Early dumbbells were usually made of stone or metal under ten pounds. By the 13th century, dumbbells had evolved into iron balls installed at both ends of short handles. Today, the handle in the middle of dumbbells can be a horizontal bar, and the load-bearing parts on both sides are usually disc-shaped metal blocks. There are dumbbells with different weights in the gym, which can be taken by the exercisers as needed. Some dumbbells, like barbells, can increase or decrease metal blocks to adjust the load.
Long-term practice of dumbbells can modify muscle lines and increase muscle endurance. Regular practice of weight-bearing dumbbells can make muscles strong, strengthen muscle fibers and increase muscle strength.
Extended data:
1, lateral bending
Hold the dumbbell with both hands or one hand (the fist eye is forward), the upper arm is close to the body, bend the bell up to the shoulder, and slowly put it down to recover. Mainly develop forearm extensor muscles, and develop upper arm anterior muscles at the same time.
2. Hold your wrist and bend it.
Hold the barbell with both hands (palm down), the grip distance is shoulder width, and the upper arm is close to the body side. Bend the barbell upward, lift it to the limit, and then slowly lower it to recover. During exercise, the forearm muscles are always in a state of tension and exertion. Mainly exercise the extensor muscles of forearm and the lateral muscles of upper arm.
3. Prevent wrist bending
Sit at the end of the stool, hold the barbell with the palms of both hands up, the grip distance is shoulder width, the forearm is attached to the enlarged leg, and the wrist is relaxed. Bend the barbell up hard until it can't bend any more. Then relax and recover. This action can put the forearm on a flat stool or hold a dumbbell in one hand. Mainly exercise forearm flexors.
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