Long-term practice dumbbells, can modify muscle lines, increase muscle endurance, often do weight weight dumbbell exercises, can make muscles strong, strong muscle fibers, increase muscle strength. Can exercise the upper limb muscles and waist, abdominal muscles. If you do sit-ups in the back of the neck with both hands holding dumbbells, you can increase the load of abdominal exercises; Hand holding dumbbell to do lateral flexion or rotation movement, can exercise abdominal internal and external oblique muscle; The straight arm forward lift and side horizontal lift with dumbbell in hand can exercise the shoulder and chest muscles. Can exercise lower limb muscles. Such as holding dumbbells squat up with one foot, squat jump with both feet, etc.