1. Old people had better choose wooden fitness balls. You don't have to wear gloves, and it won't be cold in winter.

2. Fitness ball makes fingers, palms and wrists flex and stretch flexibly through the movement of fingers and palms, promotes the movement of upper limb muscles such as fingers, wrists and elbows, and prevents and corrects symptoms such as numbness, trembling and decreased grip strength of upper limbs caused by degenerative diseases of the elderly.

3. Fitness balls are made of various materials, such as jade, marble, steel and copper, and some only use two walnuts as balls.