jsw97
2 hours ago
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
an hour ago
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
an hour ago
> 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.
koolba
4 minutes ago
> 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.
adam_arthur
an hour ago
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
28 minutes ago
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)
econ
a few seconds ago
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.
adam_arthur
23 minutes ago
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.
Schiendelman
8 minutes ago
I challenge you to look for studies. Read a few. There are hundreds on this topic!
strbean
21 minutes ago
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.
chongli
7 minutes ago
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.
Schiendelman
8 minutes ago
It can't, because it isn't training your heart and cardiovascular system.
strbean
a minute ago
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?
faangguyindia
42 minutes ago
>(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
14 minutes ago
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)