It’s hard to keep up with all of the changing news about exercise. Once a health rumor hits the news, it’s hard to ignore it, but trusting the wrong advice can hamper your efforts to stay healthy.

The truth is, most of us probably believe at least one fitness myth. Mayo Clinic’s recent “Women’s HealthSource” takes a look at some of the more common misconceptions about exercise:

FICTION: Abdominal exercises will flatten your stomach.

FACT: Crunches are great for improving posture and strengthening muscles, but they will do very little to get rid of fat covering those muscles. To do that, you need to consume fewer calories than you burn.

FICTION: Aerobic exercises will help you lose weight by speeding up your metabolism.

FACT: True, your metabolism (the rate at which you burn calories) speeds up during the workout and for a little while after. Although you will have burned some calories during your aerobic workout, adding strength training to build calorie-burning muscle will magnify your metabolic benefits.

FICTION: Exercise makes you hungrier.

FACT: Fortunately, the opposite can be true. Intense exercise can suppress your appetite, at least for a while.

FICTION: No pain, no gain.

FACT: Exercise shouldn’t hurt. A bit of muscle soreness isn’t a problem, but soreness isn’t pain. You don’t need to make your muscles “burn” to know they’re working.

FICTION: The more aerobic exercise, the better.

FACT: You don’t have to push yourself to extremes to get the benefits of exercise. A good fitness program should include stretching and strength training, as well as aerobic work. Hard work days should be alternated with light ones.

FICTION: Exercise must be strenuous.

FACT: Any movement is good for you. Don’t think “exercise”; think “physical activity” instead. Dancing, gardening and nature walks are all beneficial forms of movement.

Fitness information may seem to change almost daily, but some facts will always stay the same. Physical activity is necessary for your good health, and staying fit should never hurt.