Which Is Best for Hormones: The Bar or the Machine?

Testosterone and growth hormone are associated with strength and muscle gains. But what is the best training method for eliciting an acute hormone response? A study published in the Journal of the National Strength and Conditioning Association (2104; 28 [4], 1032–40) contributes to this debate.

The primary focus of the study was to determine which type of lower-body resistance exercise protocol—free weights or machine weights—would elicit the greater postworkout hormone response. The intervention included 10 resistance-trained men who completed 6 sets of 10 repetitions of barbell squats and seated leg press. A week separated the protocols. Blood samples were taken before and immediately after each session and again 15 and 30 minutes postexercise.

From the blood samples, researchers learned that both training types resulted in higher levels of testosterone, growth hormone and cortisol at each time interval. However, in the battle of free weights versus machines, free weights came out on top in every measure.