Fitness novices need to buy dumbbells according to their actual situation. It is generally recommended to buy detachable dumbbells because they are convenient, practical and easy to keep. The weight of the free combination was 2KG, 4KG, 6KG, 8KG, 10KG, 12KG, 14KG, 18KG, 20KG, respectively. If you are practicing your arms or shoulders, you will need less weight than your chest muscles. So it takes different weights to exercise different muscles. Weight can be increased appropriately with the passage of exercise time. After a novice buys a dumbbell, it is recommended not to rush to exercise with heavy weights, but to train with small weights. Find the feeling of the target muscle group first, and then gradually increase the weight to increase the training intensity. Expand the content. Joint activities, warm-up and muscle stretching should be done well before dumbbell fitness (the time is about 10 minute), and small-load exercise should be done before each exercise to make the target muscles enter the fitness state. After exercise, do muscle stretching and finishing activities (don't just sit down and relax), and don't eat, bathe or supplement food for half an hour. Breathing rules: If you are not used to breathing at first, you should learn it eventually. It is recommended to exhale when exerting strength and inhale when recovering. Never hold your breath! Drinking water law: You also need to drink water during the fitness process, otherwise it is easy to lack water. Prepare a cup of warm water before exercise, and drink a small amount of water (50ML) after each exercise.