Dumbbells are the most well-known and widely spread fitness equipment, whether in commercial gyms or family training equipment. Dumbbell double bending should be the fitness enlightenment for many people, but most people's understanding of dumbbells is limited to double bending. Worse, at least 80% people may have done the wrong action of dumbbell double bending.

There are still some people who create some wrong or inefficient actions by feeling, and the typical action is standing and pushing. In addition to destroying your fragile shoulder joint, this action is useless for improving strength and maintaining health. Because the resistance of dumbbells comes from gravity, try to ensure that the trajectory of dumbbells is vertical to the ground during training.

The ancient Greeks first invented the prototype of dumbbell, which they called "haltere". This is a crescent stone with a handle, which was originally used as an auxiliary training tool for weightlifting and long jump. Dumbbells originated in Tudor England, when Hercules liked to train upper limb muscles with church bells held by churches. In training, the hand-cranked clock makes a lot of noise, so they take down the clapper in the clock to eliminate the noise, so the clock becomes a "dumbbell", and they call this equipment a dumbbell.

Over the years, people have developed many dumbbell training movements, which can be used to train any part of the body. However, under the impact of various beautiful ropes and fixing instruments, dumbbells become too rustic and simple, and many people neglect to exercise with dumbbells. Dumbbells are left out in the corner of the gym and play a role in pressing the bottom of the bed at home.