Myth #1 - Running on the treadmill puts less stress on your knees than running on asphalt.
Running is a great cardiovascular workout, but it does impact the knees.  The impact is the force of your body causing stress on your joins - and that force remains the same whether you're on the treadmill or asphalt.  To avoid injury, mix up your cardio workout.  Try swimming, biking, and the elliptical.  By changing things up you will not only stave off boredom, but you will also lessen the impact on your joints so that you'll be able to run for many, many more years!

Myth #2 - Sit ups and crunches get rid of "belly fat."
While abdominal exercises are great for muscle toning and improving posture, most experts agree that they do not burn fat from your mid-section.  Your body chooses where you will burn fat from first - and this process is different for all of us!  Create (or ask your trainer to create!) a cardio and toning program to help burn overall body fat and tone your muscles.  Once you burn off that belly fat with cardio, then you'll be able to see the muscles you've created with crunches and other abdominal exercises!

Myth #3 - You continue to burn calories for hours after working out.
This statement is true - to a degree.  Your metabolic rate is raised during your workout, and stays slightly elevated for a few hours afterwards.  In fact, you will only burn about an extra 20 calories during this period, says professional triathlete and personal coach Eric Harr, author of The Portable Personal Trainer.   Some exercise enthusiasts will overeat after a big workout, thinking that they are burning off the ice cream and cookies... don't let yourself fall into this trap!

Myth #4 - If you're not working up a sweat, you're not working hard enough
The fact that your body is sweating does not tell you that your working hard - it's telling you that you body is cooling itself.  It is possible to burn calories without breaking a sweat (as many people enjoy doing!) such as walking or doing some light weight training.

Myth #5 - Muscle can turn into fat
Muscle and fat are two different tissues with two different functions, they cannot 'turn into' each other.  If you stop exercising, you will lose the muscle that you gained.  If you have unhealthy habits, you will gain fat.

Myth #6 - Stretching before exercise prevents injury and enhance your performance
Studies have not conclusively shown that stretching BEFORE exercise can prevent injury or enhance performance.  Stretching does, however, make your workout (twisting, lifting, bending, etc) easier!  Try doing a smaller version of the movements and exercises that you will do in your real workout.  And, be sure to stretch after your workout while muscles are warm!

Myth #7 - No pain, no gain
Of all the rumors out there, we've all probably heard this one!  While you may feel soreness one to two days after working out, you do not want to feel pain during your workout.  If a fitness activity hurts while you are doing it, you may be doing it wrong or already have an injury.  If you are in pain, stop and rest to see if the pain goes away.  If it doesn't, you may need to stop your workout for the day (possibly see a doctor!).  If you felt pain during a class or while on a machine, ask the instructor or trainer for help before trying it again!