The American Council on Exercise (ACE) recently polled 2,500 certified fitness professionals to find out what they consider to be the top 10 mistakes made by health club members today.

Here are the surprising (and not-so-surprising) results of that study:

10. Exercising too hard: Moderate exercise is the most effective. Many people believe that they can "make up" for missed workouts.

9. Not exercising intensely enough: Picking up the pace will help members achieve changes they may not be experiencing. If their workout isn't challenging, then the lack of results can be discouraging.

8. Bad posture: People should never slouch or slump when either using machines or participating in a group exercise class. Proper posture can prevent back injuries.

7. Using momentum, rather than muscles, to lift weights: Slow, controlled movements are what builds muscle strength.

6. Lifting too much weight: If complete range of motion is not possible, then most likely the weight is too heavy. As my husband always says ... more is not necessarily better!

5. Not stretching: Stretching helps reduce injuries and increases muscle length and mobility, if done properly.

4. Skipping a cool down: Cooling down after a workout will lower the heart rate and prevent dizziness.

3. Not warming up properly: People who start their workouts full-force are likely candidates for injury and/or exhaustion. Warming up gets the blood flowing and gives muscles time to adapt.

2. Not drinking enough water: In exercise, the key is hydration, hydration, hydration! Please ensure that water is readily available in your club at all times.

1. Not consuming a nutritious "meal" within one hour of workout: The optimal time for consuming a combination of protein and carbohydrates is immediately following an intense workout session. This "window of opportunity" is imperative to the recovery of the body. A good choice is a fruit smoothie containing at least 23 grams of protein.