"By Bob Greene

Before beginning any fitness program, I've always insisted that you get functionally fit first. This means that you should be in shape enough to safely and effectively perform everyday activities, like bending, lifting, twisting and walking. After all, if you can't reach into the back of a closet without pulling a muscle, how can you safely lift a dumbbell several times?

But it’s also important to stay functionally fit even after you've been active for a while to keep key muscles (your abs, back and shoulders, and lower legs) in ready-shape. The following 11 exercises condition these muscles by improving their flexibility, strength and endurance. Plus, they’re quick and easy: You can weave them into your regular workouts; an entire series takes only 10 minutes. And, you can check out our video demonstrations to make sure you're doing them properly (simply click on each move below).

Flexibility Exercises
Moves: Hamstring Stretch, Quadriceps Stretch, Upper Calf Stretch, Middle and Low Back Stretch, Lower Calf Stretch
Stretching your lower leg muscles improves your flexibility because it allows muscles and joints to use their normal range of motion. Other perk to increasing your flexibility: You’ll reduce your risk for injury and prevent post-workout soreness. For each stretch, hold for five seconds then relax for five seconds. Complete at least three stretch-and-relax cycles. Remember not to bounce and to breathe deeply but comfortably during each stretch.

Abdominals
Moves: Basic Crunch, Twisting Trunk Curl Crunch, Upper Abdomen Crunch
You may be concentrating on a flatter tummer whenever you do your crunches, but you can't overlook another very important benefit to the exercise: It also helps keep you healthy. Crunches help strengthen core muscles, which are involved in almost every movement you make. For example, anytime you lift something, whether it’s a piece of paper or a 10-pound dumbbell, it’s your abs that stabilize your body and protect your back. Note that these exercises are crunches and not sit-ups. Crunches raise the torso only about 30 to 45 degrees, and the knees are always bent. This helps protect the back from unnecessary stress. Perform each of these crunches 15 times at least three times per week.

Back and Shoulder
Moves: Arm and Leg Raise, Shrug Roll
Strengthening your back and shoulders will help improve your posture. It will also help protect your body when you’re walking or running. Once your reach Phase 3, perform these moves while holding five- or 10-pound dumbbells.

Lower Leg
Move: Heel Raise
Consider this a two-for-one move: It strengthens both your calves and shins. That’s important because these muscles help stabilize your body when you stand and perform activities like walking and climbing stairs. You’ll also reduce your risk for shin splits, an inflammatory condition that affects about 60 percent of people who begin a walking program. In Phase 3, perform heel raises while holding dumbbells. Begin with a five- or 10-pound weight in each hand, and increase the weight when you can easily complete 15 repetitions."