“Lean muscle” is a phrase that fitness marketing often uses to target women. It’s placed in comparison to “bulky” muscles, something that women are not supposed to ever gain. To be “lean” is feminine and attractive, while to be “bulky” is masculine. It’s a way of pitting thinness against strength, while still appealing to women’s desire to workout and gain muscle definition.
However, in the sense that many people in the fitness world use it, there’s no such thing as “lean muscle.” It is a buzz word.
You cannot change your muscle tone. You cannot lengthen your muscles. These things are largely determined by your genetics and body type. You cangain muscle mass and lose muscle mass, but you cannot control the shape that your muscle takes on. You can only gain or lose fat in order to make the muscle more visible as you gain and lose muscle mass. In the end: You control size and visibility, not shape or tone.
Lean muscle exists in the sense that all muscle is lean. It is lean tissue. This is in comparison to body fat, which is not categorized as lean. Therefore, if you want to gain “lean” muscles, what you’re actually trying to do is have a body that contains a relatively low fat percentage while increasing your muscle mass. Larger muscles + low body fat = the appearance of being lean.
“But how is that different from bulking?” you ask. Honestly, it isn’t significantly different. These two things are separated only by genetic predisposition and extremity. Bulking is simply taking this process even farther - Someone who wishes to become bulky will seek to gain even more muscle mass and lose even more fat. “Bulky” is just a few degrees more extreme than “lean.”
According to the American Council on Exercise, it’s largely a myth that weight-lifting doesn’t cause women to bulk up. It is true, however, that one’s tendency to develop bulky or lean muscles varies widely from one person to the next. While the male hormone, testosterone, does contribute to muscle growth, body type is just as important a factor in how your body responds to strength training. If you have a muscular mesomorph body type, you’ll quickly take on more muscle mass. If you’re a more voluptuous endomorph, you’ll typically lose weight before you see notable growth in muscle. Slim ectomorphs are unlikely to ever develop bulky muscles, even as they become stronger.
It is entirely possible, then, that the same mass of muscle will appear “bulky” on one person and yet will appear “lean” on another. This distinction depends on the rest of that person’s body, their overall shape and their genetic tendency to hold onto muscle mass and fat.
This is important to recognize because lean muscle is presented as the socially acceptable version of bulking for women. It’s a weight loss concept that’s framed in terms of feminine strength. Adding “lean” as a descriptor is what allows fitness marketing schemes to continue promoting weight loss as the primary goal for women. In truth, the process of building such muscle is actually accomplishing the same physiological reactions as bulking in the more (traditionally) masculine forms of bodybuilding.
If any trainer tries to tell you that certain exercises or regimes will build lean muscle - Back away. They either 1. don’t know what they’re talking about and actually believe that “lean” muscle exists, 2. They think that spot reduction is a valid concept in fitness, or 3. They are intentionally throwing around buzz words in order to get your business without actually explaining their plans properly. (Also watch out for phrases like “toning,” “fat burning zone” and “cleanse.”) None of these options should be acceptable when your health and safety is on the line.
For further reading, check out these resources:
Wisegeek: What is Lean Body Mass?
