A convenient at-home exercise program you can stick to three times a week is certainly better than going to the gym once a month. Here are several suggested exercises you should try to weave into your everyday life. And also keep in mind that you should walk for at least 30 to 60 minutes every day.

Whenever you engage in any kind of exercise, you should feel the intended muscles being activated. You should not feel lower-back pain or pain in any area the exercise is NOT intended to affect. Also, always be in control and don't do extra repetitions of any exercise when that would mean not maintaining perfect form. And make sure that you consult a physician prior to starting any exercise program.

PLANK AND SIDE PLANK

Targets: Abdominals, scapular stabilizers, back extensors.

Equipment: None.

Starting position: Begin on your hands and knees with your hands a little more than shoulder width apart and slightly in front of your shoulders.

Movement: Extend one leg at a time, coming to balance on the balls of your feet as in the "up" part of a push-up. Contract your abdominals so that your back is parallel to the floor. Keep your head and neck in line with your spine.

Side plank: From the plank position bring your feet together so that they are touching one another and roll onto the outside of your right foot while lifting your left arm up toward the ceiling. Repeat to the other side.

How many: Hold starting for 15 seconds, building up to 60 seconds, and do one repetition.

PUSH-UP

Targets: Pectoralis major, front deltoid, triceps, chest, abdominals.

Equipment: None.

Starting position: Begin facedown with your hands a little wider than shoulder width apart and slightly in front of your shoulders. Keep your legs together and balance on the balls of your feet. Contract your abdominals so your back is parallel to the floor. Keep your head and neck in line with your spine.

Movement: Inhale as you lower your chest as close to the floor as possible. Exhale as you squeeze your chest muscles inward to push back up to starting position.

How many: Three sets of 10 repetitions.

SQUAT

Targets: Buttocks, hamstrings, quadriceps, legs.

Equipment: None, or you can use dumbbells.

Starting position: Stand with your feet a little wider than shoulder width apart and your arms hanging at your sides. Keep your torso erect and your body weight over your heels.

Movement: Inhale as you bend your knees and lower your body as if to sit in a chair until your thighs are as close to parallel to the floor as possible. Do not go lower than this or you will put too much stress on your knees. Exhale as you squeeze your buttocks and come back to the starting position. Always keep your knees in line with your second toe. (I realize that "your second toe" may sound strange, but if your knees extended to your big toe, it would be too far.) Do not let your knees extend over your toes.

Variation: Hold dumbbells in your hands.

How many: Two sets of 10 repetitions.

BALL LEG RAISE

Targets: Abductors, buttocks, torso, core.

Equipment: Exercise/stability ball (25 centimeters).

Starting position: Lie faceup on the floor. Hold an exercise ball between your knees, keeping your knees above your hips and your arms at your sides, palms facing up.

Movement: Exhale as you lift your hips and pull your knees toward your chin with the ball between your legs. Make sure to concentrate on using your stomach muscles to bring the ball toward your chin. Inhale as you slowly lower to starting position.

How many: Two sets of 10 repetitions.

SCISSOR KICKS

Targets: Torso, core — including abdominals.

Equipment: None.

Starting position: Lie faceup on the floor with your hands at your sides, palms facing the ground. Pull your abdominals in so you can lengthen your back.

Movement: Lift your legs about 3 inches off the floor. Exhale as you rapidly move your legs up and down (your right and left legs are moving in opposite directions) in a scissor-like motion between 3 and 6 inches. Inhale as you slowly return to starting position.

How many: Two sets of 10 repetitions.

CAT CAMEL

Targets: Spinal mobility, mid- to lower back, hips.

Equipment: None.

Starting position: Start on your hands and knees. Make sure your knees are directly under your hips and your hands are directly under your shoulders.

Movement: Inhale and look up as you let your stomach soften toward the ground while arching your back as if forming the letter "U," and letting your buttocks lift toward the ceiling. Then, as you exhale, let your head and buttocks round toward the floor so that your spine humps and your stomach is concave. Repeat inhaling and exhaling with slow movements.

How many: Two sets of 10 repetitions.

Charles Stuart Platkin is a nutrition and public health advocate and founder of www.DietDetective.com.