11 fitness myths that are doing more harm than good

Whether you want to tone up, slim down, or boost your mood, you've likely taken a stab at tweaking your fitness routine.

Unfortunately, there's a lot of workout advice out there that won't help you meet your goals and could actually do more harm than good.

Here's an overview of some of the most enduring workout myths and misconceptions, as well as the real science that can help you meet your fitness goals in a healthy way.

SEE ALSO: 12 ways one type of exercise is the closest thing to a miracle drug we have

DON'T MISS: How often you need to exercise to see results, according to the scientist behind the viral 7-minute workout

Myth: To stay in shape, you only need to work out once or twice a week.

Truth: Once or twice a week won't cut it for sustained health benefits.

For your workouts to produce real results, you should be exercising 3-5 times a week, Chris Jordan, the exercise physiologist who came up with the 7-minute workout, told Business Insider.

His insight is bolstered by a new study published in January in the American Heart Association's journal Circulation that found that the best results for heart health were gleaned when participants worked out 4-5 times a week.

Myth: The best time to work out is first thing in the morning.

Truth: The best time for a workout is whatever time allows you to exercise most consistently. Ideally, you want to make physical fitness a daily habit, so if late-night trips to the gym are your thing, stick with it. If you prefer a morning run, do that instead. 

Don't have a preference? Some research suggests that working out first thing in the morning might help speed weight loss by priming the body to burn more fat throughout the day.

Myth: Weight lifting turns fat into muscle.

Truth: You can't turn fat into muscle. Physiologically speaking, they're two different tissues. Adipose (fatty) tissue is found under the skin, sandwiched between muscles, and around internal organs like the heart. Muscle tissue — which can be further broken down into three main types — is found throughout the body. 

Weight training helps build up the muscle tissue in and around any fat tissue. The best way to reduce fat tissue is to eat a healthy diet that incorporates vegetables, whole grains, lean proteins and healthy fats like those found in olive oil and fish.