When it comes to the Big Three of exercise - cardiovascular, strength and flexibility training - it's pretty clear which one can get overlooked. After all, while we prize cardiovascular and strength training for their role in helping us lose weight, build muscle and get fit, the benefits of flexibility training are less immediately alluring.

However, as the population ages, more of us are learning to appreciate the rewards of stretching. Staying limber can offset age-related stiffness, improve athletic performance, and optimize functional movement in daily life. Research shows that flexibility training can develop and maintain range of motion and may help prevent and treat injury. In fact, the American College of Sports Medicine has added flexibility training to its general exercise recommendations, advising that stretching exercises for the major muscle groups be performed two to three days per week.

How can you include an effective flexibility workout in your fitness program? Here are some guidelines:

Think in Terms of Serious Flexibility Training, Not Just Brief Stretching. Squeezing in one or two quick stretches before or after a workout is better that nothing, but this approach will yield limited results. What's more, generic stretches may not be effective for your particular body. The more time and attention you give to your flexibility training, the more benefits you'll experience. A qualified personal trainer, physical therapist or health professional can design a functional flexibility program specifically for you.

Consider Your Activities. Are you a golfer? Do you ski, run or play tennis? Do your daily home or work routines include bending, lifting or sitting for long periods? Functional flexibility improves the stability and mobility of the whole person in his or her specific environment. An individualized stretching program is best to improve both stability (the ability to maintain ideal body alignment during all activities) and mobility (the ability to use full, normal range of motion).

Pay Special Attention to Tight Areas. Often the shoulder, chest, hamstrings and hips are particularly tight, but you may hold tension in other areas, depending on your history of injuries and the existing imbalances in your muscle groups. Unless you tailor your flexibility training to your strengths and weaknesses, you may stretch already overstretched muscles and miss areas that need training.

Listen to Your Body. Stretching is an individual thing. Pay attention to your body's signals and don't push too far. Avoid bouncing or jerking movements to gain momentum; this approach can be dangerous.

Instead, slowly stretch your muscles to the end point of movement and hold the stretch for about 10 to 30 seconds. Older adults, pregnant women and people with injuries will need to take special precautions.

Get Creative. Varying your flexibility training can help you stick with it. You can use towels, resistance balls and other accessories to add diversity and effectiveness to your stretching.

Warm Up First. Don't forget to warm up your muscles before you begin. Walking briskly for 10 to15 minutes is a simple way to do this.

Find a Flexibility Class That Works for You. Classes that include stretching are becoming more popular and more diverse. Some combine cardiovascular and strength components with the flexibility training; others focus exclusively on stretching.

Stretch Your Mind and Body. Did you know that your emotional state may affect your flexibility? If your body is relaxed, it will be more responsive to flexibility training. Listening to music and focusing on your breath can help you relax as you stretch. You may also want to explore yoga or Pilates. In addition to stretching, classes in these disciplines may include relaxation, visualization and other mind-body techniques designed to reduce stress and increase mindfulness.

It's Not Just for Wimps. Forget the idea that stretching is just for elderly, injured or unconditioned people. Many Olympic and professional athletes rely on flexibility training for peak performance.

Do It Consistently. It doesn't help to stretch for a few weeks and then forget about it. Integrate regular stretching into your permanent fitness program. For inspiration, look to cats and dogs - they're dedicated practitioners of regular stretching and you rarely see them getting the kind of joint or muscular injuries that humans get!

Shoulder and Trapezius Stretch
** Stand upright with shoulders back, chest out, and feet hip-width apart.
** Clasp your hands behind your buttocks.
** Slowly lift your hands up and away from your body until they have reached the furthest comfortable position.
** Keep your chest out and your chin in without hunching over.
** Once you feel a comfortable stretch in your chest and anterior shoulders, hold this position for at least 15-30 seconds.

Lying Quadriceps Stretch
** Lie face down on a mat.
** Lift your right leg up towards your buttocks.
** Reach around with your right hand and grasp your foot. Slowly pull downwards, stretching your quadriceps to the furthest comfortable position.
** Hold this position for at least 15-30 seconds.

Shin Stretch
** Using a wall or chair as support, place your left foot behind your right foot, with the top of your left foot on the ground.
** Extend the bottom of your left shin as far forward as possible. Slowly lower yourself by bending both legs.
** Once you have stretched your anterior tibialis to the furthest comfortable position, hold for at least 15-30 seconds.
** Switch legs and repeat.

Hip, Gluteus and Back Stretch
** Sit on the floor with both of your legs extended in front of you.
** Bend your right leg over your left leg, keeping your right foot flat on the floor outside the left knee.
** Place your left elbow on the outside of your right knee, and extend your right arm behind you with your palm flat on the floor for support.
** Slowly twist your upper body to the right while looking over your right shoulder.
** Lightly apply pressure with your left elbow on the outside of your right knee as you twist. Be sure to keep your upper body straight.
** Once you feel a comfortable stretch in your hips, buttocks, and lower back, hold this position for at least 15-30 seconds.
** Switch sides and repeat.

Calf Stretch
** Put the sole of the top half of your right foot against the wall. Slide your right heel as close towards the wall as possible.
** Slowly lean forward towards the wall stretching your calves. Once you have stretched your calf to the furthest comfortable position, hold for at least 15-30 seconds.
** Switch legs and repeat.