Can puberty be delayed by not doing exercise?

Puberty: Exercise or no exercise should not affect the onset of puberty. There is a pretty wide range of when you can start puberty. Boys tend to start puberty later than girls. Feel free to post with more questions if that did not clear up your concerns.

Obesity may affect.: Evidence suggests obesity may increase estrogen production, which hastens puberty in girls but may delay (or have no effect on) puberty in boys. Therefore it is not really lack of exercise that alters puberty, but body mass index. Therefore, in girls, lack of exercise may cause early puberty. In boys there is not enough evidence to determine whether exercise affects pubertal onset, or not.