Step forward, keeping your back straight, and bend your knees at a right angle. Go down until your back knee is almost touching the ground. Return your feet together and step out with the opposite leg repeating the process. To increase difficulty, use free weights while doing the exercise.
With your feet a little more than shoulder- width apart, bend your legs to a 90 degree angle. Keep your back straight and your chest up.
Stand on the edge of a step and raise onto your toes and then back down. Try to complete 25 calf raises, increasing as you become more comfortable.
Push-ups are a great exercise for building upper-body strength. If you are unable to perform the regular push-ups, then put your knees to the ground and do your push-ups from that position.
You need a platform of some kind that is about a foot or two off the ground, like folded mats. Place your hands on the mats with your body straight out in front of you. Bend your arms until your body is almost touching the ground, and then push back up.