Keeping fit is such a challenge nowadays. Busy work schedules, family pressures and financial limitations have classified fitness club memberships as a luxury that many can ill-afford. Hiring personal trainers are even more costly and quite frankly, limited to those whose earnings put them in the upper echelon of society (read: business moguls, media personalities and Hollywood stars).

But staying fit and healthy is everybody's concern. Societal obligations shouldn't be used as excuses where exercise is the issue. If gym memberships and hiring personal trainers comprise your idea of fitness, then you're taking a very narrow view. The truth of the matter is that exercise can be done wherever you're comfortable and whenever you make time for it.

With bodyweight training, you need nothing more than your body to develop a well-toned physique, lose weight and increase strength. Here are some exercises you can do wherever, whenever to keep you physically fit and healthy:

1. Plyometrics. These are dynamic movements that you can do twice a week to develop speed, agility and coordination. Reminiscent of the leaps and jumps you used to do when you were kids, plyometrics are fun to do. Make your foot touch the ground about 80 times at first and double that as you improve your stamina. Some plyometric exercises you can do are power skips and tuck jumps. To do power skips, push yourself as high as you possibly can, driving your leg up to chin level as you skip forward. When you do tuck jumps, begin in a standing position keeping your feet shoulder width apart. Jump as high as you can explosively, pulling your knees into your chest as you do so. Straighten your legs and land softly on the balls of your feet on the way down. Perform another tuck jump as soon as your feet lands on the ground.

2. Wall Sits. If you want to develop strength and endurance for your quads, glutes and calves, wall sits are your best bet. It's a relatively simple exercise but getting the form right can be a challenge. Start by putting your back against a wall with your feet shoulder width apart and two feet from the wall. Gradually slide your back down the wall until your thighs become parallel to the ground, keeping your knees directly above your ankles. With your back flat against the wall, stay in this position for 20 to 60 seconds. Rest for about 30 seconds before going at it again for three more times. A burning sensation in the quads is normal, but pain in the knee or kneecap isn't. Stop the exercise right away if you experience it.

3. Supermans. An excellent way to develop core strength, you begin supermans by lying on your stomach with arms and legs stretched out. Lift your arms and legs about five inches off the ground and hold this position for about 3 seconds before lowering down. Repeat. You can also alternate your arms and legs for this exercise.

With these bodyweight exercises, you can stay fit and healthy wherever you are whenever you can!