Since Dr. Kenneth Cooper published his first Aerobics book in 1968, there has been a major emphasis on physical fitness in the United States. We have experienced the running revolution of the 1970s, the aerobic dance movement of the 1980s, and the strength training interest of the 1990s. Today, most people are aware that exercise is good for their health, and is in fact an effective means of preventive medicine.
It is therefore hard to understand why so few people regularly participate in an exercise program. According to the United States Public Health Service Centers For Disease Control (1989), less than 10 percent of all Americans perform enough physical activity to attain any measurable fitness benefits. Most of those who do exercise consistently are walkers and joggers, leaving less than five percent of the general public who do strength training.
Strength Training Misconceptions
Some of those who avoid strength exercise do so because they have heard that it may increase their blood pressure. Fortunately, this is not true. Although every adult should have physician approval before starting a strength program, research reveals that properly-performed strength exercise is similar to aerobic activity in terms of blood pressure response (Westcott 1983, 1985, 1987). That is, systolic pressure increases about 35 to 50 percent during exercise and returns quickly to resting levels after the activity session. More important, studies show that several weeks of strength training result in significant reductions in resting blood pressure (Holly and Harris 1987; Westcott, 1995a). For example, 785 men and women who participated in a two-month program of strength and endurance exercise experienced an average 4 mm Hg decrease in systolic blood pressure and 3 mm Hg decrease in diastolic blood pressure (Westcott 1996). Sensible strength training, alone or in combination with endurance exercise, has beneficial effects on resting blood pressure.
Another reason many adults avoid strength exercise is the fear of increasing their bodyweight. They mistakenly believe that weight training is synonymous with weight gain. It is true that strength training adds muscle, but this is actually the best way to lose fat. In fact, strength exercise has a threefold impact on fat reduction. First, it increases calorie utilization during each training session. Second, it increases calorie use for several hours following exercise due to the afterburn effect (Melly 1993). Third, it increases calorie utilization all day long by adding new muscle tissue. This is because every pound of new muscle uses about 35 calories each day just for tissue maintenance (Campbell 1994).
A study of 1,132 adults revealed excellent body composition improvements after two months of strength and endurance exercise (Westcott 1996). As shown in Table 1, the men gained 3.7 pounds of muscle and lost 6.4 pounds of fat, and the women gained 1.7 pounds of muscle and lost 3.4 pounds of fat. Strength training, alone or in combination with endurance exercise, has beneficial effects on body composition.