Define Lean Muscle

Muscle mass is the main goal of weightlifting and bodybuilding. Muscles not only provide strength and power, but can be a visible manifestation of health and an essential part of a well-toned physique when not obscured by a layer of fat. Thus, the challenge of gaining lean muscle mass, without fat, is of primary importance to many athletes.

A buff man is flipping a tire. (Image: Ibrakovic/iStock/Getty Images)

Muscle

Muscle is a band or bundle of tissue consisting of fibers that have the ability to contract. In addition to water, muscles mostly consist of protein, particularly actin and myosin, the interaction of which converts chemical energy into mechanical energy. Muscle gives the body movement. Muscles are divided into groups, each of which performs a specific function in the body. Skeletal muscles, which are attached to bones, are generally the most visible when not obscured by a layer of fat.

Lean Muscle Mass

Lean muscle is a concept related to lean body mass, which is the content of the body minus fat. Lean body mass is used to calculate basal metabolic rate. Lean muscle is less of a scientific term and more a term of art that refers to muscle that is independent of, and not obscured by, fat. In the context of bodybuilding, lean muscle mass is that which is gained without a corresponding addition of fat or that which remains after fat is shed. It can also be thought of as the amount of muscle on the body independent of fat, bone and other parts.

Gaining Lean Muscle Mass

When bodybuilders speak of gaining lean muscle mass, they seek to increase the amount of muscle on their body without simultaneously gaining fat. This can be challenging because the body tends to either be adding mass or breaking it down, depending on whether you consume more calories than you burn. The body stores excess calories not as muscle, but as fat. Still, according to personal trainer Jeff Grant, it is possible to gain muscle without fat by increasing your intake of carbohydrates at breakfast and after workouts, and lifting heavier weights.

Losing Weight Without Losing Muscle

One of the greatest challenges to achieving a well-defined muscle tone is entering a catabolic state where your body is breaking down primarily fat, but not muscle. According to personal trainer Shawn LeBrun, it is a myth that doing targeted exercises will remove fat from specific areas. Men's health site AskMen.com recommends a specific regimen consisting of three parts. To lose fat but not muscle, you should decrease your total caloric intake while maintaining an intake of at least 1 g of protein per pound of bodyweight. About 15 percent of your total calories should come from fat. At the same time, perform daily 20- to 30-minute, medium-paced cardiovascular exercise and limit the number of sets and reps in your strength training, but not the weight.