By training a minimum of 20 minutes, three days a week, you will develop and maintain cardiovascular fitness. Any number of exercises such as walking, aerobics or dance can train our cardiovascular system to continuously deliver the oxygen needed to keep our muscles operating at prime levels. The next aspect of physically fit bodies is muscular strength. The muscles in our body have to work to maintain a degree of health and fitness. Muscles that are not continually worked and strengthened will weaken and cause atrophy.
Weak muscles can lead to poor posture, aches and pains.
The body is a highly tuned and balanced biological machine that has to be trained in a balanced way. When strengthening the muscles of the body it is vital that you work ALL the muscles. Don't focus on the ones that make you look good, such as the abdominals, pectorals, or ever-popular gluteus maximus. Developing huge chests and firm butts may look great but can lead to problems down the road such as lower back problems and tight hamstrings. Working on a Nautilus or Sprint line of exercise machines is an excellent training regimen that works all the major muscles of your body.