The first question you have to ask yourself is: What is the purpose of building muscle? There are three types of muscle fibers: type 1 or slow-twitch fibers, type 2 or fast-twitch fibers and type 3 or intermediate fibers. The slow-twitch fibers provide endurance and aerobic capacity and are best built with high repetition, low-resistance forms of exercise. The fast-twitch muscle fibers provide for more explosive, powerful activities and develop with lower repetition, higher resistance training. Research suggests that the intermediate muscle fibers have the capacity to become either slow-twitch or fast-twitch fibers depending on how they are stimulated.

If your goal is to improve general fitness and tone your muscles, then the classic program would include three sets of 10 reps. Once the weight becomes relatively easy to handle then the exercise should be progressed in its degree of difficulty or the weight should be increased slightly, resulting in lower repetitions of each exercise. This should be done under the supervision of a personal trainer.

ANSWERED BY:
Erin Boynton, MD, FRCSC, an orthopedic surgeon specializing in sports medicine and shoulder surgery. She was the first woman to work as an orthopedic surgeon in the NHL, MLB and CFL.