[jsw97]

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.

[adam_arthur]

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)

[makeitdouble]

> 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.

[adam_arthur]

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.

[makeitdouble]

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)

[adam_arthur]

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.

[bluecalm]

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.

[Swizec]

> 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

[econ]

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.

[bluecalm]

>>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).

[koolba]

> 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.

[Schiendelman]

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

[faangguyindia]

>(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)

[adam_arthur]

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)

[Jweb_Guru]

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.

[adam_arthur]

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.

[Jweb_Guru]

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.

[adam_arthur]

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.

[IndySun]

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

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

[adam_arthur]

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)

[strbean]

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.

[econ]

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

[chongli]

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.

[strbean]

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)

[DrJokepu]

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.

[econ]

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

[Schiendelman]

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

[strbean]

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?

[Schiendelman]

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.

[econ]

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.

[strbean]

> 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.