Exercise can have a surprising number of benefits: it can improve your cardiovascular fitness and muscular endurance, which translates into an increase in energy; it can dramatically reduce the risk of coronary artery disease; it may also help lower blood pressure and cholesterol levels, and aid in weight control; and it appears to give self-esteem a measurable boost, and in general to improve your sense of well-being.

You can derive these benefits at any age, and indeed, exercise - or at least staying physically active - appears to be increasingly important the older we get. Many of the problems commonly associated with aging - increased body fat, decreased muscular strength and flexibility, loss of bone mass, lower metabolism, and slower reaction times - are often signs of inactivity that can be minimized or even prevented by exercise.

The Elements of Fitness
Fitness is defined as "the ability to carry out daily tasks with vigor and alertness, without undue fatigue, and with ample energy to enjoy leisure time pursuits and to meet unforeseen emergencies." Yet physical fitness means different things to a dancer, marathon runner, lumberjack, mailman, and weight lifter. It's also a relative term, in that you may be fitter than you were last year or than your neighbor, but there's no clear-cut point at which you are "fit". One fact is clear, though: if fitness is the goal, exercise is the way to get there.

There are four basic elements of physical fitness: cardiovascular endurance, muscular strength, muscular endurance, and flexibility. Each can be measurably improved with regular exercise. But keep in mind that exercising to build fitness is not the same thing as working out to improve athletic performance. To be truly fit, you should develop all four elements, not just one or two.