An axiom of exercise states that you grow after the workout ends, not during the workout. Many bodybuilders and fitness advocates train intensely, but don't pay enough attention to various recovery processes. Exercise is a stimulus to added muscular size and strength, but to fulfill the stimulus provided by exercise requires a certain amount of time and recuperation following the workouts. Most bodybuilders are aware that they need time to recover between workouts, so they train in a split routine fashion, training different muscles on different days. This allows time for the trained muscles to recuperate from the workout. Indeed, until the 1960s, the most common way to train involved training the whole body in one workout, which was done on three non-consecutive days a week. The great bodybuilders of the past trained in this manner, such as Steve Reeves, 1947 Mr.America, 1950 Mr.Universe, and screen Hercules. Reg Park, who won the Mr.Universe three times in 1951, 1958, and 1965, developed the foundation for his superlative physique by training his whole body three times a week, as did John C.Grimek, the only man to win the Mr.America contest two consecutive years (1940, 1941).
But starting in the late 1950s, bodybuilders began to train in a split routine fashion. This involved training anywhere from four to six times a week. Training in the split fashion allowed a greater volume of exercise to be done before fatigue set it. The notion was that doing a greater volume of exercise, or more sets of exercises, led to a greater degree of muscular size and strength. There was also a psychological factor involved, as it's easier on the mind to train two or three muscle groups in a workout, rather than the entire body. When I first began training at age 12, I trained in a community center gym that was only open three times a week. As such, I had to train my entire body in each workout. I obtained my information about how to train from reading various bodybuilding magazines, and also by sending for bodybuilding courses. This gave me a good head start because those sources of information taught me about proper exercise form and which were the best exercises to pack on muscular mass, which was my primary goal. I did this for the first two years of my training and made tremendous gains. I lost all of my "baby fat," and took on a far more muscular appearance, despite the fact that at 13 years old I wasn't producing enough testosterone in my body yet to support massive muscle gains.
One reason why I made the gains that I did was a combination of my youth and the fact that I allowed sufficient rest and recuperation between training sessions since I trained only three . . .