Yesterday's Wall Street Journal contained two articles on the benefits of exercise, just in time for the legions of people whose New Year's resolutions include beginning an exercise routine. One article, "The Hidden Benefits of Exercise" by Laura Landro, mentions how exercise plays a role in fighting off a variety of ailments, from the common cold to cancer to depression to Alzheimer's. This is nothing new to anyone who exercises. "No pill or nutritional supplement has the power of near-daily moderate activity in lowering the number of sick days people take," says one researcher in the article.
The Department of Health and Human Services recommends that adults get at least two hours and thirty minutes weekly of moderate-intensity aerobic physical activity, or one hour and fifteen minutes a week of vigorous intensity aerobic exercise, or an equivalent combination of both (see here for the government's guidelines). According to Landro, you can meet the moderate-intensity guidelines by merely walking briskly for 30-45 minutes five times a week.
Dr. Paul Williams has a problem with this, according to the other article "And Why More May Even Be Better" by Kevin Helliker. Williams studied 100,000 runners over 20 years and found that increasing your exercise intensity leads to even greater health benefits. "Exceeding the federally recommended guidelines can reduce the risk of stroke, heart attack, glaucoma, diabetes, and other diseases by as much as 70% above the benefits of merely exceeding the guidelines," Helliker writes. The problem is that many of Williams's colleagues don't want to hear this. They exclude Williams from guideline-formulating committees and reject many of his grant proposals because they don't want to hear the idea that more is better.
Williams's colleagues, including those in the government, don't want to scare sedentary people away by telling them that they may have to lose their breath and experience some measure of discomfort if they really want to reap the benefits of exercise. With 50% of this country's population sitting on the couch eating Cheetos and watching Law and Order reruns, researchers want to coax this group with baby steps instead of a daunting mandate whose subtext is that exercise, to be effective, might make them uncomfortable.
Dr. Williams found increasingly stronger benefits for runners as they increased mileage, up to 50 miles per week. As a result, he wants the government to create a two-tiered approach to the guidelines, with one tier for those who far surpass the minimum guidelines. From the article, some support for increased mileage:
A 2008 article published in Medicine & Science in Sports & Exercise found that men and women who ran long distances over a period of eight years substantially reduced their odds of developing diabetes. Conversely, however, a 2007 Runners' Health study published in the journal Diabetes Care found that runners who cut back on their mileage had a greater risk of diabetes than those who maintained their exercise levels.
A Runners' Health study published in the journal Stroke last spring found that men and women who ran more than eight kilometers a day had a 60% lower risk of stroke than those who ran at the guideline levels. An article published in September in the journal Atherosclerosis found that those Runners' Health participants who exceeded guideline levels had a 26% lower risk of coronary heart disease than those who ran at guideline levels.
I understand the government's reasoning. It's hard enough to get people to start and maintain an exercise routine. Doctors don't want to scare people off with the idea that if you really want to benefit, you'll have to suffer a bit. But it sounds like this is where the "no pain, no gain" mantra really is true.
And I have a hard time believing that the guy walking briskly for 30 minutes is getting the same benefit as I am when I run 30 minutes at a 6:30 pace. Even better, I have a really hard time believing that gardening--an example of "moderate" activity, according to the government--bestows the same effect as brisk walking or biking on a flat surface, both also considered moderate activity. Sure, gardening outside your home five times a week is better than watching the Home and Garden network five days a week, but my own gut instinct is that we should be telling people to do more than just pull shrubs. It's better than doing absolutely nothing, but we won't see a study anytime soon with the finding that gardening reduces your risk of coronary disease.
I also take issue with one passage from Helliker, from both an exercise and a rhetoric standpoint. Here's the passage, referencing Dr. Paul Thompson:
Yet as chief of cardiology at Hartford Hospital in Connecticut, Dr. Thompson notes that vigorous exercise regimens can lead to injury. And he also observes in many patients a fragile motivation to exercise. Among those currently meeting or slightly exceeding the guidelines, a daunting new challenge might prove discouraging, he says. "And if you make them run more and they get injured, then they wind up running less."
To be sure, I am a PhD, not an MD, so I will not pretend to be versed in anatomy and physiology. But the first sentence throws me off with a weak transition. The phrase "Yet as chief of cardiology at Hartford Hospital" can also be read as "Because of his experience as chief of cardiology at Hartford Hospital." And this is not really true; Thompson is a cardiologist, not an orthopedist, so the "Yet as" opener isn't really appropriate.
Helliker also tells us that "vigorous exercise regimens can lead to injury." Can is the key word here. People don't get injured simply because they start exercising more. Instead, they get injured for a host of reasons: poor running form, unfriendly running surfaces, bad shoes, not enough recovery time between workouts, too much too soon, among other reasons. Injury is not a logical outcome of vigorous exercise, but it is often the logical outcome of bad exercise. So I don't want people getting the idea that upping one's mileage will automatically lead to stress fractures.
The print edition of the WSJ, by the way, satisfies both walkers and runners with one of the photos accompanying the article: a group of race walkers. I don't know if the editors even knew that the people in the picture were race walkers, but it's obvious from their stride.
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