Another Pro Football season is over–concluding this year with a very lopsided Super Bowl victory. And, though the game wasn’t keeping us on the edge of our seats with suspense, we did witness some pretty incredible running and displays of strength. People exercise for many reasons. In the case of Pro Football players, it’s for the millions of dollars each of them gets yearly and a chance to own a $5,000 Super Bowl Ring. But, in your case, it might be because you know exercise makes you feel better, and benefits your heart, lungs, bones, and emotional stability. If weight loss and/or weight maintenance specifically are prime motivators for your exercise, there are some fundamentals which will assist you in these goals.
Research consistently confirms that regular physical activity, combined with healthful eating habits, is the most efficient and healthful way to control weight. All foods and most beverages contain calories; everything we do–including sleeping, breathing, and digesting food uses calories. Obviously the balance between calories IN and Calories BURNED is the ultimate regulator of our body weight. Excess calories are generally stored as body fat, and appropriate intentional physical activity will utilize these calories for energy rather than storing them in lovehandles, bellies, and thighs. And, it’s important to remember that all levels of physical activity–from running and intense aerobic dancing to housework and walking–will increase the number of calories our bodies use. The key to successful weight maintenance is making physical activity a part of our daily routines.
For the greatest OVERALL health benefits, experts recommend that we do 20 to 30 minutes of aerobic activity three or more times a week, as well as some type of muscle strengthening activity and stretching at least twice a week. If weight loss is the primary goal in your exercise regimen (at least initially), the frequency of your exercise should ideally be increased to 7 days/week with a duration of 45–60 minutes of exercise per session. Definitely, steady aerobic exercise lasting over 40 minutes per session is preferable to multiple short exercise sessions for fat-burning and weight loss. If you just said “Ye egads. . .there’s no way I could do that!!”. . . do you spend an hour per day watching television or just wasting time? If so, drag that exercise bike into the den or bedroom and watch the Today Show or your favorite sitcom while pedalling. Believe me, your ears and eyes still work while you’re exercising! Be creative; there really are 60 minutes in most of our days that could be committed to exercise of some kind.
Additionally, the ideal exercise or activity for losing weight is not one that leaves you “out of breath.” If you’re exercising aerobically and can still hold a conversation during the activity, you’re optimizing your body’s fat-burning. More strenuous exercise builds bigger muscles and burns a higher percentage of sugar in calories, but it’s not as efficient at whittling away the fat stores in our bodies.
Let’s talk about TARGET HEART RATE for a minute, and I think you’ll understand the zone for optimal weight loss better. There are several formulas to determine your target heart rate, but I think the easiest one is: Subtract your age in years from 220 to get your Maximum Heart Rate. This number is then multiplied by the Intensity Level of Exercise to get a Target Heart Rate. For example, a 50 year old physician exercising at 60% maximum heart rate would use the following formula: 220-50=170 (maximum heart rate). 170 x 60% = 102 beats/minute. Physical activity at 60–70% of the maximum heart rate can generally be continued safely for a long period of time–regardless of the type of physical activity. At 60% maximum heart rate, most people can comfortably converse during exercise (and, yes, even talking to yourself counts!). For beginners and/or people trying to make a renewed commitment to exercise, exercising at 50–60% of maximum heart rate is a good place to start. In this range, about 3 to 7 calories are burned per minute. At the next level of exercise, one aims for 60–75% level of maximum heart rate. 7 to 12 calories are burned per minute in this range. This is the PERFECT FAT BURNING ZONE, because 85% of the calories burned in this zone are fat. So, for weight loss, the longer one exercises in this zone, the more fat is burned and the more pounds are lost.
When one moves on up into zones 3, 4, and 5 of exercise intensity, fat is less of a percentage of the total calories burned. In fact, at the highest levels of exercise, anaerobic metabolism occurs in muscles, and there’s not enough oxygen around in the tissues to burn fat. Athletes target the highest levels of exercise to fine tune performance. But, if you’re simply hoping to squeeze into last year’s bathing suit this summer without horrifying yourself or strangers, exercising at 70% of your maximum heart rate is an ideal target zone.
Remember, too, that although the calorie expenditure during the exercise itself may appear disheartening to you overachiever babyboomers (e.g. 720 calories for 60 minutes of 70% maximum heart rate exercise for a 50 year old), our basal metabolism is increased by physical activity as well. So, the number of calories our bodies burn when we’re at rest increases by about 10% because we exercise, and this increase probably lasts as long as 48 hours after completing an activity. You can see how such a stimulation would be cumulative and beneficial in both weight loss and in long term weight maintenance.
Statistics show that 33% of U.S. adults are obese (defined as more than 20% overweight). Just wander through Target or your local airport, and you’ll verify this observation personally. But, if you make the commitment, and take the time to exercise correctly, you can avoid being ‘just another statistic’. And simultaneously, you’ll accrue a host of additional health benefits when you get the lead out.
Stephen L. Hines, M.D.
January 2001
