GENERAL EXERCISE BENEFITS
Regular physical activity postpones death, mostly by its effect on cancer, strokes, and heart attacks.
Exercise is a fountain of youth. Peak aerobic power (or fitness) naturally diminishes by 50 percent between young adulthood and age 65. Regular exercise increases fitness (aerobic power) by 15–20 percent in middle-aged and older men and women, the equivalent of a 10–20 year reduction in biological age.
Additional benefits of exercise include: 1) enhanced immune function, 2) stronger bones, 3) preservation and improvement of flexibility, 4) lower blood pressure by 8–10 points, 5) diminished premenstrual bloating, breast tenderness, and mood changes, 6) reduced incidence of dementia, 7) less trouble with constipation, 7) better ability to handle stress, 8) less trouble with insomnia, 9) improved self-esteem, 10) enhanced sense of well-being, with less anxiety and depression, 11) higher perceived level of energy, and 12) prevention of weight regain.
EFFECT ON DIABETES
Eighty-five percent of type 2 diabetics are overweight or obese. It’s not just a random association. Obesity contributes heavily to most cases of type 2 diabetes, particularly in those predisposed by heredity. Insulin is the key that allows bloodstream sugar (glucose) into cells for utilization as energy, thus keeping blood sugar from reaching dangerously high levels. Overweight bodies produce plenty of insulin, often more than average. The problem in overweight diabetics is that the cells are no longer sensitive to insulin’s effect. Weight loss and exercise independently return insulin sensitivity towards normal. Many diabetics can improve their condition through sensible exercise and weight management.
Muscles doing prolonged exercise soak up sugar from the blood stream to use as an energy source, a process occurring independent of insulin’s effect. On the other hand, be aware that blood sugar may rise early in the course of an exercise session.
You don’t have to run marathons (26.2 miles) or compete in the Ironman Triathlon to earn the health benefits of exercise. However, if health promotion and disease prevention are your goals, plan on a lifetime commitment to regular physical activity.
For the general public, the U.S. Centers for Disease Control and Prevention recommends:
- at least 150 minutes per week of moderate-intensity aerobic activity (e.g., brisk walking) and muscle-strengthening activity at least twice a week, OR
- 75 minutes per week of vigorous-intensity aerobic activity (e.g., running or jogging) plus muscle-strengthening activity at least twice a week. The muscle-strengthening activity should work all the major muscle groups: legs, hips, back, abdomen, chest, shoulders, arms.
I’m working on a program of combined aerobic (high intensity interval training) and strength training for just 70 minutes a week, but it’s not yet ready for prime time.
What’s “strength training”? It’s also called muscle-strengthening activity, resistance training, weight training, and resistance exercise. Examples include lifting weights, work with resistance bands, digging, shoveling, yoga, push-ups, chin-ups, and other exercises that use your body weight or other loads for resistance.
Strength training just twice a week increases your strength and endurance, allows you to sculpt your body to an extent, and counteracts the loss of lean body mass (muscle) so often seen during efforts to lose excess weight. It also helps maintain your functional abilities as you age. For example, it’s a major chore for many 80-year-olds to climb a flight of stairs, carry in a bag of groceries from the car, or vacuum a house. Strength training helps maintain these abilities that youngsters take for granted.
According to the U.S. Centers for Disease Control and Prevention: “To gain health benefits, muscle-strengthening activities need to be done to the point where it’s hard for you to do another repetition without help. A repetition is one complete movement of an activity, like lifting a weight or doing a sit-up. Try to do 8–12 repetitions per activity that count as 1 set. Try to do at least 1 set of muscle-strengthening activities, but to gain even more benefits, do 2 or 3 sets.”
If this is starting to sound like Greek to you, consider instruction by a personal trainer at a local gym or health club. That’s a good investment for anyone unfamiliar with strength training, in view of its great benefits and the potential harm or waste of time from doing it wrong. Alternatives to a personal trainer would be help from an experienced friend or instructional DVD. If you’re determined to go it alone, Internet resources may help, but be careful. Consider “Growing Stronger: Strength Training for Older Adults” (ignore “older” if it doesn’t apply).
Current strength training techniques are much different than what you remember from high school 30 years ago—modern methods are better. Some of the latest research suggests that strength training may be even more beneficial than aerobic exercise.
“Aerobic activity” is just about anything that mostly makes you huff and puff. In other words, get short of breath to some degree. It’s also called “cardio.” Examples are brisk walking, swimming, golf (pulling a cart or carrying clubs), lawn work, painting, home repair, racket sports and table tennis, house cleaning, leisurely canoeing, jogging, bicycling, jumping rope, and skiing. The possibilities are endless. A leisurely stroll in the shopping mall doesn’t qualify, unless that makes you short of breath. Don’t laugh: that is a workout for many who are obese.
But which aerobic physical activity is best? Glad you asked!
Ideally, it’s an activity that’s pleasant for you. If not outright fun, it should be often enjoyable and always tolerable. Unless you agree with Ken Hutchins that exercise isn’t necessarily fun.
Your exercise of choice should also be available year-round, affordable, safe, and utilize large muscle groups. The greater mass and number of muscles used, the more calories you will burn, which is important if you’re trying to lose weight or prevent gain or regain. (Exercise isn’t a great route to weight loss in the real world, although it helps on TV’s Biggest Loser show.) Compare tennis playing with sitting in a chair squeezing a tennis ball repetitively. The tennis player burns calories much faster. Your largest muscles are in your legs, so consider walking, biking, many team sports, ski machines, jogging, treadmill, swimming, water aerobics, stationary cycling, stair-steppers, tennis, volleyball, roller-skating, rowing, jumping rope, and yard work.
Walking is “just what the doctor ordered” for many people. It’s readily available, affordable, usually safe, and requires little instruction. If it’s too hot, too cold, or rainy outside, you can do it in a mall, gymnasium, or health club.
All I’m asking you to do is aerobic activity, such as walk briskly (3–4 mph or 4.8–6.4 km/h) for 30 minutes most days of the week, and do some muscle-strengthening exercises three times a week. These recommendations are also consistent with the American Diabetes Association’s Standards of Care–2013. This amount of exercise will get you most of the documented health benefits.
Steve Parker, M.D.