There is nothing related to dumbbells that affects height development. Lz, don't worry. At your age, it's best to focus on aerobic exercise, such as jogging 2-3 times a week for 5000 meters, so it's good for you to practice more pull-ups at ordinary times.

Dumbbell bending arm should pay attention to that when relaxing, the arm should not droop completely, and should keep a certain angle with the upper arm. This is the so-called constant tension. When you slowly lift to the top, you should deliberately contract your biceps. It is called peak contraction. You should pay attention to these ideological things when you do anything.

Push-ups are divided into narrow distance and wide distance, mainly involving pectoralis major, triceps brachii and deltoid muscle.

Children are 13, so considerate and so good. On behalf of Anoos Wochenger, I wish you further and further on the road of bodybuilding!