While most people are aware of the health benefits of keeping fit after 50, many aren't certain what a well-rounded program entails.  In a recent report, the American College of Sports Medicine recommended flexibility exercises (stretching)---- along with aerobic (cardiovascular) exercise and strength training for all older adults.

'The older one gets, the stiffer one gets, so it becomes more and more important to maintain and increase flexibility through stretching." says Barbara deLateur, M.D., Professor and Director, Physical Medicine and Rehabilitation at Johns Hopkins.  As we age, flexibility decreases owing to loss of water content in the intervertebral disks and other age related tissue changes.  Research has shown  inactivity also plays a role: muscles need to be used regularly to keep them from weakening, and stretched regularly to keep them from tightening.

If you're inflexible, it's more difficult to perform everyday activities like putting on shoes and socks and getting in and out of the car, and falls are more likely.

Relaxed body, alert mind

There are two major types of stretching: static   (passive) or dynamic (active).  Static involves slow, gradual, controlled elongation of the muscle through the full range of motion.  Dynamic stretching employs a bouncing technique.  Static stretching is the more frequently recommended method since it is less stressful and easier to perform without injury.  Dynamic stretching is generally reserved for sports training.  It is not recommended for older adults or non-athletes.

When properly performed, static stretching increases flexibility by encouraging joints and muscles to utilize their full range of motion.  The result is improved balance, agility, better posture, and less susceptibility to fatigue and pain.  A recent study in the Journal of Gerontology evaluated 103 men and women aged 65 years and older who were free from cardiovascular disease and musculoskeletal problems.  Over a 12-month period, those who performed static stretching exercises reported greater improvements in levels of generalized body aches than those who underwent strength training.

Static stretching also enhances physical performance, since flexibility muscles react faster and with more force than inflexible ones.  It can also help people who are physically and emotionally tense to reduce anxiety, muscle tension, blood pressure, and breathing rate. The resulting mental and physical relaxation may enhance mental alertness and minimize the risk of joint injuries, muscle strains, and sprains.  Most experts believe less flexible muscles and connective tissue restrict joint mobility, boosting the likelihood of injury.  But there are no definitive data to support this assumption.

Safety first

Static stretching is considered beneficial for almost everyone, regardless of their general health.  But if you have strained muscles; any back, neck, bone or joint problems such as rheumatoid arthritis, osteoarthritis, osteoporosis, or compression fractures (breaks caused by ordinary forces on weakened bones); or have had a hip or knee replacement, consult your doctor before beginning a stretching program.  People with conditions such as coronary heart disease, chronic obstructive pulmonary disease (an umbrella term used for both chronic bronchitis and emphysema, which primarily affects longtime smokers), or diabetes, also require medical guidance.

Indeed, all people who have never stretched  before or are unsure of their technique-including those with no physical problems-should ask for expert help in designing a program tailored to their particular level of fitness.

If you are healthy, a certified personal trainer may suffice.  However, if you have any health concerns, see your doctor for advice and possible referral to a physical therapist or exercise physiologist (health professionals with special  training in exercise, joint motion, muscle strength, and endurance).

Proper technique is important because stretching incorrectly or when you shouldn't can do more harm than good.  Moving the wrong way can cause tiny tears in muscles and connective tissue, which may leave scar tissue after healing.  The scar tissue may then tighten the muscle, decreasing flexibility, and possibly increasing susceptibility to pain and injury.

The most important caveat is to warm up muscles before starting to stretch, because stretching without any preparation-while the muscles are cold-may cause injury.  "The only practical way to raise muscle temperature   is with aerobic exercise," Dr. deLateur says.

For people who work out regularly, she recommends 5 to 10 minutes of light aerobic exercise as a warm-up.  This is generally a slower or gentler version of the usual workout or a series of slow, rhythmic exercises that target larger muscle groups.  Riding a bicycle or walking work well.  The warm-up should be followed by gentle stretching, a full cardiovascular or strength training workout, and a final stretch.

"The last stretch is the one that does the most good, and the one that is too often neglected, because people are in a hurry,"  Dr. deLateur explains. This stretch is the best because muscle temperature is at its highest after the warm-up and a full workout, which reduces the potential for soreness and stiffness.

If stretching will be your only physical activity  for the day, warm up first by walking, pumping your arms, doing light calisthenics or performing another low intensity cardiovascular activity for 10 to 15 minutes.  Then do 10 to 15 minutes of stretching.  If you are looking for a more structured program, consider yoga.  A  5,000-year-old physical and mental discipline involving moving and stretching from one posture into another, yoga provides strength and flexibility to the whole body while it relaxes and calms.         

The following safety principles apply to all types of static stretching programs.

• Stretch your entire body, from head to foot, in any order that feels right to you; the best strategy varies from person to person.  Focus on the body's major muscle groups, including calf, thigh, and hip muscles, lower and upper back muscles, neck, and shoulders.  Don't neglect the knees, feet, and ankles.  Keep your body properly aligned, as uncontrolled twisting or turning can lead to injury.

Incorporate a full range of motion-both side to side and front to back-where appropriate.

• Hold each pose at least 30 seconds. 

One 30-second stretch is more beneficial than two  15-second stretches.                                                  

• Don't Bounce.  Repeated brief stretches of a muscle can increase stiffness and susceptibility to pain and offer no benefit.  They simply result in a reflex contraction of the muscle, similar to how the leg bounces when a doctor taps your knee.

• Move slowly and gently.  Vigorous stretching or jerking into a stretch can put undue stress on the ligaments and tendons, tearing them or  reducing  joint stability.

• Breathe.  Holding your breath while you stretch,    can cause muscles to contract and blood pressure to rise.  Regular breathing will deepen the stretch.  Begin by exhaling and extending the muscle, breathe slowly and deeply while holding the stretch and inhale when returning to a relaxed position.      

•Don't lock your joints into place when you straighten them.  They should remain very slightly bent.

• When lying on your back, move one leg at a time.  Sudden movements with both legs can strain the muscles and ligaments of the lower back.

• Make sure it feels good.  If not, your technique is incorrect or you may have a medical problem.  Stop and check with your doctor before continuing. # Material from the April 2001, Johns Hopkins Medical Letter..