5 Fitness Myths Busted!

Can muscle turn into fat? Are machines safer than free weights? Does Bigfoot exist? Oxygen put five common, long-held beliefs about exercise to the test and came up with some solid answers to these oft-asked questions.

- Katy Loren

They cling like spandex. Pool like sweat under the Spinning bike. Stick around like that musty odor in the locker room. They’re the long-held beliefs that have been passed down through generations of fitness buff s. “Muscle will turn into fat if you don’t use it!” “Running on a treadmill is the same as running outside!” “If you’re not sweating, you’re not working hard enough!” But as they say, behind every cliché, stereotype and generalization is a nugget of truth, so we decided to put fi ve of the most common myths about exercise to the test and asked a panel of exercise physiologists to set the record straight. Here’s their final verdict on this stubborn fitness folklore. As for Bigfoot, the jury is still out.

FITNESS MYTH 1

Muscle turns into fat if you don’t use it. 

THE VERDICT: False

“This is like saying that if you wear eye patches and you don’t use your eyes, they’ll turn into ears,” says Michele Olson, Ph.D., a principal researcher at the Auburn University Montgomery Kinesiology Laboratory in Alabama. Muscle cells and fat cells are very different, and one cannot magically morph into the other even if it might seem like that’s happening. However, the sentiment behind this statement is correct in its own way: Muscle may not “turn into” fat, but if you’re not active, your body composition can certainly shift, meaning your muscle issue shrinks while your fat cells grow.