Fitness is basically the process of doing physical activities, to keep your body in shape. Fitness can include anything from, swimming, running, exercise, weight training and aerobics. Everyone should try to incorporate some form of physical activity, into their daily lives. You don't need to run a marathon, just choose some activities, which you are comfortable with, that allow you to gradually increase your heart rate and breathing.

Why is fitness important? Because people, especially in the US, are becoming obese. Staying fit isn't about losing weight, although that maybe a by-product. You can be big and still be fit; professional football is loaded with big people, who are fit. Exercise has been shown to be beneficial, to certain problems, including, hypertension, anxiety and depression. Regular physical activity can help slow down the aging process, of the body. A regular fitness routine will improve your quality of life, not just physical, but also mental.

The bigger concern isn't why you need to be physically active, but what happens when you're not. Less active people tend to gain weight and their weight gain will put more pressure on their hearts. Without regular exercise, the heart has a greater chance of developing cardiovascular disease. A lack of physical exercise can lead to an increase in blood pressure, reduction in bone mass and limit flexibility. A lack of physical activity can cause disuse atrophy, which is a condition where the body starts to deteriorate because of non-use.

Who's responsible for your fitness? Should it be the government, because they know the Social Security system is a mess and they need you to live a long time, so they can continue to push back the retirement age? Is it the health care industry, who have more patients then they can handle and realize that the more you stay fit, the less of a chance you'll need them? Or is it your employer, who knows that a fit employee will probably be more productive at work and won't be taking a lot of sick days and costing the company money? Although those organizations will greatly benefit from your continued good health, they're ultimately not responsible for it, you are.

You normally have a lot of activity, when you're young. You're constantly running around and playing. Your parents usually have to stop your activities, so they can put you to bed. Maybe it's because you're a kid and you have all that pent-up energy, but your body seems like it can go non-stop, at that age. But, as you grow up, your activities change. Now your activities are centered around work and home and the responsibilities that come with each. Maybe that's why you lose fitness, as you age, because its not a normal part of your life. When you're young, exercise is included, whether it's recess or sports at school, or playing with your friends after school, staying active isn't a problem. But, as an adult, you need to schedule physical activities into your life.

Michael Russell Your Independent guide to Fitness.