As an assistant professor at the University of Washington, Glen Duncan teaches an epidemiology class that explores the relationship between disease and physical activity. His course, the only one at UW on the subject of how physical activity or lack of it affects personal health, is populated with both undergraduates and grad students.
"The grad students are mostly public health majors and the undergrads tend to be pre-med," said Duncan the other morning.
In sum, Duncan is teaching young people who aspire to have jobs that take on such highly challenging issues as the obesity crisis and reversing heart disease. He regularly discusses the hot debate among researchers about whether you can be "fat but still fit." A new Harvard study cast doubt on the concept just last week in the pages of the journal Annals of Internal Medicine.
Identifying healthy body weight is another topic in Duncan's class. In April, Mayo Clinic researchers presented a new paper at a major cardiology meeting suggesting that people with healthy weight but high body fat percentage might be better categorized as "normal weight obese." The body fat numbers: greater than 20 percent for men and greater than 30 percent for women.
Duncan said his students have a hard time understanding all of the fuss.
"Lots of these students are very fit and active," Duncan said. "When I explain that a significant part of the American population can't climb a flight of stairs without being out of breath, they don't believe it at first. They say things like, 'Do you actually mean that? Is that really true? Whoa!' "
Whoa is right. Seeking a solution to America's obesity crisis is almost too overwhelming, even for Duncan. Same goes for figuring what exactly is an ideal or healthy body weight.
"I used to be one of those researchers who design a clinical trial with a group of overweight people, give them an exercise prescription and track the outcome," said Duncan, whose current scientific investigations focus on how environment such as a walkable neighborhood ("think Capitol Hill") can positively affect health. "Now I urge people to get off the couch. That's my exercise prescription. Less butt time."
As for determining ideal weight, Duncan called it the "million-dollar question" and said it is pretty much impossible to name a precise number of pounds by, say, height or age or whether someone has proverbial big bones.
"There is too much stress on weight," said Duncan. "It's better to focus on getting healthy. You can be healthy at a higher weight (than what a professional might consider ideal), though I will never be one to say there aren't negative effects of obesity."
Here's a common scenario to illustrate overstressing weight: The well-meaning personal trainer at the health club does a fitness assessment and tells a new member she needs to lose 30 pounds.
That member has three choices: 1. Do nothing because losing 30 pounds won't happen; 2. Practically starve or exhaust herself to hit the 30 pounds; or 3. Decide for herself what is an ideal weight, given she does want to shed some pounds but nowhere near the 30.
Duncan votes for No. 3.
"Fixating on (losing the 30 pounds) leads to a crash diet," he said. "People commit to those crash diets, lose the weight, then realize there is no way they can eat that way for the rest of their lives. They gain the weight back."
In fact, research shows people not only regain the original weight but additional pounds on top of it.
Duncan identified some basic markers to gauge personal health: climbing a flight of stairs without struggling for breath; the ability to take a 30-minute walk; cutting way back on TV; and "not eating so much at any one meal."
If you can do these things, you could be in range of a healthy weight. Getting to an ideal weight is more about adding intensity to workouts that fretting over the government's Body Mass Index calculation or the bathroom scale.
"There are three parts to effective workouts or physical activity: frequency, intensity and duration," Duncan said. "Intensity is the most direct way to change your health for the better (and likely lose body fat in the process)."
If you are a runner, devote the last 10 to 15 minutes of some runs to hard sprinting for 30 seconds followed by 90 seconds of recovery pace, then repeat three to five times. If you walk for exercise, do the same 30-second burst/90-second recovery pace sequence or add some hills (or incline on your treadmill). For weight lifters, load your barbell at an amount that fatigues the muscles after 8 to 12 repetitions.
"I recommend increasing your intensity because it fits into life," said Duncan. "Take my students. They don't see themselves 10 years from now, when jobs and families might make it harder to work out and keep the weight off. I am hoping to get them to see the big picture."
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