Lie on the ground and place your hand on the ground a little wider than shoulder width apart. Keep your body in a straight line as you push up. Bring your body back down until your arm forms a 90 degree angle. Repeat. Common mistakes are arching your back or letting it sag and letting your forehead touch while your butt stays in the air.
Too hard? Keep your knees on the ground.
Sit on the floor with your feet flat and your knees bent 90 degrees. Hold your hands together in front of you. Contract your abs. Lift your feet off the floor. Rotate your torso from side to side.
Lay on the ground with your arms extended behind your head. Keep your legs straight and lift them up while raising your upper body off of the floor. Reach for your toes with your hands. Squeeze your abdominal muscles as you reach for you toes. Slowly lower yourself back down to the floor and repeat.
Start in the push up position but bend your elbows and rest your weight on your forearms. Form a straight line from your head to your feet. Keep your abs tight. Hold the position for 30 seconds
Same as above.
** If you have knee problems, skip this.
Place your feet shoulder width apart, face forward and hold your chest up and out. Clasp your hands in front of you. Sit down like there was a chair under you. Keep lowering yourself until your thighs are parallel with the floor. Keep your knees over your ankles and your weight on your heels. Return to the starting position.
Stand with your back against a wall. Slide your feet forward and your back down until your thighs are parallel to the floor. Hold for 30 seconds. If 30 seconds is too hard, do what is comfortable for you. Likewise, if it is too easy, then go longer.
Same as above.