Your lifespan - how many years you live ? is important, but perhaps not as much so as your health span: that period of your life when you are strong, functional and able to perform everyday life tasks for yourself. Isn't that what most of us want more of in our lives - not merely years but healthy, independent, enjoyable years?

Although our knowledge on how the body ages increases the bottom line remains the same. Proper exercise has a strong positive health impact and is the key to a healthy and rewarding life. A proper exercise program containing strength training is the best strategy for retarding - even reversing ?the effects of aging.

Here are some of the benefits:

Prolong vitality by slowing or even reversing the biological deterioration processes that people typically start to suffer after about age 40, such as declining strength, glucose intolerance and metabolism slowdown.

Postpone disability by reducing your risk of such chronic conditions such as the "big three" heart disease, cancer and diabetes.

Prevent "sarcopenia" a common problem caused by a sedentary lifestyle causing a weakening of the body's muscles, particularly in the legs, with a loss of muscle mass. The ultimate price of this condition is weakness causing loss of balance, reduced mobility and frailty. A crucial first step toward making the lifestyle changes essential to extending your health span is under-standing there is an area that is crucial to how fast or slow you age.

Your Muscle Mass - The average adults problem is not excess weight as much as it is excess body fat coupled with too little muscle tissue. Simply losing weight is the wrong goal; the key is changing your ratio of body fat (inactive tissue) to muscle (active tissue).

People with a greater ratio of muscle to body fat enjoy a higher metabolism (your body's engine) and don't have to worry as much about gaining weight or about how much they eat - that active tissue burns more calories.

Most people's muscle mass declines with age accelerating after age 40. The amount of muscle tissue you have - and that you retain - is determined in part simply by how much you use your muscles.

As you age, you lose whole "motor units" - sets of muscles and nerves that work together to make your body move. For example, between ages 30 and 60, it's been estimated, people typically experience a 20% decrease in the number of motor units in the thigh.

This slows you down and partially accounts for age-related loss of strength.

To check this out stand side on to a mirror and have a good look at your upper thigh width. Does it look thinner? If it does this is a loss of muscle mass. This decline in muscle strength and size is not inevitable. So don't ever think that you are "too old" for strength training exercise. The fact is that you can regain muscle mass and strength, no matter what your age, 18 or 80, or whatever shape you are in now.

If you use your muscles frequently with proper strength training exercise, you can maintain their strength. And if you push your muscles to the limits of their capacity with the right exercise, you can actually increase their strength - no matter your age. Strength is youth and the longer you keep it the more youthful you will be.