Don Dengel, PhD, professor of kinesiology and director of the Laboratory of Integrative Human Physiology, is the author of a recent blog post entitled, “AYSMMETRY IN THROWING AND NON-THROWING ARMS OF NFL QUARTERBACKS.” This blog examines the effect of constant throwing exercise on the lean skeletal muscle mass, fat mass and bone mineral density determined using dual X-ray absorptiometry (DXA) in the throwing and non-throwing arms of 21 quarterbacks.