Strength training, otherwise known as weight training or resistance training, is very different from the just-as-important stretching or aerobic exercises. No matter what your age or physical condition, strength training is recommended as a part of fitness. Strength training involves activities you do while sitting or standing in one place, such as lifting the leg, bending the arm, or working the stomach muscles. It involves any movement you can repeat 8-10 times in a row that pushes a muscle or set of muscles to exhaustion. The resistance to movement can be from weights of different sizes, from gravity, or from daily work.

Many people today don't do heavy physical work so we need at least 30 minutes of strength-training exercise three times a week to remain active and healthy.

Using weights for resistance can be tricky. With good posture and form, most young people, as well as adults, can use the exercise examples below. Begin with 1 pound of weight. You should be able to lift the weight easily the first seven times. If the movements are not easy to do, begin with 2 weeks exercise without weights, using gravity as the resistance. Gradual increases of a pound can be made once a week up to a maximum of 5 pounds total weight.

Heavier weights are not recommended for those under age 16.

All strength training should be done in a slow, controlled way to build strength. At first, repeat each movement 8-12 times for one set of exercises. After 6 weeks or so, repeat the set if your muscles don't feel exhausted.

Important points:

• Use slow, controlled movement, with good posture and relaxed joints...no jerky movements...no "locked joints."
• Do a maximum of four workouts each week... skip every other day.
• Breathe in and out... the muscles, not the exerciser, should feel exhausted!
• Do not increase weight more than once each week.

Lying-down, knees-bent, abdominal curl-ups

No weights! But this one is vital for the abdominal muscles that support the stomach and low back.

Place arms across the chest and raise shoulders off the floor using the stomach muscles. Relax slowly to the floor.

Standing or sitting strength exercises

Hold lower arms level with the floor, with palms up, holding 1 pound weights to start. Keep upper arms at the side, raising weights slowly to shoulders. Return to the start position slowly.

With arms at side and both hands holding 1 pound weights to start, raise one arm above the head and return slowly to side without other movement of the body. Repeat with other arm.

Hold arms at side with both hands holding 1 pound weights to start and palms facing back. Raise arms backwards as far as comfortable.

Hold 1 pound weights to start in each hand, touching the middle of the chest. Push one arm out straight at chest height and return. Repeat with other arm.

Hold 1 pound weights to start in both hands at shoulder height and raise both arms overhead. Return to shoulder height slowly.

Standing strength exercises

With arms at side and both hands holding 1 pound weights to start, raise body on tiptoe and hold. Return heels to floor slowly.

Without weights and holding onto wall or chair for balance, lower hips into a squatting position.