2 Myth: Fat can turn into muscle and muscle can turn into fat.
Fact: You can burn fat and build muscle (sometimes even with the same routine!), just like you can gain fat and lose muscle. But make no mistake, fat and muscle are two different types of tissue, and you can’t turn one into the other. “The best analogy I can use is, you cannot turn an orange into an apple,” Brad Schoenfeld, an assistant professor of exercise science at the City University of New York’s Lehman College, told LiveScience.
3 Myth: You start losing muscle mass after just a week of inactivity.
Fact: It may be true that, if you’ve just taken up a routine, taking time off can quickly eradicate your gains. But if you exercise regularly—several times per week for several months—it’ll take longer than seven days for your strength to evaporate. According to a 2007 study published in Archives of Physical Medicine and Rehabilitation, for athletes, “strength performance in general is maintained for up to four weeks of inactivity.”