Fulltext: <a href="https://www.dropbox.com/s/gfch760k1ratwo3/2015-rottensteiner.pdf" rel="nofollow">https://www.dropbox.com/s/gfch760k1ratwo3/2015-rottensteiner...</a> / <a href="http://sci-hub.org/downloads/045f/10.0000@pdfs.journals.lww.com@generic-FD16BBD9129B.pdf" rel="nofollow">http://sci-hub.org/downloads/045f/10.0000@pdfs.journals.lww....</a><p>Buried some interesting points there:<p>> The researchers were looking for young adult identical twins in their early- to mid-20s whose exercise habits had substantially diverged after they had left their childhood homes. These twins were not easy to find. Most of the pairs had maintained remarkably similar exercise routines, despite living apart.<p>Besides the testament to how 'everything is heritable' inherent in that observation, it also raises the question: if they are so unusual, doesn't that make confounding more plausible?<p>> Interestingly, the twins tended to have very similar diets, whatever their workout routines, so food choices were unlikely to have contributed to health differences.<p>Also very interesting, and counter to the usual narratives about health. (Everything is heritable...)<p>> The twins’ brains also were unalike. The active twins had significantly more grey matter than the sedentary twins, especially in areas of the brain involved in motor control and coordination.<p>Warning sign: 'significantly'. Does this mean, as any ordinary person would take it to mean (in conjunction with that lazy stock photo), 'a lot' or does it mean 'p<0.05'?<p>Trick question, of <i>course</i> it means the latter, which is useless! Take a look at the fulltext, pg6, table 2, which spits out the <i>actual</i> differences between the twin pairs. I hope you're ready to be wowed by how much difference an exercise regimen makes when you control for genetics (picking out a few I recognize):<p>1. BMI: -0.8<p>2. VO2max: 6.3<p>3. weight: -2kg<p>4. waist circumference: -3.3cm<p>5. fat percentage: -3.3 (!)<p>6. lean mass: 1.4kg<p>I'm not sure I've seen such a damning indictment of exercise in a long time. (Less than 1 on BMI? 2kg of weight? I fluctuate more than that on a weekly basis...)
>But eventually the researchers homed in on 10 pairs of male identical twins, one of whom regularly exercised, while the other did not, usually because of work or family pressures, the researchers determined.<p>That "work and family pressure" sounds like stress and a pretty important confounding variable.
The full data set seems to show that the strongest argument in the article is that propensity to fitness is mostly a result of genetics and upbringing - it was apparently very difficult to find twins where the level of fitness was different, and very difficult to find twins with significantly different dietary preferences. This seems to indicate that in most cases, your level of fitness is basically pre-determined by age 18.
<i>we can “move more,”</i><p>surprisingly this is difficult, not impossible.<p>Back in 2007 I did a simple experiment myself asking, <i>'at what point do you fail when repeating exercising?'</i> The idea was pretty simple: pick a arbitrary impossible distance to cover and move each day to reach it. The impossible distance I chose 1000km in a year.<p>So I selected a difficult 10km source and set out each day moving 10km per day until I complete my target. I reached my target by late November and decided to push-on to 1000Ml (1600Km), the last 400 in 20 days.<p>The key failure point I found? Just before I started. If you could psychologically push through <i>any</i> excuse made not to go, just before you started, It's pretty likely you will start and finish. I keep this up averaging about 2000km/yr using that insight into failure. Up to 300km so far this year (with min/max 1kg weight and 8kg pack).
I'll admit I didn't read the study but the results summarized in this post don't seem very interesting:<p><i>The sedentary twins had lower endurance capacities, higher body fat percentages, and signs of insulin resistance, signaling the onset of metabolic problems.</i><p><i>The active twins had significantly more grey matter than the sedentary twins, especially in areas of the brain involved in motor control and coordination.</i><p>Isn't this expected to anybody not exercising vs. someone who is?<p>It would have been interesting to see if there were results beyond the obvious effects of exercising.
I always find it interesting that whenever exercise/diet topics come up on HN that people will go to the n-th degree to try and discredit or rubbish the studies. Could it be a bias in the stereotypical geek which shuns both these habits and so seeks an intellectual reason to justify his sedentary lifestyle?
Can someone explain to me why an identical twin is allergic to mushrooms and the other one is not? Also why a symmetric identical twin is more friendly/outgoing and speaks fluently while the other one is opposite?
I wonder if they took in account the fact that, as they say, the twin that stopped exercising did so reluctantly and in response to some social or family pressure. In other words, they're comparing a person who keeps doing what he always liked to do with another that had to give up. I'm not sure the result can be transferred to people who never felt the urge and benefit of exercising. How would compare two twins, one of which has only in recent years being forced to exercise?
From the report:<p>"The scientists invited these twins into the lab and measured each young man’s endurance capacity, body composition and insulin sensitivity, to determine their fitness and metabolic health."<p>Shame they couldn't find twins that took part in strength training, but not surprising given the difficulties in finding any participants.
"But eventually the researchers homed in on 10 pairs of male identical twins, one of whom regularly exercised, while the other did not, usually because of work or family pressures, the researchers determined."<p>Oh boy... How can 10 possibly be enough?
> The active twins had significantly more grey matter than the sedentary twins, especially in areas of the brain involved in motor control and coordination.<p>Is that good or bad?