Exercise, Blood Lipids and the Media
Frederick C. Hatfield II, MS, MFS, CSCS
Recently science has linked exercise to improved cholesterol levels. That’s great news and worthy of mention. However, there is a bigger story behind this. It’s not what the science says, but how it was interpreted and reported that has perked my ears.
Before we begin, let’s look at the abstract, which is from the November 7th, 2002 edition of the New England Journal of Medicine.
The abstract notes several points:
- Physical activity is related to reduced cardiovascular disease, but
researches weren’t sure if improved lipoprotein profile was a reason.
- The researchers wanted to know if the amount, intensity or both were involved in the improvement of lipoprotein in the blood system. Basically, they wanted to know if whether improved cholesterol levels were a matter of duration, intensity or both.
- They studied overweight men and women. They studied 3 groups. They defined each group based on caloric expenditure to define intensity levels.
- Those that engaged in “high intensity” exercise (which was defined as the caloric equivalent of jogging 20 miles a week at 65-80% of Max VO2) had the best results.
- Subjects who exercised at lower levels still had a better profile over those who didn’t exercise at all.
So the bottom line is that harder training yielded the best results, but even a little exercise was better than none. The final conclusion of this study is noted in the abstract:
The highest amount of weekly exercise, with minimal weight change, had widespread beneficial effects on the lipoprotein profile. The improvements were related to the amount of activity and not to the intensity of exercise or improvement in fitness.
The study is screwy in so many ways. But that is not the point of this story. The point is how it was reported. So, now that you know what was said in the original story, lets have a look at some headlines and newspaper quotes.
“Exercise linked to improved cholesterol”
Andre Picard, who’s a public health reporter notes:
“Regular physical activity can improve a person’s cholesterol markedly, even if they don’t lose weight or improve their fitness level in the process, according to a landmark U.S. study.”
Fitness levels don’t need to improve and weight loss (fat loss) doesn’t need to happen for cholesterol levels to improve.
“Any exercise benefits body.”
November 7, 2002. An exercise programme can do your heart good even if you don’t lose weight, says a new study that used advanced methods to take a close look at blood cholesterol levels.
The exercise doesn’t have to be all that strenuous to reduce your risk of heart trouble, says Dr William Kraus, an associate professor of medicine at Duke University Medical Centre and leader of a group reporting the findings in the November 6 issue of The New England Journal of Medicine.
“Some exercise better than none.”
The participants were divided into four groups. One was assigned to vigorous exercise, the caloric equivalent of 32km of jogging a week, a second to the equivalent of 19km of jogging a week, a third to the equivalent of 19km of brisk walking, and the fourth to doing nothing in particular.
“One major point is that the inactive folks deteriorated at a rate faster than we would have predicted,” Kraus says. “They gained an average of 1.4kg in six months, and their cholesterol levels also deteriorated.”
“A second finding was that anyone assigned to an exercise group did better. Even a low amount of exercise prevented that deterioration. Some exercise is better than none, and more is better than less,” he says.
“Third, we found that one need not focus on weight change. Even in the absence of significant weight loss, people got a benefit from being in an exercise group,” he adds.”
This is from HealthScoutnews. Exercise doesn’t have to be strenuous and you don’t have to lose weight. Furthermore, even though it is noted more exercise is better, the reporter notes, “some exercise is better than none”.
The Discovery Channel’s website has a different opinion. Somewhat…
“More Exercise is Better for the Heart”
AFP (Discovery channel website)
Nov. 6 – The more a person exercises the greater the benefit to cardiovascular health, a study published Wednesday found, drawing a direct link between the amount of regular exercise and the reduction of harmful cholesterol.
The study published in the New England Journal of Medicine is the latest to link exercise and a reduced risk of heart disease. Its authors said it was also a powerful warning of the dangers of obesity and a sedentary lifestyle.”
Now, we learn that more exercise is better and obesity as well as sedentary lifestyle is a powerful warning.
“Duration, not intensity, of exercise key to lower cholesterol”
By Steve Sternberg, USA TODAY
RALEIGH, NC — (INTERNET WIRE) — 11/07/2002 — If you want to boost your heart health, a new study reported in the New England Journal of Medicine this week suggests you get moving and keep moving – as much as 20 miles a week. The results of the study conducted by Duke University Medical Center show that it is the amount of exercise, not the intensity of exercise, which made the biggest difference in altering cholesterol levels.”
Two more articles that say it’s the duration, not intensity of exercise that’s important.
“Even modest exercise may have cholesterol benefits”
Thursday, November 7, 2002 Posted: 12:32 PM EST (1732 GMT)
BOSTON (AP) — “Need another reason to exercise? Scientists have discovered it makes cholesterol less dangerous. A new study found that even modest exercise changes the size and density of cholesterol-carrying proteins so they do less damage.”
Now the exercise only needs to be modest.
“Study Shows Exercise Without Weight Loss Still Improves Cholesterol Levels”
David McAlary, Washington
“Overweight people might be pleased with a new U.S. study that shows they do not need to lose weight to improve the cholesterol levels in their blood. However, they must exercise.
But, low intensity exercise seems to be just as good as high intensity as long as there is enough of it.”
No mention that more exercise is better, only that you need enough of it.
In short, the study stands. However how it is reported is another story. It clearly says more exercise is better for lowering cholesterol. The emphasis seems to be that you don’t need to work hard to be healthy and even if you are still overweight, you can benefit. Leave it to the media to bring the good news to the lazy!