Over the past 25 years, ever since the introduction of Dr. Kenneth Cooper’s book, Aerobics, many individuals have focused on walking, running, cycling and other types of aerobic activity as their only means of exercise. Unfortunately, this has led to many of us neglecting another key component of fitness – total body conditioning. Many of us lack the strength to carry a full bag of groceries up a flight of stairs. In addition, as we have aged, we have replaced muscle tissue with fat tissue.
Research by Dr. Gilbert Forbes, of the University of Rochester School of Medicine, shows that the average man loses about a half-pound of muscle per year after the age of 20. This average man is one who does not engage in total body conditioning. At the age of 50, his body weight is 15 pounds less muscular than at age 20. ”The more muscles you involve in an exercise program, the greater the demand placed on the heart, circulatory and musculoskeletal systems. And, of course, the greater the benefit from the exercise.
Total body conditioning can do more to ensure a long, healthy life than just about anything else known to the medical community today. It’s never too late to start a fitness program, but ideally, you should build strong muscles and a strong cardiovascular system and enter the later years with your physical potential at its maximum. The lean look of the runner or swimmer grew out of the aerobics boom of the 1970’s. Not only did ordinary people get caught up in the aerobics movement, but even the experts trumpeted the benefits of aerobic activity. There was an elitist view in the medical community of aerobic exercise versus strength training.
“Such thinking has come full circle – lean runners and other aerobicizers are still the majority of exercisers, but experts maintain that an either/or approach to conditioning is no longer in a person’s best interest. Today’s fitness conscious adult needs to do both aerobic and strengthening exercises.”
In keeping with this thinking, fitness authorities, such as the American College of Sports Medicine (ACSM), have recently amended their fitness recommendations, pointing out the need to add strength training to aerobic exercises. In 1978, the ACSM released fitness guidelines calling for three to five days a week of aerobic exercise for 20 to 60 minutes per session.
In their revised guidelines, the ACSM still recommends that we do aerobic exercise three to five sessions a week for 20 to 60 minutes. However, it says that “strength training of moderate intensity, sufficient to develop and maintain fat-free weight, should be an integral part of an adult fitness program. One set of eight to 12 repetitions of eight to 10 exercises that strengthen the major muscle groups, at least two days a week, is the recommended minimum.“
The primary reason we need to do resistance training is to build muscle and maintain muscular strength. As we grow older, we lose muscle which can lead to a host of functional disabilities ranging from lack of ability to carry out activities of daily living, to low back problems. Prevention of osteoporosis is another reason that women – and men – need to strength train. Research has shown that bone loss slows and bone density increases among individuals who participate in strength training programs and correct the diet.
The combination of resistance training with aerobic activities may be the best adjunct to a weight management program. Aerobic exercise is good for burning calories during the activity, but the more muscle mass you build (or maintain), the more calories you burn on a 24 hour basis. Fat cells are not very metabolically active, but muscle mass counts a lot, since muscle cells are metabolically active even when you are not exercising.
Your resting metabolic rate declines by about two percent every 10 years after the age of 20. This means that every 10 years, you need to eat about 100 fewer calories per day to maintain your body weight. Some decline is inevitable, but strength training and cardiovascular exercise may at least slow this process.
So where does all this leave us?
The bad news is that research verifies what we already know. As we age, we experience a gradual decline in endurance, physical capacity, muscular strength, muscular mass and metabolic rate. These changes increase our risk of cardiovascular disease and various degenerative disorders. The good news is that regardless of age or sex, with regular aerobic exercise and strength training, we can reverse these insidious processes and delay the effects of aging.
The research is in:
To guarantee overall fitness and health, you must maintain an exercise regimen that combines both aerobic and strength training activities. Considering the relatively low investment in time and the high dividends in physical fitness, we should all be participating regularly in appropriate levels of aerobic and strength training. The American College of Sports Medicine (ACSM) offers these guidelines for cardiovascular fitness: Three to five days a week for 20 to 60 minutes per session. Continuous aerobic exercise using large muscle groups such as walking, cycling, running, swimming, cross-country skiing and aerobic dance. The intensity of the exercise should reach 60 to 85 percent of maximum heart rate.
These are the ACSM guidelines for strength-training workouts:
Strength train at least twice but no more than three times per week PER BODYPART. Complete eight to 10 exercises that work all the major muscle groups. Complete at least one set of each exercise. Complete eight to 12 repetitions within each set while taking the muscles to near exhaustion.