One of the biggest mistakes I see at the gym is over-exercising. I witness people doing two to three classes in a row, spending over an hour on the cardio machine and then hitting the weights for endless repetitions. The bottom line is this: Over-exercising will do more harm than good, especially when it becomes a compulsion.

A healthy exercise routine is three to five times per week with sessions lasting a minimum of 20-30 minutes to a maximum of 1.5-2 hours for the average person. An ideal fitness program consists of aerobic exercise for your heart and lungs, strength training for your muscles, and stretching to improve your flexibility.

Do you exercise too much? Here are five questions to ask yourself:

1. Are you a gym rat?

If your exercise routine lasts longer than two hours more than five days a week, you are over-exercising. While exercise is good for your body, too much has the reverse effect. Muscles do not grow while you are working out; they grow while you are resting. Muscular training stresses and damages the muscles slightly, and then your body reacts by building up the muscles in order to handle the extra work and stress. A period of 48 hours is recommended to obtain adequate rest and fuel to repair the muscles. For cardiovascular exercise, a rest period of a minimum of 24 hours is recommended to obtain adequate rest and fuel to prepare for the next workout. And every week, your body requires one to two days of complete and total rest. (yes you can still walk your dog!)

2. Are you suffering from lack of sleep?

While regular exercise is a great way to ensure a restful night's sleep, too much exercise has the opposite effect. If you find yourself stirring in the night this could be a result of over-exercise. While you are sleeping your body is trying to repair and refuel. When your body is over-exerted it goes into overdrive, like an engine that won't turn off after the key has left the ignition.

3. Do you catch every bug that goes around your office? Does it seem to take you forever to get over it?
Over-exercising stresses the body and weakens your immune system as your body is too exhausted to defend and repair itself.

4. Are you ignoring aches and pains?
Pain is your body's way of speaking to you and telling you to take it easy. While some pain may be experienced as a result of exercise, constant aches and pains such as a sore knee today, yesterday a bum shoulder, or a constant aching back is a sign of over-exercising. For more information on the different kinds of pain take a look at this post I wrote, No Pain, No Gain.

5. Are you constantly considering your input and output?
If every time you eat you are obsessing over how many calories you are eating and how much you will have to exercise to burn it off, then it's time to check in with yourself. The average female requires 2,000 calories per day to perform its normal bodily functions, such as keeping the heart beating and the lungs breathing, eliminating, and detoxifying. If you are over-exercising chances are that your body requires additional calories to repair the stress you are causing.

If any of this sounds familiar then chances are your are an over-exerciser. If slowing down does not seem like an option for you then it is time to seek guidance. Consult your doctor or a personal trainer. Over-exercising is just as dangerous as over-eating and conditions such as anorexia and bulimia. You only get one body, treat it right by keeping fit in a healthy manner and it will serve you for years to come.

Sarah Brown is a very healthy woman. She is not only a fitness instructor at Goodlife where she teaches Body Pump, Body Flow and yoga but she is also a certified nutritional practitioner. If you have a question for Sarah, leave a comment below and she will try and help, but note that not all questions will be answered.