Muscle weighs more than fat: this "fact" has been touted in fitness and weight-loss communities for decades. In reality, this is impossible — five pounds of muscle and five pounds of fat are still five pounds on the scale.
But it is true that muscle is more dense than fat and takes up less space in your body. Beachbody trainer Autumn Calabrese, creator of the 21 Day Fix and 80 Day Obsession, showed the difference between five pounds of fat and five pounds of muscle in an Instagram post.
"Look how sleek, compact and smooth muscle is," she wrote in her caption. "Now look at fat, it's bulky, spread out, misshapen. When we train hard, eat right, get enough rest, we build lean muscle and burn off the fat. This is why it's so important to look at more than JUST the number on the scale."
It's true that the number on the scale doesn't tell the whole story. And not only does muscle take up less space in your body, but it can also help burn more calories at rest compared to fat. Building up muscle can also increase your strength, reduce your risk of injury, and help you build sexy muscle definition.