ALWAYS STRETCH BEFORE AND AFTER EXERCISING!
Angled pushups: Stand with your feet shoulder-width apart. Using a counter-top or table, about hip-height, lower yourself as far as you can while keeping your heals on the floor. Make sure to keep your body straight. Do not bend at the waist.
Hundreds: Lie on the floor. Slowly raise your upper and lower body off the floor. It doesn't really matter how high you lift, just be sure to keep your upper body at the same angle as your legs. Stretch your arms by your sides, directly down from your shoulders. Pump your arms up and down. Breathe in for 5 beats, breathe out for 5 beats. Repeat until you reach 100 beats. If your lower back is not strong, you can bend your knees or keep your upper body on the floor.