is it true cardio exercises increases your growth hormone and decreases testosterone?

Answer 1

if cardio is performed at or near the Vo2Max it will increase GH secretion. look at any elite sprinter male or female, the males are all in single digit body fat and the women in the low-mid teens. growth hormone is the most powerful fat burning compound that the body makes and as the most anti-catabolic compound. it burns fat and preserves lean body mass.

and yes too much cardio can decrease testosterone production. distance runners have low test production and low levels of resting testosterone values.