An ongoing obsession of bodybuilders and strength athletes is boosting growth hormone (GH) levels. This preoccupation extends back to the 1980s when, inspired by the infamous “Life Extension” duo Durk Pearson and Sandy Shaw, bodybuilders gulped down ungodly amounts of the GH-spiking amino acid l-arginine (and, in some instances, l-ornithine) in the hope of experiencing steroid-like muscle growth.
Squatting for Upper Body Growth?
Weight training folklore has long held that performing heavy lower body exercises such as squats results in extra muscle growth, not just in your legs but in your upper body as well. According to this theory, by regularly performing heavy squats your chest, shoulder, latissimus and arm exercises will produce more muscle growth than they otherwise would. The reason for this extra muscle growth, so the story goes, is that squats cause your body to pump out greater amounts of GH.
A lot of folks in the Iron Game regard the squats-boost-H-boosts-upper-body-muscle-growth theory as a sacred tenet, and can readily regale you with tales of how their best whole-body muscle gains were made whilst regularly performing gut-busting squat sessions.
Others think the squat-upper body growth theory is a load of bollocks and maintain they’ve never noticed any difference in upper body growth as a result of regular squatting.
So who’s right?
Gone in Sixty Seconds
The fact that short rest periods (60s or less) produce greater GH spikes than longer rest periods between sets is not in dispute – it has been shown time and time again in controlled studies. Science has also clearly demonstrated that performing heavy leg workouts results in a far greater GH spike than performing workouts comprised solely of exercises for small muscle groups such as the upper arm muscles.
The real question is, do the brief growth hormone spikes that occur in conjunction with weight training workouts actually help to increase muscle growth or strength?
In 2001, a study was published in which 16 young untrained males were assigned to an arm-only training group, or a leg plus arm training group [1]. The study lasted nine weeks, and hormonal responses were tested during the first and last training sessions.
