Some researchers did a study of other studies to try to determine what effect exercise has in reducing the risk of chronic disease in fat people. I will admit, I am not going to pay to read the full research paper.
In the abstract summary, the researchers say that exercise offers only a modest reduction in chronic disease risk for fat people.
I found that confusing because I believe that recently there has been quite a bit of research to the contrary. So first, I have to wonder what studies were these guys looking at. Recently may be part of the problem because part of the researchers’ criteria was to use studies dating before March 2010.
Other criteria included that the trials had to be randomized, at least 10 weeks duration, with a sample mean body mass index of greater or equal than 30, and the study had to report on things like blood pressure, blood lipids, glucose/insulin or C-reactive protein. Note – the study had to report on at least one of those factors, not all of them.
The researchers admit that there was a great “heterogeneity” (consisting of dissimilar elements or part) in responses to risk factors across the studies and the types of exercise used was heterogenous across the different studies. So lots of different kinds of exercise and lots of different responses.
And there was a problem in differentiating the effect of the physical activity independent of weight loss. In other words, what was causing the effect – losing weight or the physical activity?
The abstract summary concludes with: “The degree to which physical activity is effective at lowering risk factor levels among high-risk obese individuals is not known.”
Seems pretty clear. Basically they are saying “I don’t know.”
I don’t find that surprising, considering how many variables they were dealing with in looking at 44 different studies conducted by different researchers for different purposes.
How do you get from “Overall, physical activity had no more than a modest effect on chronic disease risk factors in obese individuals” to “The degree to which physical activity is effective at lowering risk factor levels among high-risk obese individuals is not known.” These statements seem to be contradictory.
“I don’t know” is a perfectly acceptable answer.