BRIDGING THE GAP
RESEARCH and PRACTICALITY
Toning Your Muscles
One of the most common goals for people training in the gym is muscle toning. In fact, more so than training for performance or size most people want to get more toned without getting any bigger – particularly women.
People often ask me how they can get a solid appearance without the added size. While the “toned” appearance has much to do with diet and aerobic exercise, there are some measures you can take in the weight room in order to emphasize your goals.
Every muscle contraction and weight lifting exercise is divided into two phases: the eccentric (lengthening) contraction and the concentric (shortening) contraction. In an eccentric contraction the torque produced by the weight (external resistance) is greater than the torque produced by the muscle (and the muscle lengthens). A concentric contraction is simply the opposite; the torque produced by the muscle is greater than the torque produced by the weight (and the muscle shortens).
A good general rule of thumb is the concentric phase includes shortening of the muscle, while the eccentric phase includes lengthening of the muscle performing the exercise. For example in a triceps pushdown, the downward movement is the concentric contraction and the return to starting position (upward movement) is the eccentric phase because your triceps are shortening and lengthening, respectively.
In order to emphasize toning, you must concentrate on performing exercises with limited eccentric phases (large range of motions) and focus on lifting maximal weight in the concentric phase and limit any focus in the eccentric phase. For example, choose bench press over dumbbell fly for your pectoral exercise since bench press has a limited eccentric phase when compared to the dumbbell fly. This will provide strength improvements without the hypertrophy.
Hypertrophy is an increase in muscle size due to training induced damage to the muscle. The eccentric phase induces the most damage and therefore causes the most hypertrophy. If you can strengthen your muscles without adding the size, with time you will begin the feel and appear more toned.
Look for future posts on common exercises for specific muscles groups in order to put your toning knowledge to practice.
Written by Aaron Losey, B.A. Kinesiology, Occidental College, Los Angeles, CA