By Wayne L. Westcott, Ph.D.

    Wayne L. Westcott, Ph.D., is fitness research director at the South Shore YMCA in Quincy, Massachusetts, and author of the college textbook Strength Fitness: Physiological Principles and Training Techniques.

   During the past few years, research has continued to show that sensible strength training produces many health and fitness benefits. The exciting news is that in addition to confirming the positive physiological responses already discovered, key researchers have pinpointed other benefits.

    To reap all these benefits (listed below), ask your personal fitness trainer or instructor to help you design a safe, effective strength training program.

Researchers have discovered that strength training provides these benefits:

Low-back Pain Decreases. Several years of research on strength training and back pain conducted at the University of Florida have shown that strong low-back muscles are less prone to injury. A recent study by Risch (1993) found that low-back patients had significantly less back pain after 10 weeks of specific (full-range) strength exercise for the lumbar spine muscles.

Arthritic Pain Decreases. According to the Tufts University Diet and Nutrition Letter (September 1994), sensible strength training may ease the pain of osteoarthritis and rheumatoid arthritis. This is good news, because most men and women who suffer from arthritis need strength exercise to develop stronger muscles, bones and connective tissue. (If you have arthritis, strength training could be a big help. Be sure to check with your doctor before beginning a program.)

Resting Blood Pressure Decreases. Harris and Holly (1987) showed that regular strength training alone significantly reduces resting blood pressure. Westcott (1995) revealed that a combination of strength training and aerobic exercise improves blood pressure readings even more. After two months of combined exercise, program participants dropped their systolic blood pressure by five millimeters of mercury (mm Hg) and their diastolic blood pressure by 3 mm Hg.

Bone Mineral Density Increases. Menkes (1993) reported significant increases in the bone mineral density of the upper femur after four months of strength exercise.

Glucose Metabolism Improves. Hurley (1994) reported a 23 percent increase in glucose uptake after four months of strength training. Because poor glucose metabolism is associated with an increased risk of adult onset diabetes, improved glucose metabolism is an important benefit.

Gastrointestinal Transit Time Decreases. A study by Koffler (1992) showed a 56 percent decrease in gastrointestinal transit time after three months of strength training. This finding is significant because delayed gastrointestinal transit time is related to a higher risk of colon cancer.

Blood Lipid Levels Improve. Although strength training’s effect on blood lipid levels needs further research, at least two studies (Stone et al. 1982; Hurley et al. 1988) have revealed improved blood lipid profiles after several weeks of strength exercise.

Although endurance exercise improves cardiovascular fitness, it does not prevent muscle tissue loss. Only strength exercise maintains muscle mass and strength throughout midlife.

• Campbell and his coworkers (1994) found that a three-month basic strength training program resulted in subjects gaining three pounds of muscle and losing four pounds of fat, while eating 370 more calories per day (a 15 percent calorie increase).

• Westcott (1995) showed that a standard strength training program can increase muscle mass by about three pounds over an eight-week training period. This is the typical training response for men and women who do 25 minutes of strength exercise three days per week.

• Research reveals that adding three pounds of muscle increases resting metabolic rate by up to 7 percent and daily caloric requirements by up to 15 percent (Campbell et al. 1994). At rest, a pound of muscle requires up to 35 calories per day for tissue maintenance; during exercise, use of muscle energy increases dramatically. Adults who add muscle through sensible strength exercise use more calories all day long, so are less likely to accumulate fat.