The plank helps to strengthen and protect your back. This popular core-training exercise also conditions your abdominal muscles. The abdominals, obliques and back muscles make up your core. Core-training exercises strengthen the muscles that stabilize your torso. A strong core supports your spine, internal organs, posture and the power of all your movements. Practice performing the plank exercise on most days of the week for a stronger back and firmer midsection. You need upper-body strength for the plank exercise. Consult your doctor before beginning any exercise program.
Warm up with 5 to 10 minutes of light exercise, such as marching in place or using a stationary bicycle. This increases the blood flow and oxygen supply to your muscles and prepares your body for more strenuous activity.
Stretch out face-down on the floor. Position your elbows directly below your shoulders. Press your hands and forearms against the floor, keeping your arms close to your body. Tighten your thigh muscles and point your toes toward your knees to prepare them to support your weight.
Engage your abdominal muscles to raise your legs and torso from the floor. Support your weight on your toes and forearms. Keep your neck, back, buttocks and legs in a straight line, similar to a plank of wood.
Breathe naturally and hold the plank position for at least five seconds. Keep your back straight throughout the exercise. Keep your knees straight, but not locked.
Slowly lower your body to the floor, keeping your back and legs straight. Relax and breathe deeply.
If you find it difficult to support your weight, perform resistance training at least three times a week for 20 minutes. Lifting weights or engaging in a body weight exercise program develops strength and helps prevent muscle loss. Performing modified pushups -- from a kneeling position -- will help you strengthen your arms so that you'll be able to raise your body into the plank position without strain. If you experience back pain during the plank exercise, stop immediately and consult your doctor.