Breaking it down and getting perspective: “Exercising 300 minutes per week better for reducing total fat in postmenopausal women”

I hate these headlines.  It’s not that this is not true, it’s just that it conveys inaccurate information.

This suggests that if you want a healthy, normal body weight and to work towards preventing cancer later on in life, it will require 5 hours a week, or 10 days a year, or a year and a half of your adult life.  Naturally, as a result of seeing these kinds of headlines, fewer people will recognize fitness as something obtainable.  Which is a shame because lack of exercise is a major cause of chronic diseases.  And isn’t this article was written to inform women as to how to stay healthy as they age?  Just saying.

Also, by the way, a whole article was actually written by a  science writer.  Real people took a year out of their lives to produce this study. It’s disappointing that I now take time out to write this blog because we’ve become a society of headline readers with the attention span of a goldfish.  I digress, as usual.

Now then, the first rule when confronted by an outrageous headline is to remember that the scientists who conduct these studies don’t create the headlines. The headlines are created to get you to click — hopefully on a diet pill ad on the site.

Second rule: don’t be a sheep.  Actually read the article.  It’s chock full of information.

You have the headline, now here’s a summary of the article that produced it.  Click anywhere on it to link to the full article on ScienceDaily.

Date:  July 16, 2015

Source:  The JAMA Network Journals

Summary:  Postmenopausal women who exercised 300 minutes per week were better at reducing total fat and other adiposity measures, especially obese women, during a one-year clinical trial, a noteworthy finding because body fat has been associated with increased risk of postmenopausal breast cancer, according to a recent article.

The short article in ScienceDaily is a summary of a study.  These SD articles usually don’t tell much, but you can always click the link to the actual study.  I did, and here are a few things of note.

  1. The study is entitled “Effects of a High vs Moderate Volume of Aerobic Exercise on Adiposity Outcomes in Postmenopausal Women: A Randomized Clinical Trial,” and was conducted by the Department of Cancer Epidemiology and Prevention Research, CancerControl Alberta, Alberta Health Services, Calgary, Alberta, Canada  
  2. This is an article about cancer prevention published in JAMA Oncology.
  3. The women in the study were inactive and had a BMI of 22-40, so they were overweight to obese.
  4. They were asked not to change their diets. So they were only looking at the effect of a particular kind of exercise on weight loss, not investigating the best way to lose weight, a subject way too broad for a study.
  5. The participants largely self-reported.That means they kept logs of their activities and reported to the University.  Often that’s how these things are done, the alternative being that scientists must  follow participants around all day long to ensure compliance.  Not practical.
  6. There is no accounting for intensity in this study. Again, not a study about that.   What difference does intensity make?  You must be new to my blog.  Essentially there are three measurements for activities/exercise:  intensity, duration and frequency.  These three measurements are inversely proportional, meaning when one goes up, the others have to go down.  The training here doesn’t differentiate in terms of intensity, only overall volume.  The volume of exercise is broken up into frequent bouts of exercise which have to be longer in duration.  Whether it’s 2.5 or 5 hours a week, those are both high volumes (higher frequency AND higher durations).  So intensity was obviously low.
  7. In addition, nothing seems to change over the course of a year.  There is no reporting of increases in intensity as the participants become better at exercising. One assumes participants simply maintain the same routines over and over. Perhaps they’re walking one day and water aerobics the next, but the level of effort and volume is essentially the same.  The overall time is what is recorded.
  8. These ladies were inactive prior to the study.  As someone who trains heretofore inactive older people, that’s a hard transition.  It can take months to get inactive and overweight folks up to levels of training intensity that are super effective.
  9. In case you are not following me, there’s no way these ladies had the advantage of higher intensity training. So this study is not a “better than high intensity.”  The headlines just simply reads an open ended “better.”

Yes.  If you are overweight and you don’t change your diet, creating a significant negative energy balance (calories in minus calories out) will occur by using lower intensity exercise done in VOLUMES.  And the more the better.  At least until you can do higher intensities, which could create more lean mass and raise metabolism and over the the haul create a greater calorie deficit, all other things being equal.

But here’s the thing.  Exercise, in any intensity, is less effective than any of us want to acknowledge in creating a negative energy balance.  And you can’t outrun a bad diet. The most effective way to create a negative energy balance, regardless of exercise modality, is  … [dramatic music] …DIETING.

So must you waste 5 hours a week over the course of a year on exercise to accomplish the goal of losing weight and therefore lowering your risk for cancer, as the headline suggests?  Oh hell no. That’s an “also ran,” useful only in the presence of an absolute refusal to eat less, or in the absence of a more efficient protocol, like High Intensity Training.  But you know, a good HIT trainer can be hard to come by.  And we ain’t cheap!  Except for in New Orleans.  In New Orleans, there’s a few of us and we’re less than most everywhere else.  Digressions.

Also, in case you missed it — note to self:  start down the fitness path sooner in life!  It’s so much better to get a head start than to try and play catch up when you’re old and tired.

That’s all for now.


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