Of Greek Heroes, Wiggling Worms, Mighty Mice, and Old Body Builders

HERACLES (Hercules according to the Romans) was probably the earliest and greatest body builder of all times and, without doubt, the greatest hero of Greek mythology. His conception, the result of a brief affair between the supreme deity Zeus and a mortal woman, made Zeus's wife Hera furious. She surreptitiously inserted two deadly snakes into Heracle's crib. According to legend, that evening, a nurse found the delighted baby giggling and joyfully playing with a strangled serpent in each hand. Are stronger people already stronger at birth, as the Heracles legend seems to suggest? Is the destiny of our muscles already encoded in our genes (1)? Perhaps more importantly, what is the role of genetics as opposed to behavioral and environmental factors in the maintenance of muscle mass and strength with aging?