Scientific use of dumbbells, really can receive a good exercise results. Some materials said that when Schwarzenegger a bodybuilding muscles, mainly through the dumbbell exercise derived. However, after a lot of people exercise with dumbbells, they have neither increased their strength nor become body-building. They often feel disheartened and dumbbells have been shelved. They have even become substitutes for hammers. In fact, dumbbells fitness knowledgeable. If not implemented, the effect of exercise is often not satisfactory.