Wall sit

Wall Sit
"Holding this position strengthens your core, quadriceps, and glutes, which in turn helps prevent pain in your low back, knees, and hips," says Vonda Wright, MD, an orthopedic surgeon and author of Fitness After 40. Stand with your back against the wall, feet shoulder-width apart, and squat down until your knees are at about 60 degrees; hold for 30 seconds—about the length of one commercial.
Plank exercise

"This move is meant to work your core, but it's amazing for your upper body," says Wright. Using your elbows and forearms to support yourself, hold a push-up position for 30 seconds; work up to two minutes.
Side plank

Side Plank
For side plank, face the television, propping yourself up on your bottom forearm. Hold for 30 seconds, working up to two minutes. Repeat on the other side.
Standing lunge exercise

Standing Lunges
"By doing lunges slowly, you increase intensity," says personal trainer Pete Cerqua, author of The 90-Second Fitness Solution. Standing, take a big step forward with your right leg. Sink halfway into a lunge (right knee at a 45-degree angle) and hold for five seconds. Sink further (your knee at a 90-degree angle); hold for five seconds. As you rise up, pause halfway and hold five more seconds, then return to a standing position. Repeat, alternating legs.

Got 10 minutes? Here's a fast fitness plan that will get you in shape inside and out