19 subjects, assigned sedentary or active based on habitual physical activity levels. Subjects were screened on basic health measures.
The problem with this is that people are sedentary or active for a variety of health-related reasons that are not captured in any screen (esp. the crude one used in this study). As a predictive study, this is fine, sedentarism predicts a lot of bad things. But it doesn't, on its own, suggest that becoming active is helpful. See also grip strength and mortality.
The principle of what you're stating is true, it could be correlational.
But there's an enormous volume of evidence that exercise, especially intense exercise, is better for health than any other intervention, including more sleep, quality of diet, pills+supplements (except those that treat an active illness/disease of course).
There's even compelling data showing that moderate drinkers who exercise live longer than non-drinkers who don't exercise. Even given that Alcohol is a powerful carcinogen.
The only thing proven more effective than exercise is weight loss really, if starting from high bodyfat levels.
(Anything above ~15% bodyfat in men seems to have negative implications for lifespan, and ~30% for women)
That sounds like a study that is pretty tough to control for, especially long term and at scale.
You'd need to find subjects that are provably capable of sustaining intense exercise as a habit if they wanted to but never did, and won't either for the years you'll be following them.
That won't work in the reverse, as people can be consciously or not self adjusting based on the health conditions you're trying to check.
PS: I'm remembering a friend who never liked running, but tried pretty hard after being pestered by their doctor and family, to discover that their knees are just not good and their whole lineage hated running for a reason. Intense exercise can be anything else, but people won't know their real health limitations until they actually do it for a while.
That intense exercise is good, and even very good for you, is proven as far as reasonably possible given that we can't run deterministically controlled experiments.
More evidence may come out that adds nuance, but the effect size is so large that it becomes obvious in the data just from observation.
You can cycle or stationary bike if you have bad knees. There are plenty of exercises that are intense but easy on the joints.
There (for example) is High intensity interval training.
What that is depends somewhat on who you ask but to give an example.
Take a normal exercise like cycling for 45 minutes.
If you do HIIT you cycle as fast as you can for 10-15 seconds (or until properly worn out) then rest long enough to be able to do it again. You only end up working out for less than one minute or just half a minute in total but you get similar if not better results than the 45 minutes workout.
So yes, running up the stairs as fast as you can until you feel like you are going to die would be high intensity. Take the elevator back down or you might die for real.
> You'd need to find subjects that are provably capable of sustaining intense exercise as a habit if they wanted to but never did, and won't either for the years you'll be following them.
With modern 24/7 health tracking we’ll have tons of data in the next 50-100 years. Problem is we need that much time to see the net effect and will probably be too late for most of you reading this.
I wouldn’t wait for the results though. Best to start moving now assuming it’s probably good for you.
I'd love to find out if electrical muscle stimulation while sleeping could effectively provide exercise without causing excessive sleep disruption. Could be a zero-effort supplemental form of exercise for sedentary people.
Carbon dioxide is produced as a metabolic waste product from exercise. Any sort of fat-burning you want to do is limited by the rate at which you can exhale CO2. This is why vigorous exercise is accompanied by heavy breathing. This includes not only cardiovascular training but also weight training. Lifting heavy weights will have you breathing very hard!
Unfortunately, if you don’t lift heavy (or if you use electrical stimulation that’s mild enough to sleep) then you’re not going to put your muscles into hypertrophy, so you won’t gain muscle mass either.
With respect to this idea, I'm not particularly interested in either of those goals. More the general longevity and health improvements that come with regular exercise irrespective of weight loss or muscle gain [1].
I haven't been able to find much in the way of research on the tolerability of EMS during sleep. I would be surprised if the idea is actually feasible. It just seems like it would be such a big win if it was.
Personally, I frequently toss and turn and breath heavily, and wake up with a high heart rate. But then, my sleep quality is terrible and when I got a sleep study the sleep phase diagram looked like a seismograph reading during a 4 hour long earthquake, so...
Well, it's causing muscle contractions. At high enough intensity, it should raise your heart rate. It's just a matter of what intensity level is tolerable during sleep (and the effect on sleep quality), no?
No, that would wake you up long before it had cardiovascular benefit. You need your heart rate up into zone 2 to 5 to really have a positive impact. That's 120 BPM plus for most people. Once you're around 80 it'll wake up anyone, even someone with very low cardiovascular fitness.
> mitochondria, which process energy within cells, showed a significantly decreased capacity to burn both sugar and fat in healthy individuals who get less than the recommended 150 minutes of exercise a week.
150 minutes a week is about than 22 minutes a day. Like 11 minutes twice a day. This looks like a really low effort to rid oneself of the risk of early decline.
I've seen studies like this before. They'll suggest that as little as 15 minutes of exercise significantly improves health in some group they studied. My initial assumption was they added 15 minutes of additional exercise. No, they studied people who did literally nothing. Then had them exercise 15 minutes a day.
As you might guess, their outcomes improved greatly.
The amount of time in the exercise advice keep getting shorter and shorter. The common advice when I was younger, in the USA, was an hour of exercise. Couldn't get enough people to do it. Then it was 30 minutes. Still couldn't get people to do it. Now the advice has been 15 minutes a day for a while, and we'll still not be able to get people to do it.
The environment and culture needs to be structured such that people get the exercise they need "naturally". The vast majority aren't going to go out of their way for it.
That's a big part of why zoning is so dangerous. In most of the western world (Europe too on average), we pushed down population density so much that your typical destinations are much less likely to be within walking distance, so you don't walk.
Indeed. In NYC I do 98% of my shopping by walking. I can reach my doctor by walking. My daughter used to walk to school because it was a 10 minutes walk (and an excellent school).
That would be impossible in a suburban setting; at best, one of these destinations would be within the theoretical waking distance, but without the walkways.
This is sadly not a rare type of person. I'm worried my parents fit this description, they drive everywhere and work an office job. I'd guess on average they get 0 minutes of exercise a day.
I think people get this image in their head that someone who doesn't exercise ever is this comically fat unemployed person when in reality it's the average office worker who isn't fitness minded. A good chunk of HN users wouldn't be getting 15 minutes of exercise a day.
A lot of people who use a car to get around will spend most days doing literally no actual exercise. For someone who lives in a more walkable area, 22 minutes of exercise is just living live normally without actively "exercising".
A studied showed that elderly asians have better health outcomes that their western counterparts in part due to their practice of sitting on the floor. The added exertion of standing up from the floor rather than a chair makes a material difference in their health.
Some of the health tests in Japan that elderly people take include a "standing to sitting on the floor and getting back up all unsupported" test. Scores are based on time, effort, emitted sounds (like grunts), hands-on-ground and whatnot. I don't know the specifics, but it is used as a "health measure."
I remember reading somewhere that one of many long life markers is if you can go from sitting on your butt straight into standing without your hands or knees touching the floor.
I was busy building a sensorless maintenance calorie tracker.
Sometime back i posted this on HN: https://news.ycombinator.com/item?id=48614890
It also has "sedentary" detection which i find pretty useful for the phases when my activity level drops, reduced activity directly reflects in your maintenance calories which maybe useful to some.
It would be cool if one could safely adapt to modern life (lots of sitting, required focus over long sessions) without having to spend time exercising if they don't want to (to be clear, some people want to). Imagine if you could just take something to get all the benefits of exercise, without having to actually spend the time. That'd be pretty great for everyone if it truly was safe and without downsides (skeptical).
They make stationary bikes that fit under a desk. I've never used or seen one, but they exist. I considered getting one during 2020, but they seemed impossible to source.
What if we could just lay in a pod 24/7 taking peptides and nutrient supplements while having an endless stream of instagram reals beamed in to our eyeballs on our Meta Raybans. That way we would never have to do pesky things like go outside or move.
On the other hand, a pill to replace all the un-fun activity needed to stay in shape while having a family and office job would let you enjoy fun activity a lot more, and want to do those things more often, since they’re all more-fun and safer if you’re already in shape.
The problem with this is that people are sedentary or active for a variety of health-related reasons that are not captured in any screen (esp. the crude one used in this study). As a predictive study, this is fine, sedentarism predicts a lot of bad things. But it doesn't, on its own, suggest that becoming active is helpful. See also grip strength and mortality.
But there's an enormous volume of evidence that exercise, especially intense exercise, is better for health than any other intervention, including more sleep, quality of diet, pills+supplements (except those that treat an active illness/disease of course).
There's even compelling data showing that moderate drinkers who exercise live longer than non-drinkers who don't exercise. Even given that Alcohol is a powerful carcinogen.
The only thing proven more effective than exercise is weight loss really, if starting from high bodyfat levels.
(Anything above ~15% bodyfat in men seems to have negative implications for lifespan, and ~30% for women)
That sounds like a study that is pretty tough to control for, especially long term and at scale.
You'd need to find subjects that are provably capable of sustaining intense exercise as a habit if they wanted to but never did, and won't either for the years you'll be following them.
That won't work in the reverse, as people can be consciously or not self adjusting based on the health conditions you're trying to check.
PS: I'm remembering a friend who never liked running, but tried pretty hard after being pestered by their doctor and family, to discover that their knees are just not good and their whole lineage hated running for a reason. Intense exercise can be anything else, but people won't know their real health limitations until they actually do it for a while.
That intense exercise is good, and even very good for you, is proven as far as reasonably possible given that we can't run deterministically controlled experiments.
More evidence may come out that adds nuance, but the effect size is so large that it becomes obvious in the data just from observation.
You can cycle or stationary bike if you have bad knees. There are plenty of exercises that are intense but easy on the joints.
Looking around, the simplest wording I get:
> the intensity must be high. This means that you need to really exert yourself so you get out of breath. [https://norwegianscitechnews.com/2026/05/exercise-a-very-lit...]
So if climbing the stairs gets someone out of breath it's intense (and I also see how getting to your limits, whatever they are, can help)
What that is depends somewhat on who you ask but to give an example.
Take a normal exercise like cycling for 45 minutes.
If you do HIIT you cycle as fast as you can for 10-15 seconds (or until properly worn out) then rest long enough to be able to do it again. You only end up working out for less than one minute or just half a minute in total but you get similar if not better results than the 45 minutes workout.
So yes, running up the stairs as fast as you can until you feel like you are going to die would be high intensity. Take the elevator back down or you might die for real.
More and more studies have been indicating that even just a few minutes of intense exercise can outperform long/slow LISS type cardios.
E.g. 5m all out effort is probably better, or at least equivalent, for health than a 30m moderate effort.
The average person can likely hit the 80/20 benefit threshold at less than 30m/week.
With modern 24/7 health tracking we’ll have tons of data in the next 50-100 years. Problem is we need that much time to see the net effect and will probably be too late for most of you reading this.
I wouldn’t wait for the results though. Best to start moving now assuming it’s probably good for you.
Can you link evidence for this? I stay at 12% year around as male (confirmed via DEXA)
https://www.acpjournals.org/doi/pdf/10.7326/M15-1181
Though to be clear, there aren't a ton of studies that look at bodyfat percentage. Most use BMI and similar measures.
Likely overall fat levels matter more than %, I'd guess.
E.g. I'd presume being 15% at very muscular levels is less healthy than 15% at moderate.
(Because absolute fat mass plus visceral fat would be higher)
Unfortunately, if you don’t lift heavy (or if you use electrical stimulation that’s mild enough to sleep) then you’re not going to put your muscles into hypertrophy, so you won’t gain muscle mass either.
I haven't been able to find much in the way of research on the tolerability of EMS during sleep. I would be surprised if the idea is actually feasible. It just seems like it would be such a big win if it was.
Personally, I frequently toss and turn and breath heavily, and wake up with a high heart rate. But then, my sleep quality is terrible and when I got a sleep study the sleep phase diagram looked like a seismograph reading during a 4 hour long earthquake, so...
1: https://theconversation.com/exercise-extends-life-even-witho... (Maybe not a great source but I think there is a wealth of evidence for this)
150 minutes a week is about than 22 minutes a day. Like 11 minutes twice a day. This looks like a really low effort to rid oneself of the risk of early decline.
As you might guess, their outcomes improved greatly.
The environment and culture needs to be structured such that people get the exercise they need "naturally". The vast majority aren't going to go out of their way for it.
That would be impossible in a suburban setting; at best, one of these destinations would be within the theoretical waking distance, but without the walkways.
I think people get this image in their head that someone who doesn't exercise ever is this comically fat unemployed person when in reality it's the average office worker who isn't fitness minded. A good chunk of HN users wouldn't be getting 15 minutes of exercise a day.
If I drive, it takes me 15 minutes (Toronto traffic is horrible). So doesn’t even gain me much in terms of time.
Just sad that temperatures here drop so low I don’t want to walk for half the year lol.
https://duckduckgo.com/?q=desk+stationary+bike
That's better than what i'm doing, hunched over my desk with the metabolic rate of a sleeping lemur, but...it's a slow stroll.