Watch the fine print when it comes to your health
By Karen Massey, edmondHEALTH
Q: I’ve had it!
No wonder people don’t pay attention to health reports! Thirty minutes of exercise used to be enough. Now it’s an hour. I’ve even heard that we should be exercising 90 minutes a day? What gives? Working out and eating celery 24/7 won’t pay the mortgage. Doesn’t a half-hour help? I admit it. I’m frustrated. Do you think they’ve gone too far? Do middle-aged women really have to exercise an hour a day to prevent weight gain?
A: I suspect you are referring to a recent article in the March issue of the Journal of the American Medical Association.
This article did seem to rankle a lot of attention! Indeed, headlines captured by health-cast reporters were pretty dramatic: “Middle-aged women must exercise an hour a day to fend off flab.” As with most scientific findings, it’s probably best to take a few minutes to sift through the original article before throwing your arms up in despair. It was true that women who were normal weight to begin with did maintain their normal weight if they did an hour of moderate activity a day.
However, it is also true that this study primarily focused on the exercise “side” of the energy equation. Remember, weight control is a combination of food intake and exercise expenditure. Readers should immediately appreciate that food intake is equally important when it comes to weight control. In this study, participants were not necessarily restricting their food intake. Knowing that is a relief. Most middle-aged women, who are interested in weight control, intuitively grasp that food matters!
While food intake was assessed at “baseline” in the study, food intake was never reassessed. Off-hand, I’d question that middle-age women might be likely to make changes in their diets (wittingly or unwittingly) over a 13-year period of time.
Another potentially confounding factor, if/when attempting to “compare” this information to “real life,” is that the women in the study, who maintained their weight, weighed less than then average American woman does. The average American woman stands 5-feet, 3.8-inches tall and weighs 164.7 pounds. However, the mean weight of the women in the subgroup (who avoided weight gain by exercising one hour a day) only weighed 145.6 pounds. Isn’t it possible that the average American women, being almost 20 pounds heavier, might find it more difficult to exercise for an hour everyday?
It’s not particularly amazing that smaller women would have to exercise harder or longer than larger women to maintain their weight. This would be expected since smaller women burn fewer calories for the same amount of exercise. Plus, they have smaller energy (calorie) needs in the first place. In other words, their “calorie budget” is more limited. Therefore, smaller women may resort to exercising more since they don’t have as many calories to “cut” from their food intake.
The heavier participants in the study also had more health problems (high blood pressure, diabetes) as well as a slightly higher percentage of women who smoked and ate fewer servings of fruits and vegetables than the “hour-exercisers” did.
This too, is not uncommon in the literature. Health habits tend to occur in “clusters.” People who eat fruits and vegetables tend to be the same people who exercise, don’t smoke, wear their seatbelts and generally engage in healthy behaviors, which may have a synergistic effect.
Relax! As you can see, nutrition research is quite complicated. It takes years of investigating before concrete recommendations can be made. This study was intriguing because it had so many participants. Still, at least in my mind, it left many unanswered questions.
Weight control is a complex combination of food intake and expenditure. Don’t let this study derail your exercise program! Yes, a half-hour is worthwhile! Does it really take an hour a day to maintain weight? Maybe, maybe not. Either way, physical exercise has so many additional benefits! Even if a lady does gain a few pounds as she ages, she’s going to be better off if she engages in regular exercise.
So, grab what you have time for. If it’s an hour, that’s great. However, a half-hour (or even 15 minutes) has perks too. Don’t fall into the “all-or-nothing” trap. Anything beats sitting around!