- Help you lose weight, especially fat weight.
- Improve your bodies ability to maximally uptake oxygen anddeliver oxygen to your working muscles (defined as your VO2 Max). This measure is generally regarded as the best measure of your physical fitness level.
- Lower your resting heart rate, by allowing your heart to pump more blood per beat. This means your heart is not working as hard when you are at rest.
- Lower or help control your blood pressure, both systolic and diastolic. This is especially important for people with high blood pressure-hypertension.
- Lower your Body Mass Index (BMI). This is the ratio of body weight (in kilograms) to height (in meters). Increased BMI is associated with an increase in morbidity and mortality.
- Reduce total cholesterol. This includes lowering LDL-the bad type of cholesterol, and increasing HDL-the good type of cholesterol.
- Reduce circulating levels of triglycerides. This is the amount of free fatty acid found in the blood.
- Improves the functioning of your immune system.
- Reduce the risk of heart disease.
- Increases insulin sensitivity to prevent against type II diabetes (adult onset diabetes).
- Reduce the risk of having a stroke.
- Increase your level of muscular strength.
- Increase your stamina and ability to do continuous work.
- Increase or maintain your bone mineral density to prevent osteoporosis.
- Increase muscular endurance.
- Help you maintain your resting metabolic rate to prevent weight gain.
- Provide protection against injury.
- Maintain or improve joint integrity.
- Improves your balance and coordination.
- Reduce the risk of developing colon cancer.
- Reduce the risk of developing breast cancer.
- Reduce your level of anxiety.
- Help you manage stress more effectively.
- Improve your positive self-esteem and confidence.
- Help alleviate depression.
- Improve your appearance.
- Help you relax.
- Combat the likelihood of many degenerative problems.
- Improve your overall quality of life.
- Teach you about goal-setting and dedication.
- Can assists in efforts to stop smoking.
- Help to relieve and prevent migraine headache attacks.
- Can help you sleep more restfully.
- Help improve your immune system.
...to name a few reasons
Hope that helps.