Exercise intensity influences body composition in healthy older adults (2025)

https://www.maturitas.org/article/S0378-5122(25)00571-7/fulltext

by bookofjoe • 23 days ago

207 185 23 days ago

maturitas.org

myst• 23 days ago

I’m genuinely confused. Was there any doubt before this study that sport makes people healthier?

nayroclade• 23 days ago

That wasn't what this study was investigating.

atwrk• 23 days ago

Well I guess reading the article could ease your confusion. Unsurprisingly it is a bit less generalized than your take.

dgacmu4• 23 days ago

No, but past recommendations for older adults (note that the average age in the study was 72 years old) were towards "gentle" or moderate exercise. We're seeing a shift now towards recommending real weight lifting and higher intensity as we age. ("Real" -> closer to powerlifting in terms of goals and methods)

faangguyindia3• 23 days ago

why is it powerlifting?

general prescription these days for Hypertrophy is 10 sets per muscle group per week 0-3 RIR.

fedeb953• 22 days ago

read the study more carefully if you think it encourages powerlifting for the elders.

dev_tty01• 22 days ago

It says nothing about weightlifting. The high intensity training is on a treadmill. Also, "changes were small and not clinically meaningful compared with exercise of lower intensity and considering measurement error." The study is really not noteworthy and certainly not a basis for changing any population wide recommendations.

mDyJzDPmBdG• 23 days ago

There was plenty of obvious, common sense assumptions that didn't hold at all when methodically tested, like sugar rush in children. And this specific type of studies tries to find a sweet spot between benefits and effort taken. Some results were unexpected, If I recall correctly on found that having to take three flights of stairs daily outperformed many exercise regimes designed for elderly.

ehnto3• 23 days ago

I have met people who figured, because they don't excercise they don't wear their body out, so their joints etc. will last longer. Same for injury, no sport no injury, that must be good!

lukan2• 23 days ago

In a way this is right with high intense/extreme sport. (I did Thai Boxing in my youth, but stopped at some point)

But it is very wrong otherwise, joints for example will suffer if not moved. Blood will only flow into all the areas of the joints if they are moved. And if you don't move, your muscles will be gone and without muscles to hold your joints, loss of stability, great risk of injury, etc.

arnejenssen2• 23 days ago

Charlie Munger thought of exercise as adding mileage to the car.

ksaj• 23 days ago

Donald Trump is one who also believes this. Apparently he believes you only have so many heartbeats, and so you should avoid increasing your pulse.

arnejenssen2• 23 days ago

I got codex to count my total heartbeats from my Garmin data. For four random days the counts were 72.252, 73.823, 68.922, 70.991.

According to google: "typical range for total heartbeats is 86,400 to 115,200 beats per day"

I run every day which would add a lot of beats, but my resting HR is 36 (pushed down by exercise i presume) with a daily average of 50 BPM. So in total a trained person may spend less of their heart beats.

ButlerianJihad• 23 days ago

Sports and exercise are definitely beneficial, but any sort of activity presents a risk of injury.

If people work out, or play sports, without knowing proper form, without using protection or precautions, they'll get injured and then worse off than before. Realistically, manual laborers should be in real good shape, but often their jobs are so low-wage, and they're so interchangeable, that safety precautions are ignored and must be regulated/enforced.

I took up roller skating and was rewarded with a broken leg. I took up gym exercise and was repaid with a hernia. Both required surgery. No regrets! Only wished I could've better understood how to exercise safely!

I once encountered a FB group that was for people to discuss "sports injuries sustained while we were in bed" and I could totally relate, having done weird stuff to my shoulder overnight, rather than pitching a baseball game...

xtiansimon• 23 days ago

“High-intensity training reduced fat and maintained lean mass […] though changes were small and not clinically meaningful compared with exercise of lower intensity…”

High intensity does border on leading to injury — just making the wrong move — and you’re back to zero intensity?

baxtr• 23 days ago

Really depends on how you define high-intensity.

To build muscle, you need to push yourself to a limit. You can reduce the weight and increase the repetitions. This approach is just as effective and lowers the risk of injury.

kakacik2• 23 days ago

This is what I do. When I was beginning with weight training, I followed other's recommendations back then and pushed hard. Had quite often minor issues or injuries in the joints which set me back for weeks or even months, my tendons seem to be my weak spot and it does get worse with age, both limits and recovery.

Lowered the load, increased repetitions and basically nothing for a decade. I can still go almost to the failure, I don't even want to reach it since I don't care about that extra bit. Squats or deadlifts are hard even when not at limits, one feels used body parts for a day or two.

I still add cardio on top of that, its just basic logic of moving around a lot is very good for the body, even if effects are not immediately obvious.

criddell• 23 days ago

Maybe with older adults the baseline goal should be to merely maintain or slow the loss of the muscle, mobility, and cardiovascular capacity they already have? It's not realistic for a 50 year old to think they could build muscle year-after-year for the next 30 years.

ryandvm• 23 days ago

No joke. I go to the gym a couple times a week so that I'll maintain mobility and won't injure myself as I age - unfortunately 80% of my injuries come from the gym.

pjsmith404• 23 days ago

If most of your injuries come from the gym, I recommend you get a trainer.

mrweasel2• 23 days ago

80% of my injuries occurred while sleeping, which seems very weird.

toasty228• 23 days ago

Lift less weight then, there is no reason to get injured in the gym if you have a normal body, proper form and lift reasonable weight. From an health point of view it's better to squat/deadlift a mere 60kg safely than trying to go for 200kg+ and snap a disk for absolutely no reason. 100% of my injuries are gym related, because I threw my back exactly once, and since then I lift reasonable weights and focus on proper execution/form

Some people believe "high intensity" means lifting as much as possible as fast as possible, I'd say more reps and deliberately slow movements are as intense for the purpose of staying in shape/healthy.

Most body weight exercises are virtually impossible to fuck up to the point of injury, done properly they'll keep you fitter than 99% of the population

Aurornis2• 23 days ago

This is highly unusual. You shouldn’t be injuring yourself that frequently at the gym, especially if your goal Is just to maintain mobility and basic muscle mass as you age.

This is such a strange thing to hear, as someone who also has gone to the gym a couple times per week for my life with a lot of different gym buddies.

I would suggest considering a reset of your gym routine and gym knowledge, possibly with the help of a physical therapist to see what you’re doing wrong.

If you’re going to one of those gyms that encourage dumb things like doing heavy lifts in a timed competition format or other bad ideas that were trendy in the 2010s, I really recommend getting out of those environments.

nathan_compton• 23 days ago

There are plenty of high intensity activities with low risk of injury. Rowing and swimming come to mind.

I think the bigger problem is that, as far as I can tell, very few people have the appropriate personality type for high intensity exercise. Most people seem to experience it just as pointless discomfort.

mzhaase• 23 days ago

This is specifically cardio. High intensity interval training can be safe, for example, air bike, battle ropes, etc. High intensity running does have higher injury risk.

SecretDreams• 23 days ago

Everyone just needs to play soccer and avoid the 50/50s if you're an adult that wants to be pain free the next day.

I love me some adult coed soccer. And it can be very high intensity intermittently if you feel like it.

netbioserror• 23 days ago

Calisthenics is a really easy way to push intensity at basically 0 risk of injury. They're all compound and depending on the variation could require high reps, but between push ups, pull-ups, squats, their numerous variations, and accessory work, I would challenge anyone to actually injure themselves while also being able to push to true technical failure.

torben-friis• 23 days ago

It is very possible to injure yourself with calisthenics. Shoulder impingement or tendinitis from pullups with too much intensity/bad form for example. Weight is weight.

wiredfool• 23 days ago

From my son's experience in calisthenics and looking around at the group he sometimes trains with, there are definitely a lot of overload/overuse injuries, at a range from just needing rest to bicep tears.

mapotofu• 23 days ago

This is not good advice and please remove the “basically 0 risk of injury” wording. Mobility is a limiting factor and poor body positioning WILL result in injury. Barbells are safe, progressively overloadable, and learning to move them is a straight line is what most people need to do before a lot of calisthenics training. Most people can’t even do 1 pull up.

superhuzza• 23 days ago

Lots of overuse injuries in calisthenics:

https://www.tandfonline.com/doi/full/10.2147/OAJSM.S394044

onemoresoop2• 22 days ago

Poor form is possible with calisthenics and that leads to injuries or other problems.

busymom03• 23 days ago

In my experience, there's a middle ground. Don't go for 1 to 3 rep maxes. Go for 4-6 rep maxes for a set and then follow it by set to failure in the 8-12 rep range. That gives a good mix of both intensity and volume while still reducing risks of injury as the weights are heavy but not crazy heavy to compromise form.

vmg12• 23 days ago

You just need to build back up to high intensity training over time by consistently exercising and pushing yourself. Injury comes from pushing yourself too hard too soon. Unless you are approaching 50 (and even then) you can recover most of your fitness from your early 20s.

alistairSH2• 23 days ago

High intensity does border on leading to injury

Where are you getting this? The study was about various intensities of cardio - I didn't see it noted, but I'm guessing the high- and medium-intensity groups were on a treadmill, elliptical, or similar. Pretty small chance of injury for the durations they mention, especially as the subjects were monitored while exercising.

And I'm not really surprised by the study - building lean muscle mass takes resistance training, which wasn't part of the study. The study results appear to be inline with what was common knowledge/experience.

And if you're injuring yourself regularly during weight training or other gym activities, I'd suggest you might hire a good coach/trainer for guidance and programming, because that shouldn't happen either.

yodsanklai2• 23 days ago

And if you're injuring yourself regularly during weight training or other gym activities, I'd suggest you might hire a good coach/trainer for guidance and programming, because that shouldn't happen either.

After a certain age, it's difficult to train somewhat intensely without risking injury. You can always find some exercises that work and maintain a physical activity, but this may not be enough to maintain your muscle mass or your stamina.

Etheryte2• 23 days ago

There is no correlation between exercise intensity and likelihood of injury, this is nonsense. You could e.g. just as well make one wrong move when going for a one rep max.

robotresearcher2• 22 days ago

Going for one rep max is intense. If it weren't, you could get a better max.

sghiassy• 23 days ago

“though changes were small and not clinically meaningful compared with exercise of lower intensity and considering measurement error”

m3kw92• 23 days ago

So the the research is inconclusive?

ryan_n• 23 days ago

Just read the study... It was not inconclusive, they found that HIIT was the most effective level of exercise intensity to improve body composition in the ages of people that were studied. It just wasn't a meaningful improvement over medium intensity.

That is a conclusion.

bluGill7• 23 days ago

They measured body composition. Is that your goal? Remember this is for 70 year olds (and a small sample size), even if you got to the ideal 70 year old body, you won't look that good naked - which is all body composition is directly good for. My guess is you care more about health (you should break this down into more details of what health means) and long life.

Body composition is a factor in health and long life. However there are many confounding factors if that is your goal and so you cannot draw any conclusions unless the sample size is very large, and the study runs over a very long time. Thus we get a lot of small studies that study something easy and hope that this is a good proxy for what we really care about. Sometimes science eventually figures the proxy is good, sometimes not, but often we still don't know. (meta studies have been really helpful here)

Large sample sizes are very expensive to study, a grad student without large grants can study 50-100[1] people alone, which makes the study cheap enough that they can do it. This was a 6 month study, again making it something a grad student could do leaving plenty of time to then write the paper and get it published. (Each subject was studied for 6 months, I'm not clear if they were all studied at once, or if different subjects had different start/end dates). All respect for the grad students who do this - despite all the problems I've pointed out[2], they still did a lot of work.

[1] I've never been a grad student, much less one in a field where you would study this. The 50-100 number feels right in my uneducated opinion, but if someone with more knowledge says something I accept their correction in advance.

[2] I wonder what other problems someone in this field could point out.

hasudon7171• 23 days ago

I think this results vary depending on whether or not a person exercises regularly. After just six months of training, older adults who do not exercise regularly may see significant changes, but those who exercise regularly are likely to see only minor changes.

Systemerror7A69• 23 days ago

I think it's important to note that this study, at least to my understanding, compared cardio training - not weightlifting or resistance training. Participants did 3 weekly sessions of either low intensity, moderate treadmill excercise or HIIT ( 4-min @ 85–95%, 3min 60-70% ).

I get the feeling some commenters here are misunderstanding this as a lot of the discussions seems to center about weightlifting.

Additionally from what I understood the biggest difference was that the HIIT group lost less muscle while fat loss was roughly the same.

bitexploder5• 23 days ago

This study is completely unsurprising to me having read a lot of fitness studies over the years. Work muscles harder, muscles get stronger. That is how hormesis goes. The fat loss is simple energy expenditure. You are still producing roughly the same work as someone doing more steady state work. Only effect that might come up is post exercise metabolism elevation but that effect is relatively small and probably present for both groups.

ralferoo3• 22 days ago

The fat loss is simple energy expenditure.

But it's not, unless there is a calorie deficit.

If you do aerobic exercise, almost all the energy comes from burning fat. Because your body will have used very little glucose, you're unlikely to feel particularly hungry after that exercise.

If you do anaerobic exercise, almost all the energy comes from glycogen stores. Your body will crave carbohydrates immediately after exercise, and only resort to glucogenesis burning fat if you don't fuel enough afterwards.

There's a significantly higher risk of over-consumption after doing anerobic exercise and aerobic exercise because your body wants to replace the glycogen that got used up.

IncreasePosts• 22 days ago

I would have thought the fat loss comes from hormonal changes, not merely the energy used during exercise.

thesz2• 22 days ago

HIIT is a borderline strength training.

Consider Tabata protocol.

It is supermaximal effort protocol, participants are required to exert maximum effort repeatedly.

The duration of active phase of Tabata is 20 seconds, half of approximately 40 seconds after which maximum performance (power output) drops significantly, because body switches to a different energy system.

In my experience, Tabata squats are done in range of 16-21 per 20 seconds of active phase. So, basically, Tabata squats are equal to somewhat less than 8 sets of 16-20 repetitions done close to failure. The failure usually come after first active phase, so that's why there are "somewhat less than 8 sets." I personally define failure as breakage of exercise form or exercise pace, and this is what I and others experience in Tabata squats.

And you know what? If you go close to failure, muscle mass and strength grow in the range of 5 to 35 repetitions [1].

[1] https://www.youtube.com/watch?v=dN_c4sQwfTI

Other HIIT protocols are similar. For example, 3 one-minute-active-phase-one-minute-rest supermaximal protocol also leans close to "3 sets of 35 repetitions done to failure" - squats' pace noticeably quickly deteriorate to 1 squat in two seconds.

alfiedotwtf• 22 days ago

So that’s for building muscle, but what about if you wanted to lose a few kilos and increase endurance for long distance running? What would be the way to go to optimise your time?

storus• 22 days ago

Tabata is the craziest workout ever, with Tabata sprints I couldn't feel my legs 3 minutes in and after 4 minutes all I could do was to vomit while shaking on the ground. 7-minute workout with as many reps as possible (even if not in perfect form) helped more overall.

nubg• 22 days ago

can you tldr me if weightlighting will put me roughly in the "hiit" group discussed in the paper, and give me its benefits?

Schiendelman• 22 days ago

No, you also need cardio. Even if your heart rate goes up while lifting, it's sustained cardio that really improves your cardiovascular health, keeping your heart rate up in zone 2+ for 45+ minutes at a time a few times a week.

lambdasquirrel• 22 days ago

Also worth noting that not all muscle mass is the same. Too many people read these things and lacking context, they get swindled one way and then another.

javier_e06• 23 days ago

Some move all their lives and keep adapting their movements as their age. Others did not move much through the lives and when they hit 60s and they start loosing the mobility, doctors suggest for them to move more, if anything. If you never hiked and you start hiking in your 60s for health reasons. Pick up short flat trails.

fiveg• 22 days ago

One thing that I think gets looked past in studies like this is the “noob gains” effect. These participants are healthy adults but not highly trained. It’s pretty well known, in cycling at least, that hard interval training is super effective for untrained people or people coming back from a break, but the gains plateau relatively quickly, and the stress of doing this kind of work is hard to sustain for long periods. Another notable thing is that they are doing 45 minute sessions regardless of intensity, in the real world it’s common for lower intensity sessions to be longer, and for those sessions to be a foundation on which higher intensity sessions are carefully added.

bluGill7• 22 days ago

This study followed everyone for 6 months so they probably got past that factor.

pigeonwarz• 22 days ago

I doubt it. In my experience (at least when it comes to lifting), newbie gains last at least a year. Good chance that if they've been untrained all their life (or the majority of it) that phase is gonna last a real long time.

jcdavis• 22 days ago

I've read a looot of physiology studies about running, and the same dynamics hold true there. This is a flaw (IMO) of of the whole "Norwegian 4x4 protocol" you hear parroted around by biohacker/longevity influencer online, of course with 0 nuance or context of the underlying study and its limitations

tryagainian6• 22 days ago

It’s pretty well known, in cycling at least, that hard interval training is super effective for untrained people or people coming back from a break, but the gains plateau relatively quickly, and the stress of doing this kind of work is hard to sustain for long periods.

This is 100% experience with both cycling and running, and something I worked out on my own early on, prior to the advent of smartphones and even talking to anyone who knew anything.

I enjoy sprinting, both running and cycling, but it’s mostly something I do to regain my endurance ability after a break. Two two weeks of high intensity interval training, and then I’m able to sustain moderate intensity jogging for 30+ plus again, or an hour cycling.

lol8675309• 22 days ago

'were small and not meaningful' why is this on the front page of HN?

tryagainian6• 22 days ago

The perennial question.

Well, at least it’s spurred intellectually curious discussion.

shermantanktop• 22 days ago

Is it? What I mostly see is people describing their anecdotal experience and opinions about exercise in general.

I assume that only a few of them are actually in the age group of 65-85, so relevance of personal experience is dubious.

To be fair there are some questioning the study methodology and conclusions.

maerF0x04• 22 days ago

average age 72.0 years, body mass index 25.8

Careful before you assume you'll have the same outcomes. That's a group of people who are already fairly light compared to the American populace, and likely are suffering from sarcopenia of sorts and have low potential to gain much more muscle. (Protein absorption, hormone profile)

Dietary intake was assessed using a 3-day food diary at baseline and analysed for total energy intake (kcal) and macronutrient intake (kcal) by a dietician dietary analysis software (Foodworks, Xyris®, AUS).

So this is both recall + ad libitum. The change could be due to hormone profile, the exercise itself, inadvertent changes in consumption, inadvertent changes in NEAT.

froobius• 22 days ago

Erm that's higher than the healthy BMI range, so not "fairly light". >25 is considered overweight.

jerlam• 22 days ago

It's still lighter than the average American BMI, which is around 29. On average, Americans are classified as overweight.

tryagainian6• 22 days ago

My BMI is 28.7 at 181cm and 94kg at 45.25 years old.

Am I overweight, not far off obesity?

You probably wouldn’t say so if you saw me.

BMI is mostly only a useful metric when it is.

tryagainian6• 22 days ago

NEAT

non-Exercise Activity Thermogenesis?

I’m a bit of a fitness enthusiast, but not enthusiastic enough to have come across all the acronyms.

huijzer• 22 days ago

In other news, water is wet

fedeb953• 22 days ago

The study is conducted on 123 people.

proee3• 22 days ago

So warning about super-high intensity workouts. For a good while I would sprint hard as possible up 8 flights of stairs everyday instead of taking the elevator. I would do this multiple times per day (3,4 sometimes 5) with no warm-up/cool-down . Each time I would try to push for a PR, figuring might as well go for it! One day, after about a year of doing this, I noticed my heart rate at the top felt a little off. I tested with my watch and it said I was in AFIB. I was able to get back to normal sinus rhythm via getting zapped at the ER, but ever since then if I push too hard (usually on longer runs, going all out) I end up back in AFIB. Though it will reset the next morning.

This could be pure coincidence, but I would recommend doing proper warm-up and cool-down before going all out with HIIT. FYI I'm in my 40's.

Bogdanp• 22 days ago

Regardless of the sport you practice, you probably need to be doing some form of periodization. You can’t go for PRs every session because at some point your body stops being able to recover => you get hurt.

JumpCrisscross• 22 days ago

You may want to talk to your doctor about potential exercise-induced cardiac remodeling. Not an expert on this at all. But it’s an injury mode that’s been recently characterized due to sudden deaths among young, seemingly-healthy sprinters.

deeth_starr_v• 22 days ago

Very interesting. I can also get Afib after many years of high intensity exercise

AnimalMuppet• 22 days ago

FYI I'm in my 40's.

Bad news: Age is a risk factor for AFIB. The older you get, the more likely it is to happen.

proee3• 22 days ago

Also a significant increase in AFIB risk for runners. I am doing around 10-20MPW over the last 5 years. Not sure if this is enough training load, but I've had a habit of pushing too hard on my runs as well.

robocat• 22 days ago

PR

= Personal Record

AFIB

= Atrial fibrillation = a type of irregular heart rhythm

HIIT

= High-Intensity Interval Training

proee3• 22 days ago

ER = Emergency Room :-)

lowbloodsugar• 22 days ago

This was all treadmill. I would expect that medium intensity treadmill, combined with weight training, would have same positive results as the “HIT” treadmill group but without feeling like you’re dying or triggering AFib.

yawnxyz2• 22 days ago

Healthy older adults (n = 123, average age 72.0 years, body mass index 25.8 kg/m2) completed three 45-min supervised exercise sessions per week for 6 months. Participants were randomised to treadmill-based moderate-intensity training (n = 45), or high-intensity interval training (n = 41) or a low-intensity active control condition (n = 37), with individualised heart-rate prescription. Dual-energy x-ray absorptiometry was used to quantify body composition at baseline, and at 3 and 6 months.

ok they didn't even include light/moderate weight lifting as another control, so this is a fairly poorly executed study

basically it comapres hiit with treadmill walking in which case yes, it's slightly more useful, but hiit also causes a lot of damage in a lot of ways

fsloth2• 22 days ago

"hiit also causes a lot of damage in a lot of ways"

Oh! I didn't know about this. Are there any references you could quote?

tacon2• 22 days ago

Just ask the orthopedists down the street from any CrossFit box.

Or their journal articles.

jr35923• 22 days ago

"but hiit also causes a lot of damage in a lot of ways"

Please do explain this.

Technically weight lifting (muscle hypertrophy) also causes "damage" but in a controlled an beneficial way.

tdiff• 22 days ago

I would guess they mean hiit can traumatize e.g. joints or cardiovascular system, especially for the elderly.

knappe• 22 days ago

I really think you're being pedantic to the point of detriment. Runner's knee is a very well known condition in, wait for it, runners!

https://www.mayoclinic.org/diseases-conditions/patellofemora...

justradition• 22 days ago

The hyper rationalist cult on HN has created a race to see who will be the first to claim "this is a fairly poorly executed study".

It really impresses the crowd here if you ignore all limitations introduced by reality, and fail to clearly even assert the requirements that would result in an "adequately executed study."

Bonus points if you finish your shallow skepticism by redirecting the conversation in the direction of your original preheld biases.

Double bonus points if you fail to link to a study that both supports that preheld bias and meets your own standards for how studies should be conducted.

danesparza• 22 days ago

light/moderate weight lifting is not "low-intensity active control condition" then?

HSO• 22 days ago

this gets reheated over and over…

look at the study period.

hiit is not sustainable beyond a brief period. by definition you can only do a limited amount of high intensity before you get cooked.

what you really want is periodization and looking over long periods and aggregate volumes

personalityson• 22 days ago

Insulin -- the fat storing hormone. The opposite hormones -- cortisol and adrenaline mobilize fat tissue for burning. Chronic cortisol leads to fat gain because cortisol receptors become desensitized. Spiking cortisol in short bursts is better than long bouts of elevated cortisol.

gcanyon• 22 days ago

Everyone talking about strength training: that’s nice, but it’s not what this study was about. That doesn’t make it a bad study, it just means you’re looking for a different study.

DivingForGold• 22 days ago

... though changes were small and not clinically meaningful compared with exercise of lower intensity and considering measurement error.

Why even share this research ?

leephillips2• 22 days ago

Exactly. I pointed this out in another comment before seeing yours. They admit they found nothing.

leephillips2• 22 days ago

From the Conclusion:

“High-intensity training reduced fat and maintained lean mass in apparently healthy older adults, though changes were small and not clinically meaningful compared with exercise of lower intensity and considering measurement error.”

I didn’t read the whole paper (didn’t see any reason to after seeing this). But the title seems to be contradicted by this conclusion.

tsoukase• 22 days ago

Anaerobic exercise, which typically is done with weightlifting, converts muscles to a huge anabolic gland. Do squats/deadlifts with good technique and reap lifetime benefits. Add aerobic as habit, like use feet/bicycle and stairs at every occasion and you will be fine. First order effects are better shape and stamina, that lead to second order like better cognition, mood and even less cancer.

Exercise intensity influences body composition in healthy older adults (2025)

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