Association vigorous intermittent lifestyle physical activity with mortality
nature.com
nature.com
We should be very nervous about any results that depend on this many adjustments. Remember: If their measure of smoking history is crude or inaccurate, this basically means they only "half control" for it.
What I would love to see in this kind of a study is what the strength of the association is WITHOUT adjusting for anything and then show how it changes as more adjustments are added. If the association drops a lot with each adjustment, then we should be suspicious that enough controls haven't been included or the controls are too noisy.
Of course, at the end of the day, nothing substitutes for an RCT. These kinds of observational studies are worth thinking about even though they are much less informative, given that they are orders of magnitude cheaper. It's just worrisome that most popular reporting doesn't seem to recognize how much less they should be trusted.
It's a great journal in terms of metrics, but more often than not they publish things that look interesting but not very robust.
For example, most studies that do multivariate analyses (not applicable here) do not do partial pooling. Hence, they end up with inflated effect sizes.
Nature Genetics is also letting this happen all the time, which is annoying and leads to non-reproducible findings.
But you must realise that effects would be entirely obscured without corrections. That's just the central limit theorem.
But I think this thread misses the main thrust of the research.
Next time you read a paper about someone living longer for say. Combing their hair think, should they have corrected for VILPA?
My issue with these studies from the UK Biobank though is that the wearable devices are only worn for up to 2 weeks or so, although the follow period is significantly longer in this study. For this study the "participants were required to have at least three valid monitoring days, with at least one of those days being a weekend day". Would be better to have a prospective cohort but good to see associations so further studies can investigate.
Yes, someone who is unable to climb the stairs might not be long for this world but...making them sprint up a staircase is unlikely to prolong (rather than shorten) their lives.
The smartest way to do it is probably to increase both frequency and intensity progressively, which means your body can make small adaptations over time without putting undue stress on the joints, tendons, bones, cardio-vascular system etc.
Those can then cause a stroke when they obstruct blood flow to something critical. The stroke may be fatal, or maybe you just loose capabilities like motor control of half your body.
Either way, there's a reason many people are advised to consult with their physician before beginning an exercise regimen.
Stay active folks...
Also, I can't help wondering whether this study's results are applicable to what they call a "stress test" at your doctor's. Or is that beyond the regime they were examining.
The direction of causation could be reversed too. It might be that inactivity is a sign of deteriorating biological systems.
I think we could probably agree with this advice based on strong priors but this paper provides poor support for the advice since it's not an intervention, it's an observation of extreme sedentary "lifestyles" which are probably heavily skewed towards various forms of illness (or infirmity from old age).
> VILPA was inversely associated with all three of these outcomes in a near-linear fashion
I think the title (in the paper itself, and therefore also in the HN submission) is misleading. Title should be "...with lower mortality"
Seems like a really low bar for someone without disabilities. Doesn't this association read too much into it?
I mean if someone is so physically disconditioned that this level of activity is not the case (excluding disability) then yeah that kind of sedentarism seems like a recipe for CVD.
maybe people with atrial fibrillation make up a disproportionate fraction of the lower-vilpa groups, for example, because walking up stairs fast leaves them lightheaded, so they walk up stairs slowly instead, and later the fibrillation kills them at high rates
doesn't mean walking up the stairs fast would be good for you if you have afib
Saying, "Eat good food and exercise more" is very general, whereas "Get 10 minutes of intense exercise per day" or something like that is more measurable and actionable, especially with the use of wearables...
This might sound ridiculous, but some people even equate calls for exercise with fat-shaming. I've seen complaints like that posted in internal FAANG newsgroups as a response to events encouraging people to do exercise.
And it may act as a motivator. How many people end up being literally petrified by the prospect of having to spend a few hours exercising every week? And rather not exercise at all.
On the bottom line, it may help improve the health of a cohort that does not currently exercise at all.
".. sample median VILPA frequency of 3 length-standardized bouts per day (lasting 1 or 2 min each) " vigorous intermitant lifestyle physical activity ?
apparently this is a study regarding seniors and elderly, and instilling a habit of doing something "vigorous" for less than five minutes, a few times each day
— ChatGPT Summary
It would be a shortening of
> Wearable devices can capture unexplored movement patterns such as brief bursts of vigorous intermittent lifestyle physical activity (VILPA) that is embedded into everyday life, rather than being done as leisure time exercise
When you compose a summary, it is paramount that you understand the original text. Otherwise, the product would be a bad report. An example of misunderstanding is already that first sentence 'Wearable devices ... time exercise'. It does not express what the Abstract of the submitted article expresses. It is not a good summary.