does crunches affect height ??!

Height is mostly genetic, so exercise shouldn’t slow growth. I wouldn’t be too concerned.

 

I agree, the height is 95% genetic, and crunches are great exercise, just watch out to do it the right way so you don`t damage your spine. I don`t know if crunches increase testosterone, but I know that squats and deadlifts are probably the best exercises to increase your natural testosterone, especially if you are beginner.

 

Crunches help to get a better core for your body. But it is important to make different abs-exercises to get defined and helpful abs - only crunches are not enough. For example flutter kicks, leg raises, crunch kicks, ellbow plank etc.
Darebee.com has a lot of different abs-workouts.

 

I am 5'5 and I feel insecure