According to the Centers for Disease Control, approximately 90 percent of American adults are so sedentary they could almost be reclassified as statues (1). It should therefore come as no surprise that obesity has increased by almost 70 percent in the past 10 years (12% to 20%). Nearly 60 percent of all adults in this country are overweight, and the percentage of obese children has doubled since the 1980’s. In addition to higher risk for heart disease and various types of cancer, obesity raises the risk of diabetes 10 times for men and 20 times for women (2).
Unfortunately, being overweight is merely the tip of the iceberg when it comes to body composition concerns. Sedentary adults typically add 10 pounds of bodyweight every decade during the midlife years. However, this unfavorable weight change results from a 5-pound loss of muscle and a 15-pound gain in fat. In other words, what appears to be a 10-pound weight problem is actually a 20-pound body composition problem (3).
In addition to adversely affecting personal appearance and physical performance, the reduction in muscle tissue is largely responsible for metabolic slow-down. The 5-pound per decade muscle loss is closely associated with a 5-percent per decade decrease in resting metabolic rate (4).
Even people who don’t increase their food intake experience creeping obesity, because calories previously used to maintain more muscle tissue are now placed in fat storage areas of the body.
Most Americans know that they are adding fat, but few realize that they are losing muscle. What’s more, they don’t understand that muscle loss is a major factor in fat gain. If they did, they wouldn’t place such a strong emphasis on dieting. With one out of every two adults presently following a low-calorie diet plan, we need a major teaching effort from health and fitness professionals to remedy this situation.
Although dieting can reduce fat, it cannot replace muscle to solve the primary body composition problem. In fact, low-calorie diets actually result in muscle loss, which accounts for approximately 25 percent of the total weight lost (5).
Fortunately, more overweight adults are complementing their diet plan with aerobic activity (usually walking) that burns additional calories and enhances cardiovascular fitness. While this combined program of diet and endurance exercise attenuates muscle loss, it does not add muscle or increase resting metabolic rate.
The missing component, of course, is strength training which does replace muscle tissue and recharge resting metabolism. Studies show that 25 minutes of standard strength training, two or three days a week, can increase previously inactive adults’ muscle mass by about three pounds in two to three months of training (6,7,8,9). What’s more, research reveals that three pounds of new muscle tissue increases resting metabolism by 6 to 8 percent, which represents an additional 100 to 120 calories per day (8,9).
Health Benefits of Strength Training
Strength training is the best means for attaining and maintaining a desirable body composition, as well as for developing a high level of musculoskeletal fitness. However, there are many other health-related reasons for performing regular resistance exercise. Consider the following medical benefits associated with sensible strength training.
Reduced Risk of Osteoporosis
The effects of progressive resistance exercise are similar for muscle tissue and bone tissue. The same training stimulus that increases myoproteins in muscle increases collagen proteins in bone. Researchers have reported significant bone mineral density development in older men (10) and women (11) who participated in standard strength training programs.
Reduced Risk of Type II Diabetes
One of the fastest growing health problems in the United States is diabetes, which presently affects 15 million American adults (2). Type II diabetes begins with a deficient glucose metabolism, which hinders the transfer of glucose from the blood to the muscles. Researches at the University of Maryland found that four months of regular strength training increased glucose uptake by almost 25 percent in the pre-diabetic study subjects (12). Their improved glucose metabolism improved the participants’ potential for avoiding type II diabetes.
Reduced Risk of Colon Cancer
Another University of Maryland study examined the effects of strength exercise on the transit time for food to pass through the gastrointestinal system (13). After just three months, the resistance trained subjects showed a 56 percent faster transit speed. This is a significant finding, because faster gastrointestinal transit time is associated with lower risk for colon cancer.
Reduced Rick of Cardiovascular Disease
Cardiovascular disease is the leading cause of death in the United States, and two primary predisposing factors are high blood pressure and high blood cholesterol. Contrary to popular misconception, properly performed strength exercise leads to lower resting blood pressure readings (6,14). In a study with almost 800 subjects, resting blood pressure was reduced about 4 mm Hg systolic and 3 mm Hg diastolic after just two months of combined strength and endurance exercise (7).
Likewise, researchers have found favorable effects on blood lipid profiles after several weeks of strength training (15,16). In fact, comparative studies have shown as much improvement in blood lipid profiles resulting from strength training as from endurance exercise.
Reduced Risk of Low Back Pain
As you are probably aware, about 80 percent of all Americans will experience low back pain during their lifetime. Fifteen years of research conducted at the University of Florida Medical School has indicated that the largest percentage of low back problems are related to weak low back muscles. Their studies have featured full-range strength exercise for the lumbar spine muscles, and the majority of their subjects have been pain-free or significantly improved after an average 10 weeks of training (15).
Reduced Risk of Depression
A recent study conducted at Harvard University placed clinically depressed seniors into one of two treatment groups (16). One group received educational counseling, while the other group performed three strength training sessions a week with no other intervention. The seniors who did strength exercise experienced significantly better results, with over 80 percent no longer meeting the criteria for depression after only 10 weeks of training.
Teach to Reach
Most adults and seniors are unfamiliar with strength exercise and uninformed regarding the health/wellness benefits of resistance training. They typically associate strength
training with bodybuilders and football players, and see no practical application to their own lives. However, when they understand the many ways in which strength exercise can enhance their personal health, increase their physical fitness, improve their overall appearance and reduce their risk of degenerative diseases, they are more likely to become strength program participants.
We use every means we can to present strength training information to the people (young and old) in our communities. These include television shows, radio spots, newspaper articles and local presentations (service clubs, senior centers, church groups, etc.). Getting the word out is the first step towards getting the people in, and the benefits of sensible strength exercise apply to just about everyone.