest and deltoid muscle. B. Starting posture: Lie on your back on an inclined bench and lift dumbbells in the palms of your hands.

Push up relatively until the arm is straight. C. Action process: Two hand-held dumbbells fall to both sides in parallel, with elbows slightly bent, and the dumbbells

Descend until you feel the muscles on both sides of your chest fully stretched. Take a deep breath when the dumbbell falls. Hold the bell and lift it in the same way.

Exhale in place. D. training points: if the dumbbell falls to both sides, if the arm is straight, the chest muscles will be hard to find.

To the feeling of stretching and muscle contraction.