The benefit for doing leg excercises, appears from research not to be from increasing long term natural levels of testosterone and GH. I believe however the large burst of testosterone and other hormones during leg excercises, are the major reasons why squats and deadlifts are very important for overall muscle building. It’s the same reason why a bench press is more effective mass builder than a chest flye workout. Why? because the compound bench press is going to release more testosterone and GH in a workout than a chest flye.
The large burst of anabolic hormones resulting from squats and deadlifts, allows most of your muscles to benefit from this release simultaneously. Squats and deadlifts work many muscles simultaneously in the body and will allow most of your body to get some stimulation from the release of the hormones during the workout. The testosterone and GH released, is very crucial for being a catalyst for your muscle growth. It won’t be released as much in the smaller compound excercises, such as bench press. Therefore doing smaller compound excercises, would not be able to makeup for the benefit of having leg workouts in your routine.
