Pump it Up to Build Muscle

Ivanhoe Newswire
Friday, December 1, 2006; 12:00 AM

(Ivanhoe Newswire) -- Women who want to build muscle during weight training need to include a heavy loading cycle in their workouts.

That's the key finding from new research led by investigators from the University of Connecticut who explored the role of growth hormone in building muscle and bone.

"We found that growth hormone was responsive to moderate and heavy exercise regimens having 3-12 repetitions with varying weight loading," reports the lead author of the study, William J. Kraemer, Ph.D. "Women need to have heavy loading cycle or workout in their resistance training routines, as it helps to build muscle and bone."

The researchers explain women rely more heavily on growth hormone to build muscle than men, who mainly build muscle via the male hormone testosterone. But not all growth hormone is created equally. Produced in the pituitary gland, growth hormone is composed of 191 different amino acids that can break apart and rearrange themselves into smaller and larger pieces.

This study showed the presence of growth hormone varied with the workout program and also varied according to the test the researchers used to detect it. Specifically, larger-sized growth hormone types were more prevalent when women engaged in heavy resistance training.

The study was carried out among women who participated in either upper body training or total body training. The two groups were further divided into those engaging in heavier weight training with fewer repetitions and those engaging in lighter weight training with more repetitions.

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SOURCE: American Journal of Physiology-Endocrinology and Metabolism, 2006;291:E1177E1187