Myth: 

Your muscles will turn to fat when you stop exercising.

Have you ever had a broken bone, perhaps a broken leg? 

When the doctor removed the cast from your leg, did you see a big gob of fat where your muscles once were?

NO!

The muscles had atrophied, and perhaps there was some loose skin. But  muscle does not turn into fat.

Muscles do have the "use it or lose it" quality, meaning they will waste away if not used.

However, muscle tissue and fat tissue are separate and distinct. One cannot turn into the other.

Perhaps the origin of this popular myth is when someone maintains an active lifestyle and then, upon becoming more sedentary, maintains the same caloric intake. This would result in both muscular atrophy and fat accumulation.

Myth: 

You will be healthier if you avoid fats, sodium and sugar altogether.

Diabetes, hypertension and water retention are three cases where this is a valid point indeed. If your physician has asked you to shun any of these, then please, by all means, do so.

However, your body needs fats, particularly healthy Omega-3 fats found in fish. Fresh fruit, which is definitely an important part of your diet, contains sugar. And salt is required for many vital bodily functions.

So unless your physician has prescribed a diet that excludes any of these three items, moderation — not elimination — is the key.

Myth: 

If you stay consistent with your exercise program, then you will eventually have success.

Following a plan is important. However, are you meeting your goals from following this plan?

Results aren't usually apparent overnight. However, you should not blindly follow a program that is not helping you get where you want to be. 

If you and your trainer set realistic goals, and take follow-up measurements every two to four weeks, then you can determine if you are on the right path.

It is a good idea to change training programs every four weeks, both for maintaining your interest and to keep your body responsive.

Remember: a fitness program is something that you and your trainer design together, with his or her knowledge and your goals.

Myth: 

Three square meals per day is the golden rule of good health.

Actually, 5 or 6 meals daily, spaced out 2-3 hours apart, is the best strategy.

Rather than just eat by the clock or when you are hungry, you should attempt to consume all your meals in a 15-18 hour period. This allows you to maintain a consistent level of energy and blood sugar.

Each meal should contain the proper ratio of protein, carbohydrates, and fats. Base your meals on what you will be doing for the next three hours. For example, you will be expending more calories during a workout than watching television, so your pre-workout  nutrition would have more calories than your last meal of the day.

And don't forget training is an important part of health!

Myth: 

The only reason a person would have a high Body Mass Index (BMI) is because they are obese and unhealthy.

BMI, long a staple of the medical and fitness community, has been coming under greater scrutiny. Although it can be a good guide and measurement tool, it only considers height and weight.

Consider any popular bodybuilding figure. They would be considered very high on the BMI chart. But they don't look fat. Why? BMI assumes we are all the same shape and body frame size.

A more telling measurement is body fat percentage: what portion of your body is made up of storage fat, and what portion is lean body mass (muscle, bone and organs).

Don't ignore BMI, but do take it in context with other measurements.