The weight selection of dumbbells should be based on personal fitness goals and use requirements. Beginners can choose 3-5 kg dumbbells, and those who have no fitness foundation are advised to choose 5 kg dumbbells. Those who have a fitness foundation can determine the weight of dumbbells according to 40% of the maximum negative weight. There are also differences in dumbbell weight between men and women, and there are also differences in different muscle groups and movements.