The dumbbell is a simple equipment/tool used to build muscle strength. Its main material is cast iron, and some dumbbells are covered with a layer of rubber. Dumbbells are mainly used for plyometric training and muscle compound movement training. If an exerciser uses dumbbells in a scientific approach, he/she can indeed receive pleasing exercise fruits.
In terms of the material and manufacturing process of dumbbells, dumbbells can be classified into seven types, namely, the wood steel dumbbell, water dumbbell, electroplated dumbbell, plastic-dipped dumbbell, rubber-coated dumbbell, sponge dumbbell and baking varnish dumbbell.