You can do a wide range of stretching and strengthening exercises during TV commercial breaks. (Fotolia / January 8, 2014)

Can't muster the motivation to get up off the couch and exercise? Try "couchersizing" -- staying on or near your couch and exercising during commercial breaks.

"A growing body of literature connects the amount of time you spend sitting to illness and even death. Minimizing long periods of inactivity, like exercising during commercial breaks, can help reduce the risk of injury and may even help you live longer," says Kailin Collins, a physical therapist at Harvard-affiliated Massachusetts General Hospital, Boston, Mass.

You can work many different muscle groups while seated upright on a couch. Want to get your heart rate up, work your oblique muscles in your sides, and whittle your waist? Try twisting your torso from side to side for the length of a commercial break.

You can even exercise while lying on the couch: with your legs in front of you, squeeze the quadriceps for a count of 10, then relax and repeat several times; or try leg lifts while on your back to build abs, or side lifts to strengthen hip muscles.

Here are more ideas for the older couch potato set. Get your doctor's OK first, then consider trying some of these exercises during the typical 3-to-4-minute TV commercial break:

1. Sit to stand

Why it helps: This exercise works the quadriceps in the front of the thigh and gluteal muscles in the buttocks, which helps protect your ability to get up from a chair, out of a car, or off a bathroom seat.

"In addition, it's possible to use repeated repetitions of this exercise to get your heart rate up," says Collins.

How to do it: Go from sitting to standing to sitting again, 10 times in a row. Rest for a minute, then repeat.

2. Calf stretch

Why it helps: "Keeping your calves optimally flexible can keep your walking stride longer, reduce your risk of tripping over your toes, and reduce your risk for common foot injuries such as plantar fasciitis," says Collins.

How to do it: Sit on the edge of a couch with your feet flat on the floor. With one leg, keeping your heel on the floor, lift and point the toes toward the ceiling, so that you feel a stretch in your calf muscle. Hold for 30 seconds, then do the same with the other leg, three times per leg.

3. Stand on one leg

Why it helps: "Balance gets better if you practice it, which can decrease the risk of falling," says Collins.

How to do it: Holding on to the back of a chair for stability, lift one heel toward your buttocks. Hold for 30 to 45 seconds, three times per leg. To improve your balance on unsteady surfaces, try this with shoes off on a balled-up beach towel.

4. Shoulder blade squeeze

Why it helps: "This can help prevent that rounded, shoulders-forward posture that can develop from many years of sitting, especially at a computer," says Collins.

How to do it: Pinch your shoulder blades together, but not up (don't shrug). Hold for 10 seconds, then repeat 10 times.

5. Hand squeeze

Why it helps: "Keeping your grip strong makes it possible to turn a door knob, open a jar, and grasp a gallon of milk," says Collins.

How to do it: While seated upright, hold a ball (the size of a basketball) over your lap with both hands, then squeeze the ball as if you're trying to deflate it. Hold for a few seconds, then release. Repeat 10 times, rest, then do another set of 10 repetitions. You can also improve your grip strength by squeezing a small rubber ball in one hand.

Better yet, walk across the room during commercials, swinging your arms as you go. Move as much as you can, even if it's in small amounts, and you'll feel better.

6. Bicep curls

Weak biceps make it difficult to lift groceries or push yourself out of a chair. Curl can keep your muscles strong and supple.

With a physical therapist's supervision, sit on an exercise ball or chair with a 1- or 2-pound weight at your side, palm inward. Slowly bend one elbow, lifting the weight toward your chest. Keep your elbow close to your side and rotate your palm so it faces your shoulder. Pause. Slowly lower your arm, rotating it back again. Aim for eight to 12 repetitions. Repeat with your other arm. -- Harvard Health Letter

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