The American College of Sports Medicine (ACSM) recommends that adults get an accumulated 30 to 45 minutes or more of simple physical activity (for example, walking the dog, taking the stairs rather than the elevator, etc.) most, if not all days of the week. For fitness benefits, according to the ACSM, adults should do 20 to 60 minutes of continuous aerobic activity, three to five days a week at 60 percent to 90 percent of their maximum heart rate using the major muscle groups (swimming and cycling are good ways to accomplish this).
Estimate your maximum heart rate by subtracting your age from 220. Multiply this number by 0.6 to find the lower heart rate number that you want to reach and maintain while exercising. Example: A 40-year-old would subtract 40 from 220 and get 180. Then multiply 180 by 0.6 to get 108. Our 40-year-old would then try to keep his or her heart rate at around 108 beats per minute while exercising. For most people, exercising longer at a heart rate of 60 to 70 percent of maximum is preferred over exercising for shorter durations at higher heart rates.
2. What's the best form of aerobic exercise?
Any form of steady exercise will be effective, in health terms, provided that it uses large muscle groups and can be sustained over time, preferably 30 to 45 minutes. Cross-country skiing and moderate-to-fast cycling are the most aerobically demanding sports, followed by running, swimming, aerobic dance and, finally, walking.
3. If I become fit doing one type of aerobic exercise, will this help prepare me for other forms of exercises?
Every type of aerobic exercise yields general improvements to your cardiovascular system, such as a stronger heart muscle and lower blood pressure. But improvements in endurance also come from training specific muscles. Becoming a fit runner, for example, won't improve the endurance of your swimming muscles as much as swimming will — to do that, you'll need to start swimming on a regular basis. Most studies show that the best way to be good at one sport is to practice that sport.
4. How does exercise help reduce body fat?
Exercise helps in a number of ways. First, it burns extra calories — a few hundred or more per hour of exercise, depending upon your weight and how hard you work out. Frequent exercise and moderate food intake can add up to a significant decrease in fat. (A pound of fat contains 3,500 calories.) Over time, an exercise program also raises your resting metabolism (by increasing your muscle mass), enhances your ability to burn the fats you eat (instead of converting them into fat that your body stores), and also can improve the appetite-control system in your brain (making you less prone to overeating).
5. Will using hand weights help me get a better walking workout?
Studies have shown that holding hand weights does nothing to increase the aerobic demands of a walking workout — and by throwing off your stride, they can raise the risk of a stress-related injury. If you choose to walk with weights, experts recommend using weights of a half-pound or less.
6. How important is it to warm up before exercising?
Because it takes a few minutes for your aerobic system to kick in fully, it's a good idea to begin each exercise session with a few minutes of very easy walking, swimming, etc., before reaching your normal pace. This way you'll avoid premature fatigue and increase your chances of a smooth, trouble-free workout. Some easy stretching is also fine, but anything more involved isn't necessary before aerobic exercise: Studies have found that lengthy warm-ups do not reduce the risk of injury.
7. Will lifting weights make me healthier?
For people younger than 50, strength training appears to boost HDL cholesterol levels (that's the good kind) modestly and also builds significantly more muscle mass than aerobic training — making fat loss easier. For people older than 50, strength training may be even more important, because we all gradually lose muscle mass as we age. Lifting weights two to three times a week can prevent or slow this decline. In addition, lifting weights and performing weight-bearing exercise puts stress on bones, which respond by getting stronger, reducing the chances of osteoporosis.
8. If I start a running program, do I risk getting arthritis in my hips, knees or ankles later on?
Contrary to popular belief, researchers have found that arthritis is not more common in long-time runners than other people. Normal joints can take millions of repetitive, stressful motions. However, abnormal joints (those with arthritis or cartilage damage) can be worsened by certain exercises. If you have joint problems you should consult your physician (or a specialist in exercise) before you add running to your fitness routine.
9. Is it true that the fitter I get, the healthier I'll be?
Not necessarily. Being in good shape can make you healthier, but to push beyond your limits can be unhealthy. The heavy training needed to become a world-class endurance athlete (often several hours a day of intense exercise) doesn't offer any extra health benefits, and it carries an increased risk of injuries and other stress-related illnesses.
10. What's the best sports diet?
There is no definitive recommendation. Traditionally, sports diets have emphasized complex carbohydrates, found in fruits, vegetables, cereals and grains, pasta and beans. But more recent research suggests that a more balanced approach with moderate protein and healthy fats may be equally beneficial. Fats and protein take longer to digest, so allow more time after meals before working out or competing. And remember to drink plenty of fluids.