Slide show: Weight training exercises for major muscle groups

Weight training can boost your strength, tone your muscles and help you lose fat. Ready to start a weight training program?

Warm up with five to 10 minutes of stretching or brisk walking. With your doctor's OK, choose a weight or resistance level heavy enough to tire your muscles after about 12 repetitions. With the proper weight, a single set of 12 repetitions can build muscle just as efficiently as can multiple sets of the same exercise.

To give your muscles time to recover, rest a day between exercising each specific muscle group. Remember to complement your weight training routine with daily aerobic activity. Overall fitness will soon be yours!

Free weights are versatile weight training tools. The dumbbell press works the pectoral muscles on the front of your chest.

Lie on your back with your knees bent and your feet flat on the floor or weight bench. Outstretch your arms with your elbows bent to 90 degrees and your palms facing forward. Slowly press the weights upward until your elbows are almost straight. Don't lock your elbows or push with your feet. Return to the starting position, being careful not to drop your elbows below the surface of the bench. Repeat.

This weight training exercise is known as the "bent over" row. It works the muscles in the back of your shoulders and your upper back.

Start with one knee resting on the weight bench. Lean forward, supporting yourself with your hand. Hold the weight in your other hand with your arm hanging straight down, as shown here. Pull the weight up until your upper arm is parallel to the weight bench. Return to the starting position. Repeat.

This exercise strengthens your biceps — the front muscles of your upper arms.

Stand up straight with your feet about shoulder-width apart and your knees slightly bent. Hold the weight at your side with your palm facing upward. Keep your abdominal muscles tightened and your back straight.

Slowly curl the weight up by bending your elbow. Hold your wrist straight throughout the movement, and keep your upper arm aligned with your body. Slowly lower the weight to the starting position. Repeat.

This exercise strengthens your triceps — the back muscles of your upper arms.

Lie on your back with your knees bent and your feet flat on the floor or weight bench. Point your upper arm to the ceiling, with your elbow bent to 90 degrees. Slowly straighten your elbow, moving the weight upward. Return to the starting position. Repeat.

This exercise uses an ankle weight to target your quadriceps — the muscles on the front of your thighs.

Apply an ankle weight to your ankle. Then sit on a chair or weight bench, with your feet dangling in a relaxed position and your knees flexed at about 90 degrees. In a slow, controlled motion, raise your leg until it's almost fully extended, pause, and slowly lower your leg to the starting position. Repeat.

You can do the same exercise on a knee extension machine.

Weight machines can help you work your muscles in various ways. The leg press targets the quadriceps and hamstrings in your thighs, as well as the gluteal muscles in your buttocks.

Adjust the seat of the machine so that your legs are comfortably bent. Place your feet on the platform slightly greater than shoulder-width apart. Pushing through your heels, slowly straighten your knees. Don't arch your back. Return to the starting position. Repeat.

This exercise targets your hamstrings — the muscles at the back of your thighs.

Lie facedown on the weight bench. Position the pad just above your ankles. Keep your upper body stable, but relaxed. Use the handgrip for support only. Slowly bend your knees, pulling your feet toward your buttocks. Only go as far as you can without moving your pelvis or spine. Don't pull with your arms, or arch your neck or lower back. Return to the starting position. Repeat.

Weight training includes exercises using your own body weight. Push-ups work your chest, arms, shoulders and upper body.

Lie facedown with your palms on the floor at shoulder level, your fingers pointing forward and your arms extended. Bend your toes to keep the bottoms of your feet perpendicular to the floor. Keeping your back and legs straight, lower yourself until your body is parallel to the floor. Rest your body weight on your palms and toes. Raise yourself to the starting position. Repeat until you can't raise yourself up or your body alignment deteriorates.

The calf raise works the calf muscles at the back of your legs.

Stand with your feet slightly spread apart. Slowly rise up onto your toes, shown here. Pause, then return to the starting position. Keep your abdominal muscles tight and your back straight. Repeat until you can't raise yourself up.

For greater challenge, hold weights at your sides with your palms facing your body while you rise up onto your toes.

Squats work the quadriceps at the front of your thighs and the gluteal muscles in your buttocks.

Stand with your feet slightly greater than shoulder-width apart and your toes pointed ahead. Slowly lower your body, bending through the hips, knees and ankles, shown here. Stop when your knees are bent to 90 degrees. Maintain a normal back arch throughout the movement. Return to the starting position. Repeat until you can't lower yourself anymore.

For greater challenge, hold weights at your sides with your palms facing your body while you squat.