Five core options
If you find it awkward (or uncomfortable) to get up and down off the floor, you can do these moves at the end of the workout just before you stretch.

1. Bird dogs: Kneel on hands and knees (on a mat or pad); be sure that your shoulders are directly over your hands and your knees are over hips. Keep your back flat. Simultaneously raise your right arm out in front and extend your left leg behind until both are parallel with the floor. Then bring them in toward one another directly under the trunk — elbow toward knee and knee toward elbow. Only come in as far as you can, keeping the back straight.  Immediately switch and do the same movement on the opposite side. Continue to alternate sides. Try to move the arms and legs without moving the back. Works the back extensors, the hamstrings, gluteals and core stabilizer muscles.

2. Reverse curls: Lie on your back (on a mat or pad) and lace the fingers together behind your head to support your neck. Cross your feet at the ankles and bend your knees. Hold your head up slightly off the floor, but don’t move it. Using your lower abdominals, lift and roll your hips and legs up off the floor and toward your head. Keep the movement small, slow and controlled. Avoid swinging the legs. Works the abdominals.

3. Crunches with feet on the step: Lie on your back with your knees bent and your feet on a step (or your calves and feet resting on the seat of a chair). Your thighs should be at a 90-degree angle from your torso. Lace your fingers together and place them behind the head to support the neck. Flex the feet and keep the toes up. Lift the head, neck and shoulders up off the floor, drawing in the abdominals, and slowly lower down. Works the abdominals.

4. Alternating elbow to knees on back: Lie on your back (on a mat or pad) with knees bent, feet on the floor. Lace the fingers together and place them behind the head to support the neck. Lift your head, neck and shoulders and bring your right elbow toward your left knee. Keep your lower and mid back on the floor. Do not try to touch, just lift and bring them close to one another, keeping the back on the floor. Lower down and immediately switch to the other side. Continue alternating sides. Works the abdominals and core stabilizers.

5. Back extensions: Lie face down on a mat or pad. Bring your arms alongside your body. Tuck your chin in toward your chest and point your face straight down. Lift your head, neck and shoulders several inches off the floor, hold for a second and return to the starting position. Keep the lower body on the floor. Only work in a pain-free range of motion. Works the back extensors.

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