Improved Body Composition
Healthy body composition means that the body has a high proportion of fat-free mass and a relatively small proportion of fat. Strength training improves body composition by increasing muscle mass, thereby tipping the body composition ratio toward fat-free mass and away from fat.
Building muscle mass through strength training also helps with losing fat because metabolic rate is related to muscle mass: The greater your muscle mass, the higher your metabolic rate. A high metabolic rate means that a nutritionally sound diet coupled with regular exercise will not lead to an increase in body fat. Strength training can boost resting metabolic rate by up to 15%, depending on how hard you train. Resistance exercise also increases muscle temperature, which in turn slightly increases the rate at which you burn calories over the hours following a weight training session.
Enhanced Self-Image and Quality of Life
Strength training leads to an enhanced self-image in both men and women by providing stronger, firmer muscles and a toned, healthy-looking body. Women tend to lose inches, increase strength, and develop greater muscle definition. Men tend to build larger, stronger muscles. The larger muscles in men combine with high levels of the hormone testosterone for a strong tissue-building effect; see the box “Gender Differences in Muscular Strength.”
Improved Body Composition Photo Gallery
Because strength training involves measurable objectives (pounds lifted, repetitions accomplished), a person can easily recognize improved performance, leading to greater self-confidence and self-esteem. Strength training also improves quality of life by increasing energy, preventing injuries, and making daily activities easier and more enjoyable.
Improved Muscle and Bone Health with Aging
Research has shown that good muscular strength helps people live healthier lives. A lifelong program of regular strength training prevents muscle and nerve degeneration that can compromise the quality of life and increase the risk of hip fractures and other potentially life-threatening injuries.
In the general population, people begin to lose muscle mass after age 30, a condition called sarcopenia. At first they may notice that they cannot play sports as well as they could in high school. After more years of inactivity and strength loss, people may have trouble performing even the simple movements of daily life, such as walking up a flight of stairs or doing yard work. By age 75, about 25% of men and 75% of women cannot lift more than 10 pounds overhead. Although aging contributes to decreased strength, inactivity causes most of the loss. Poor strength makes it much more likely that a person will be injured during everyday activities.
Increased Longevity
Strength training helps you live longer. A number of studies have associated greater muscular strength with lower rates of death from all causes, including cancer and cardiovascular disease. A study of more than 9000 men showed that compared to men with the lowest levels of muscular strength, stronger men were 1.5 times less likely to die from all causes; 1.6 times less likely to die from cardiovascular disease; and 1.25 times less likely to die from cancer. The results were particularly striking in men age 60 and older with low levels of muscular strength, who were more than four times more likely to die from cancer than similar-age men with greater muscular strength.
