Healthy but sedentary people show early decline in cellular energy production

7/1/2026 at 11:21:30 PM

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.

by jsw97

7/2/2026 at 12:07:32 AM

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)

by adam_arthur

7/2/2026 at 12:18:31 AM

> specially intense exercise

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.

by makeitdouble

7/2/2026 at 12:22:34 AM

A large volume of studies already exist.

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.

by adam_arthur

7/2/2026 at 12:38:49 AM

I am aware of that for exercising, but was ignorant of what "intense" actually means in this context. And you're right.

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)

by makeitdouble

7/2/2026 at 12:44:36 AM

Yeah, typically "intense exercise" is implying HIIT style cardio.

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.

by adam_arthur

7/2/2026 at 1:45:15 AM

> More and more studies have been indicating that even just a few minutes of intense exercise can outperform long/slow LISS type cardios.

For best results run fast and far. During my personal best marathon (3h 15min) my heart rate averaged in the 170 range

by Swizec

7/2/2026 at 6:25:01 AM

How old were you at the time? Mid 40s here and can comfortably sustain low 150s, but burn out quick past 160.

by Earw0rm

7/2/2026 at 2:21:15 PM

Mid 30s

by Swizec

7/2/2026 at 8:10:56 AM

HIIT vs LISS is a false dichotomy. If you look at endurance athletes the most important part of the training is in "heavy domain" that is between what typical LISS and HIIT are. This is intensity high enough that you need to breathe faster but it's still sustainable for at least 40-70 minutes.

>>E.g. 5m all out effort is probably better, or at least equivalent, for health than a 30m moderate effort.

This is very unlikely to be true. Studies I've seen usually compare low intensity to HIIT and then measure things like VO2max improvements instead of direct health outcomes. VO2max is a good health indicator for general population and it's maximized short term by HIIT style of training but it's not enough to conclude short term improvements in VO2max imply long term health.

>>The average person can likely hit the 80/20 benefit threshold at less than 30m/week.

I very much doubt it. Usual number mentioned is at least 5 hours but in general the more the better.

by bluecalm

7/2/2026 at 1:31:20 PM

A 40-70m sustained effort is effectively LISS from a study perspective. The main distinction being made is intensity, and it's impossible to sustain even a marginally intense effort for 40m (unless you redefine "intense" as different from what most studies use)

Recent studies have shown compelling evidence that LISS promotes arterial plaque buildup, while HIIT does not have this effect and has even been shown to reverse it if other parameters are in order.

https://www.ahajournals.org/doi/10.1161/CIRCULATIONAHA.119.0...

"""

Physical activity and exercise training are effective strategies for reducing the risk of cardiovascular events, but multiple studies have reported an increased prevalence of coronary atherosclerosis, usually measured as coronary artery calcification, among athletes who are middle-aged and older. Our review of the medical literature demonstrates that the prevalence of coronary artery calcification and atherosclerotic plaques, which are strong predictors for future cardiovascular morbidity and mortality, was higher in athletes compared with controls, and was higher in the most active athletes compared with less active athletes.

"""

While the health benefits of LISS seem to outweigh this factor, the new evidence that comes out in various studies continually nudge health impact of HIIT over LISS.

I find it difficult to recommend a form of cardio that 1) promotes arterial plaque over one that reverses it, and 2) seems to produce equivalent or worse biomarkers along almost every axis per unit of time spent.

(Not just V02 max)

by adam_arthur

7/2/2026 at 1:06:32 AM

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.

by econ

7/2/2026 at 8:15:51 AM

>>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.

You will improve things like muscle buffer capacity and maybe VO2max (although for that longer intervals are much better) but those are not the most important things for metabolic health or health in general.

Recommending sprinting to untrained people is just a very bad idea. Fatigue and injury risk is higher. Benefits when it comes to metabolic health are lower.

It's important for exercise to be in heavy domain. Maybe it's a good idea to be in severe domain for a while (VO2max training) but typical HIIT hacks maximize pain/injury risk/recovery time while giving less benefits (unless you compare it to something silly like strolling for 30 minutes).

by bluecalm

7/2/2026 at 1:03:24 AM

> 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.

by koolba

7/2/2026 at 12:58:49 AM

I challenge you to look for studies. Read a few. There are hundreds on this topic!

by Schiendelman

7/2/2026 at 12:24:55 AM

>(Anything above ~15% bodyfat in men has negative implications for lifespan, and ~30% for women; when reviewed at scale)

Can you link evidence for this? I stay at 12% year around as male (confirmed via DEXA)

by faangguyindia

7/2/2026 at 12:53:14 AM

The claim comes from this study:

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)

by adam_arthur

7/2/2026 at 3:49:15 AM

Sounds like absolute BS to me. Even in very large scale studies specifically designed for studying mortality, only morbid obesity has been negatively correlated with lifespan. There is even some evidence that being a little overweight is actually helpful for the very old (essentially, because it gives them more buffer if they get sick enough that they stop eating for a while). A lot of this is because modern medicine has gotten very good at treating stuff like diabetes and other stuff caused by obesity. Your quality of life will undoubtedly improve if you are thinner, but that's not the same thing.

by Jweb_Guru

7/2/2026 at 4:46:46 AM

https://pubmed.ncbi.nlm.nih.gov/36756765/

Lowest risk is around 18-20 BMI in this recent study, which controls for many confounding factors not controlled for in other studies.

Other studies show slightly higher troughs, but often don't sufficiently control for correlation of weight with health in elderly people.

From this study: Estimates of mortality differences by body mass index (BMI) are likely biased by: (1) confounding bias from heterogeneity in body shape; (2) positive survival bias in high-BMI samples due to recent weight gain; and (3) negative survival bias in low-BMI samples due to recent weight loss

And if you follow the longevity/health space and studies as they come out, it's becoming pretty clear that bodyfat is objectively bad for you above a pretty low baseline.

It shows up in insulin resistance, heart markers, inflammation, and once you control for confounding factors sufficiently, mortality.

You likely won't become diabetic with a bodyfat of 25%, but all your health markers will be worse than somebody at 15%. This is measurable and clear.

by adam_arthur

7/2/2026 at 1:34:57 PM

If a single article in a low-impact journal cited by a handful of other articles is the only evidence you have, you're guilty of cherrypicking, I'm afraid. The article you're citing is clearly a response to the current medical consensus.

by Jweb_Guru

7/2/2026 at 1:41:37 PM

There are hundreds of studies indicating that each marginal additional unit of bodyfat is less healthy for you than not having it.

You are quoting poorly done and controlled BMI studies to dispute this, studies which look primarily at elderly people where weight is highly correlated with health to begin with and is not properly controlled for along every axis.

I'm not here to litigate it or convince you though.

by adam_arthur

7/2/2026 at 3:20:20 PM

"Less healthy" is distinct from "shortens lifespan" which was pretty much the entire point I was making.

I understand that the idea that there are well-controlled massive studies with enough power to detect differences from weight alone is appealing, but they simply aren't there -- which should tell you that even if the effect exists, it's not strong enough that it should be your primary motivation to lose weight. There are already plenty of reasons to lose weight that don't require lying to people about having a BMI > 20 shortening your lifespan.

by Jweb_Guru

7/2/2026 at 5:59:47 AM

BMI, in many cases, is considered a poor measure of health.

https://www.sciencefocus.com/comment/bmi-we-know-its-flawed-...

by IndySun

7/2/2026 at 1:40:49 PM

Yes it is but most of the studies use it, so that's the data we have.

And the OP implicitly referenced these studies in his claim that being overweight could be healthier (which comes up in BMI studies of elderly people that don't sufficiently control for confounding factors)

by adam_arthur

7/2/2026 at 5:28:41 PM

It was my intention to add some background detail, for anyone not aware, or wanting a side dive, about how BMI stands 'these days'. As such, it can be said the variables may be considered wider than they may appear at first (in the article conclusions). Which is a roundabout way of saying we all 3 are agreeing.

Je n’ai fait celle-ci plus longue que parce que je n’ai pas eu le loisir de la faire plus courte.

by IndySun

7/2/2026 at 4:33:21 AM

[dead]

by andsoitis

7/2/2026 at 12:45:42 AM

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.

by strbean

7/2/2026 at 1:26:49 AM

I just named my dracula training program.

First, learn to sleep on your back

Second, attach the blanket to the bottom of the bed and learn to sleep with your knees up. Use the blanket to help.

Third, put some books under the legs (on the head end)

Keep adding books until you almost slide down, get used to it and add more books.

Eventually you wake up feeling like you did a proper leg day.

Keep at it and go for isometric nucleus overload. Every 6 weeks remove half the books for 2 weeks.

You will grow enormous legs and they will stay that way.

I suppose you could tie rubber bands to your arms in stead of the books but I haven't tried that. I'm sure it will make for a memorable period of your life. ha-ha

by econ

7/2/2026 at 1:00:07 AM

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.

by chongli

7/2/2026 at 1:11:26 AM

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...

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)

by strbean

7/2/2026 at 1:39:28 AM

Ok well here is a general longevity-related reason why resistance training is important.

Lifting weights also increases bone mass. As you get older, osteoporosis becomes more and more of a concern. You fall one day, and the less bone mass you have built up, the more likely it is that you will lose mobility. There is a strong link between reduced mobility and cognitive decline and also a cascade of other health problems. Old person + hip fracture = significantly increased mortality, and the way to prevent this is by building up bone mass while you still can.

by DrJokepu

7/2/2026 at 2:46:23 AM

I hear some people fix their sleep problems by staying awake much longer for some days then follow a strict schedule.

For me, after physical activity sleeping is much easier but if i over do it cortisol wil make it worse. (I once created an exercise formula that kept me awake long enough I started hallucinating) Spinach does miracles for me, the magnesium folate and flavonoids lower cortisol. Popeye was apparently on to something.

YMMV

by econ

7/2/2026 at 12:59:31 AM

It can't, because it isn't training your heart and cardiovascular system.

by Schiendelman

7/2/2026 at 1:06:13 AM

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?

by strbean

7/2/2026 at 1:10:56 AM

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.

by Schiendelman

7/2/2026 at 3:10:58 AM

I read with the right dream (nightmare) heart rate can climb to 180.

If you slowly condition yourself I think you can exchange sleep quality for increased heart rate.

But I suspect the heart needs rest too and you will die.

An isometric hold would be better I think. You don't get any vo2max improvement but it does improve cardiovascular health.

by econ

7/2/2026 at 3:16:11 AM

That's an interesting idea. Do you know if anyone's tried it?

by Schiendelman

7/2/2026 at 3:30:25 AM

https://news.ycombinator.com/item?id=48755297

by econ

7/2/2026 at 1:16:06 AM

> Once you're around 80 it'll wake up anyone

Source? I haven't been able to find info on this. I get resuls on nocturnal tachycardia and such. Nothing on elevating a sleeping person's heart rate and observing the result, though.

by strbean

7/2/2026 at 2:27:17 AM

To be clear, if you implanted a lead, you might not wake them up. It's the mechanism by which you would raise their heartrate that would wake them - the same things that elevate heartrate from external stimulation would also cause cortical arousal.

by Schiendelman

7/1/2026 at 11:22:20 PM

> 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.

by nine_k

7/1/2026 at 11:44:08 PM

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.

by sidewndr46

7/1/2026 at 11:47:19 PM

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.

by SchemaLoad

7/2/2026 at 5:58:55 AM

Looking at a few friend's health app on their iPhone it's amazing to me to see people who walk less than 2,000 steps a day and don't go to the gym. It's shockingly normal in some places though.

by jraby3

7/2/2026 at 12:43:16 AM

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.

by xboxnolifes

7/2/2026 at 1:01:00 AM

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.

by Schiendelman

7/2/2026 at 1:09:18 AM

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.

by nine_k

7/2/2026 at 7:48:20 PM

Really depends on the suburb. Where I live in NYS (a suburb of Buffalo) all of those things are within walking distance if you live within the village limits.

by camdenreslink

7/2/2026 at 8:07:46 AM

> That would be impossible in a suburban setting;

Not necessarily true. The "village center" idea Jim Rouse used in his design of Columbia, MD could be used to solve the problem.

All of these things are within walking distance if you live in Columbia's village of Wilde Lake (and, of course, your health insurance covers the primary care physicians in walking distance).

I'm guessing you're thinking of typical "stroad" suburbs, but alternatives are possible and do exist.

Unfortunately, the suburb has to be the product of planning like Columbia. Typical "emergent" suburbs turn into unwalkable ones.

by acuozzo

7/2/2026 at 3:25:49 PM

The fact that alternative designs are possible is almost irrelevant, because the problem is that you don't get people to agree on the same things. You get one example of something like that and it never replicates.

If you want public health outcomes, actual scale, you get much better outcomes by not having that regulatory system at all.

by Schiendelman

7/2/2026 at 1:11:34 AM

Absolutely. There's a reason body fat percentage in New York City is so much lower than anywhere else in the US!

by Schiendelman

7/2/2026 at 2:19:36 AM

This is something I've visually observed all over Australia. The walkable areas are noticeably fitter. I don't think all of those people just happen to care about fitness more, they just spend more time moving to get between places rather than sitting all day.

by Gigachad

7/2/2026 at 2:24:51 AM

Absolutely! Fitness scales super closely with localized population density.

by Schiendelman

7/2/2026 at 6:46:42 AM

This is a recent phenomenon.

The original reason for low population density was agricultural work, which - even in the early days of mechanisation - was plenty physical.

Living in exurbia to work and consume like a city dweller is a new kind of stupid.

by Earw0rm

7/2/2026 at 12:08:44 PM

Yep, and we caused it, through the massive subsidy to cars that was the federal highway program. Many tranches of spending, from ~1937 forward, caused this.

by Schiendelman

7/2/2026 at 2:11:24 AM

Yeah pretty much the only way to scale exercise to entire populations and over entire lifetimes is to design it directly into the cities.

by Herring

7/2/2026 at 2:24:04 AM

The crazy part is you don't even have to DESIGN it, the market is desperate to build walkable density because it's so much more profitable than anything else. You just have to LET landowners build upward.

by Schiendelman

7/2/2026 at 2:31:32 AM

But then you'll run into traffic/parking issues unless you have a good public transit and land use policy (e.g. bikes, trams, mixed use development, etc). That requires such good design skills few cities have mastered it (Tokyo, Copenhagen, Singapore).

by Herring

7/2/2026 at 2:48:01 AM

I know it seems this way, but all you have to do is not subsidize driving with government provided parking, and not build highways, and there's no traffic problem, because people don't get cars in the first place - they don't have anywhere to put them and there's no highway to punch through dense neighborhoods. Transit and bike infrastructure can always be built after the fact through public demand. When you let go, the people who WANT to live in high density without cars FLOCK to what gets built.

In fact, if you really stop zoning, there's a decent chance companies will ASK to operate transit for you, because those population densities and no free car competition can make it profitable. This happens in many cities!

Mixed use development happens if you let it happen. Banks and developers like money, and mixed use makes way more money, so they want to build it. Sometimes they fuck up and don't, and those land owners pay the price and retrofit. And that's fine. Again, just let them.

In high engagement Western societies, where people get involved in politics and urban planning, "design" universally leads to car subsidies and shitty outcomes. The market does a way better job.

by Schiendelman

7/2/2026 at 4:10:57 AM

It really doesn't take that much at all. You just have to allow apartments and mixed use zoning, and not actively chop up the land with stroads.

Human populations naturally gravitate towards walking, and it's pretty much active sabotage of the outside environment that has broken this.

by Gigachad

7/2/2026 at 4:05:05 PM

You're right, of course!

The hard part is "just". If you have mechanisms that allow neighbors to have an opinion at all, they will organize around it, they will stop growth, and you will eventually get San Francisco and New York restrictions anywhere that has high demand.

by Schiendelman

7/2/2026 at 12:23:53 AM

HN is always so sarcastic on this point, but a large part of the population is not getting 15-30 minutes of actual exercise a day.

by wodenokoto

7/1/2026 at 11:47:22 PM

15 mins of walking or exercise. I did 2 hours of walking 15k steps and it's barely moved my required cardio load to 10 and I need over 200 weekly.

by free652

7/1/2026 at 11:41:57 PM

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".

by SchemaLoad

7/2/2026 at 1:04:53 AM

I walk to the office during warm days, it’s about 30 minutes to get there. I get essentially an hour of walking just by commuting.

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.

by Insanity

7/2/2026 at 12:07:11 AM

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.

by Fricken

7/2/2026 at 12:19:49 AM

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."

by mc3301

7/2/2026 at 12:23:51 AM

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.

by nickjj

7/2/2026 at 12:12:57 AM

At least in China they also have a lot of public parks where they all gather for group exercise with all the other elderly people.

by Gigachad

7/2/2026 at 12:52:37 AM

And the Bay Area as well :)

by mrexroad

7/2/2026 at 2:18:43 AM

I abhor exercise for the sake of it. Instead, I refuse to use a car to do anything but bring my family members to distant medical appointments, and the rare carpool'd vacation. Anything within ~ten miles of home I do with human power, sometimes augmented by stored electrical energy (cargo ebike; I contribute ~1/3 the Wattage). Thus, I get plenty of exercise throughout the day. We used to meet our needs by moving our bodies. Understandably, there are perceived benefits to outsourcing transportation, and very real consequences.

Exception is a morning plank to wake up my core, and sometimes forward bends with a weight. I don't like to do it, but I do feel better afterwards (like with cold showers), so I do it. Harder to do with longer exercise routines, which is why I addressed the cause of my unease rather than slapped on plasters.

by meristohm

7/1/2026 at 11:33:20 PM

I'm confused. The study doesn't mention "Zone 2" even once ...

by Herring

7/2/2026 at 6:06:07 PM

19 subjects? I'll disregard the results. That's not a big enough sample size to be meaningful.

by panda888888

7/2/2026 at 12:27:47 AM

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.

by faangguyindia

7/2/2026 at 1:45:35 AM

Of If I walk 10 km a day on average and do strength trainings 2-3x a week but sit for 10 hours a day - am I sedentary or not?

by b212

7/2/2026 at 8:26:39 AM

What do you think?

by owebmaster

7/2/2026 at 7:50:28 AM

Not sure how one can be healthy and sedentary.

by rienbdj

7/2/2026 at 9:48:51 AM

If I go to the gym 5 times per week but otherwise sit all day, am I considered sedentary?

by Fire-Dragon-DoL

7/2/2026 at 12:26:08 AM

Exercise is the key to a long healthspan.

by tim-tday

7/2/2026 at 3:46:32 AM

I have no idea what 'sedentary' even means. I work on a desk mostly but I also walk 15 - 20 k steps per day because that's just my life and I accomplish most daily tasks (shopping, going to park, coffee, etc walking). Is that sedentary?

by anon291

7/2/2026 at 7:02:15 AM

According to the study:

  Sedentary (SED, n = 9): No regular exercise or elevated heart rate beyond daily tasks. Active (AC, n = 10): ≥150 min/week aerobic exercise for ≥6 months.

I guess if you walk fast and sustain that walking pace for some time, it could count (HR in Zone 2/3). But there's really no replacement for a couple sessions of any sport a week (running, cycling, swimming, tennis, soccer - whatever gets you on your feet and moving).

by zaradvutra

7/2/2026 at 4:29:43 PM

Oh sure I run about 10 miles / week, but that's only like 2 hours max running. I still sit most of the day and have tons of 'sitting' problems. I don't know what everyone else's experience with tech work is, but sports is max 4-5 hours / week, and about 20 hours is spent mostly sitting even with a standing desk. Still have the lower back issues that most sitters have.

by anon291

7/1/2026 at 11:36:15 PM

Seems like a potential use for peptides like Mots-C or SLU-PP-332

by wonderwonder

7/1/2026 at 11:39:30 PM

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).

by jr3592

7/1/2026 at 11:43:33 PM

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.

by SchemaLoad

7/2/2026 at 12:23:15 AM

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.

by topgrain2

7/2/2026 at 6:40:29 PM

exactly.

leave it to a forum mostly populated with software developers to have the most hyperbolic takes.

by jr3592

7/2/2026 at 8:27:55 AM

People in good shape don't hate exercise.

by owebmaster

7/2/2026 at 7:45:55 PM

Plenty of them hate at least some of it!

Source: have spent years at a stretch in pretty great shape. I definitely hated a good amount of what I had to do to achieve and maintain that. Disliked the activity, or simply would rather have been doing something else. But, lots of other stuff (including pretty much all other physical activity) is way more fun if you're at least somewhat in-shape.

by topgrain2

7/1/2026 at 11:44:47 PM

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.

https://duckduckgo.com/?q=desk+stationary+bike

by fhdkweig

7/2/2026 at 12:01:11 AM

they make walking pads as well for the desk; I've never used one but have seen some people who seem happy with them

by wonderwonder

7/2/2026 at 12:47:02 AM

I have a coworker across the country with one. The level of walking that is compatible with an actual conversation on a video call is: slow stroll.

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.

by shermantanktop

7/2/2026 at 5:07:08 AM

This study and most similar do not take into account bone density, this is a concern for women who have to actively build this up early in life to have a reserve (to account for the continual decline after about age 25 that is worse for women) to stave off osteoporosis - as well as continually work on maintenance after that with weight bearing/resistance exercise and diet. At least this is what I learned from my exercise and physiology textbook, the best antidote is building up of bone density in a woman's younger years and I doubt there's research into a substitute for that.

by stevenwoo

7/1/2026 at 11:46:49 PM

[dead]

by DeluluDon

7/2/2026 at 3:58:27 AM

Our mitochondria process the total of our energy needs every day, while exercise adds, percentagewise, only fractional additional energy need.

do you think mitochondria notice the difference? I don't.

If I cut my caloric intake, I drop weight like nobody's business, and that's all thanks to my mitochondria at their place in the chain. It's the same thing my mitochondria are doing when I overeat and put on weight.

by fsckboy

7/2/2026 at 4:39:50 AM

If you live paycheck to paycheck and then get a 25% salary increase, if everything else stays the same, in a year you have already saved 300% worth of your original salary vs 0%.

That is even with your unwarranted assumption that all energy use is the same and doesn't cause different adaptations. This kind of simplicity is just not happening in biology.

by esailija

7/2/2026 at 7:33:51 AM

Exactly, this is called a marginal effect and it's very relevant for our bodies which basically need their homeostasis disrupted to be prompted to adapt.

by Tarq0n

7/2/2026 at 5:49:42 PM

marginal effects are small, but it's where the integration and feedback add up or even multiply. the claim here is that the mitchondria are paying attention to their own marginal quantities which are quite small; the outsized effects if they are someplace will lie elsewhere. For example, sendentary life will lead to less muscle mass, which means fewer mitochondria overall, but that's not the individual mitochondria "noticing" anything.

by fsckboy

7/1/2026 at 11:22:29 PM

[flagged]

by rustcleaner

7/2/2026 at 1:21:15 AM

[flagged]

by Ozzie-D