A lot of comments are claiming this study shows that exercise is good for your health. Though I generally agree with that premise, that is NOT what the results of this study show. The abstract and visual abstract clearly state this.
- The RCT was done only on individuals aged 70-77
- Furthermore the results were not statistically significant at p < 0.05. You can see this in the visual abstract where the 95% CI overlaps with risk ratio = 1.0, where 1.0 means "no difference" between the groups.
Note that the results being non-stat sig does not mean that there was no difference! It means that the difference, if present, was probably too small to detect given the power (number of participants) included in the study. This is important to understand!
Furthermore, in the "Strengths and limitations of this study" they clearly outline some reasons why the results may have been non stat-sig, including:
- "Firstly, participants in the control group had a high level of activity throughout the study, and many exercised using HIIT. This might have affected the study’s ability to detect statistically significant differences between groups."
- "selection bias might have influenced our results, as participants were more active and had better overall health than non-included participants"
Basically, even the "control" group looked like they had a good baseline level of activity, decreasing the activity level difference between that and the two treatment groups.
My takeaway from this study is that in isolation, it doesn't provide much evidence for or against the effect of exercise, but taken together with other studies can be used for evidential value.
The results can also be used to inform future studies. The authors clearly understood this when they stated in the main measure outcome: "An exploratory hypothesis was that HIIT lowers mortality more than MICT."
Firstly, participants in the control group had a high level of activity throughout the study, and many exercised using HIIT.
I absolutely get why they had to use a control group that was decently in shape, otherwise the effect size compared to the sedentary would probably have been so massive as to be comical and uninformative. But…where are they getting 75-year-olds who are doing HIIT? Is Norway full of septuagenarian gym rats and cross-country skiers?
There's also some potential for selection bias in the drop-out rates:
>The numbers of drop-outs after one, three, and five years of follow-up were 76 (19%), 104 (26%), and 132 (33%) in the HIIT group, 58 (15%), 76 (20%) and 101 (26%) in the MICT group, and 61 (8%), 95 (12%), and 156 (20%) in the control group.
In other words, the entire observed effect may be due to HIIT being better at making unhealthy subjects drop out of the study.
- Control: followed the current Norwegian guidelines, which recommend 30 minutes of moderate level physical activity almost every day
- High Intensity Interval Training (HIIT): Generally followed the same program as control, but two of the five sessions were instead a 10 minute warmup, followed by four four-minute intervals, working at 90% max heart rate
- Moderate Intensity Continuous Training (MICT): Generally followed the same program as control, but two of the five sessions were instead a half hour of steady-state exercise, at about 70% max heart rate
Conclusion: There was little to no difference in mortality between the control, HIIT, and MICT groups.
I don't love this study design, because it isn't really testing HIIT (or MICT); it's testing what happens when 40% of your exercise is HIIT (or MICT).
That being said, I think the most important takeaway is that exercise is good for you, and what that exercise looks like is almost completely unimportant. Do what you enjoy and can sustain. If you have ten minutes in the morning, do HIIT. If you have an hour after work and want to get out of the house, go jogging or ride a bike. Anything is better than nothing.
It looks a bit like you’re quoting the conclusion of the study and saying there wasn’t much to conclude. But here is the actual conclusion, copied and pasted, in case people read your version and come away thinking it’s what the study actually concluded.
“This study suggests that combined MICT and HIIT has no effect on all cause mortality compared with recommended physical activity levels. However, we observed a lower all cause mortality trend after HIIT compared with controls and MICT.”
This is a scientific study, presumably posted because the poster believes we can read it and understand it. I’m not sure why it needs to have its conclusion rewritten and then some opinion based advice added.
Although these results are not exactly impressive or compelling (they don't make me want to change my exercise habits), it's reassuring to see researchers go through with publishing underwhelming results, rather than cherry-picking only the interesting results and sitting on the rest, which is a major contributing factor to the crisis of confidence/replication in the social sciences.
Why do you say that the results aren't impressive?
49% reduction in all cause mortality when High intensity interval training is compared to moderate intensity continuous training seems like a very strong result.
Slightly OT: I'm not sure I've ever seen a "Visual Abstract" before and I kind of love it. You can pack way more information into the same space and in a much more digestible format than a purely text abstract.
Two things that stuck out to me after reading the abstract:
* The control group wasn't "no exercise." It was "follow national guidelines for physical activity."
* Median age of study participants was 72.8 years.
Because of this, I'm not sure what this study actually means, other than "grandma should get more exercise." I suppose this is a fine study design, if you specifically want to study senior citizens, but it would be nice to have a much longer-term study on younger people.
Then, there's "Control participants chose to perform more of their physical activity as HIIT than the physical activity undertaken by participants in the MICT group. This meant that the controls achieved an exercise dose at an intensity between the MICT and HIIT groups."
It is perfectly reasonable for the control group to be following standard guidelines. In all medical trials, for example, the control group usually follows the current standard of care. Why does that stick out?
To be clear, the study actually does not show any statistically significant effect of exercise on mortality rate compared to the control group (it shows an improvement, it's just not statistically significant).
The verbatim conclusion they present is:
"This study suggests that combined MICT and HIIT has no effect on all cause mortality compared with recommended physical activity levels. However, we observed a lower all cause mortality trend after HIIT compared with controls and MICT."
I agree that it is a good thing to publish results, even when they are underwhelming or unsurprising.
The main thing that DID surprise me in this study, was that the control group did so much exercise. The effect seen was likely small because it was compared to a control group that did nearly as much exercise as the MICT and HICT groups.
If they repeated this study in the U.S. instead of Norway, I think they would find a bigger effect.
There are many health problems that are mechanical failures. From fractured hip bones to plugged up arteries. Exercise is linked to building muscle and improving blood flow and lowering resting hear Rate. At this point the evidence is more overwhelming than smoking causing cancer. There is no good reason not to exercise. And the easiest exercise is just walking for an hour a day.
I recently watched a BBC Horizon documentary called "The truth about exercise" [1]. It argues that people do not respond the same way to exercise and that even 3 minutes of HIIT per week can make a significant difference.
It features a research by Dr. Jamie Timmons which he presents here[2].
> In line with this, observational studies suggest that exercise has a statistically significant preventive effect on premature all cause mortality with active individuals showing up to a 72% lower risk of premature mortality from all causes compared with inactive individuals
It's probably both. One big predictor of near-term all-cause mortality is the simple question, "can the person comfortably walk for a mile or two at a brisk pace?" (Barring existing mobility issues ofc)
Exercise helps to keep your body less stressed in many ways during its normal day-to-day life. It's good for your immune system, your circulatory system, your digestive system, and even your brain.
A few extra pounds probably won't cut your life short, but chronic heart disease or blood clots or being bedridden in old age definitely can.
I've heard it strenuously claimed from multiple sources that the most important exercises for the elderly are not strength-focused but balance focused.
There's a path from falling to bacterial pneumonia that, as one person put it, means that "The death certificate says the cause of death is pneumonia, but the real cause of death was falling."
I'm fuzzy on the degree to which HIIT would contribute to lower incidence of falling injuries. Meanwhile I have a large pool of anecdata about yoga and taichi, some of it first person (I have, in the last five years, tried very hard to break my own ankle on several occasions, but walked away without even a sprain).
What better way is there to improve balance than to get stronger? Isn't that what improving balance is: Strengthening the musculoskeletal system to support yourself?
This is why the focus on cardio related exercise for the elderly has always confused me. I'd like to see this study done with a basic strength training program instead.
> Control participants chose to perform more of their physical activity as HIIT than the physical activity undertaken by participants in the MICT group.
The implications of allowing the control group to self-select their activities from the guidelines.
I wonder if they would have biased toward the HIIT activities (perceiving them to be better) simply because they were participating in the study. Would the outcome have been different if they were asked to maintain their existing activity levels or somehow replicate the normal activity mix of people following the guidance. Otherwise, it seems more useful to focus on the difference between the HIIT and MICT groups.
Serious questions for people who work on this kind of research or who have done so in the past:
Why do we need this kind of research? Don’t we already have enough to tell us that exercising is good, and that exercising more is probably better?
Ostensibly they were trying to compare the recommended levels of activity with high intensity and medium intensity exercise to see which was better, but would anything really change based on this research? Wouldn’t whatever resources that went toward this research be better put to use by getting more people to exercise instead of studying what’s “best” or whatever this is trying to do?
I understand that doing and publishing research is key to some academic careers (which is questionable in its own right), is that what’s really driving all this? For reference, my view on the role of research in tenured/academic jobs is probably pretty close to the negative viewpoint in this article that was posted on HN a while back:
Discussion [1] indicates that the control group were energised into exercising about as much as the "moderate" (not HIIT) intervention group. This is not an uncommon problem in intervention trials in this area.
Something is better than nothing. More is better than less.
This article's title doesn't really reflect the study. It should be like "5 year all-cause mortality with HIIT vs MICT training in healthy, active adults aged 70+".
For people who didn't read the abstract clearly: for old people, no noticeable differences in health benefits comparing HIIT to MICT to recommended physical activity.
Other studies show that exercise is better than no exercise for old people.
I was about to link a related news article I recently read, but realised it was the same study (done by my alma mater). One thing it also found was that they had a better quality of life, and those training together ended up being fond of the time spent together with new friends.
The 4x4 protocol btw is a staple in Norwegian training, at all levels. 4x4 and "fartlek" and you are soon an elite athlete is almost the mantra.
Wow what a disappointing result. Perhaps underpowered to detect what may only be a small change.
Also perhaps some selection bias in that the participants that sign up for an Exercise Study may already be pretty fit. And we see some of that in the baseline characteristics.
I don't think it was that disappointing. All it says it that the difference between elderly high-intensity and medium-intensity training is very little, and not statistically significant. Same with both combined compared to an elderly control group that is (I think) also physically active.
If you were to compare these groups to physically inactive groups I'm sure you would have seen quite a big difference.
Can someone explain to me what the title of this post means? The most literal way I can interpret it as is "Everyone that trained for five years died". I doubt that is what is really meant.
[+] [-] stygiansonic|5 years ago|reply
- The RCT was done only on individuals aged 70-77
- Furthermore the results were not statistically significant at p < 0.05. You can see this in the visual abstract where the 95% CI overlaps with risk ratio = 1.0, where 1.0 means "no difference" between the groups.
Note that the results being non-stat sig does not mean that there was no difference! It means that the difference, if present, was probably too small to detect given the power (number of participants) included in the study. This is important to understand!
Furthermore, in the "Strengths and limitations of this study" they clearly outline some reasons why the results may have been non stat-sig, including:
- "Firstly, participants in the control group had a high level of activity throughout the study, and many exercised using HIIT. This might have affected the study’s ability to detect statistically significant differences between groups."
- "selection bias might have influenced our results, as participants were more active and had better overall health than non-included participants"
Basically, even the "control" group looked like they had a good baseline level of activity, decreasing the activity level difference between that and the two treatment groups.
My takeaway from this study is that in isolation, it doesn't provide much evidence for or against the effect of exercise, but taken together with other studies can be used for evidential value.
The results can also be used to inform future studies. The authors clearly understood this when they stated in the main measure outcome: "An exploratory hypothesis was that HIIT lowers mortality more than MICT."
[+] [-] perardi|5 years ago|reply
I absolutely get why they had to use a control group that was decently in shape, otherwise the effect size compared to the sedentary would probably have been so massive as to be comical and uninformative. But…where are they getting 75-year-olds who are doing HIIT? Is Norway full of septuagenarian gym rats and cross-country skiers?
[+] [-] zeteo|5 years ago|reply
>The numbers of drop-outs after one, three, and five years of follow-up were 76 (19%), 104 (26%), and 132 (33%) in the HIIT group, 58 (15%), 76 (20%) and 101 (26%) in the MICT group, and 61 (8%), 95 (12%), and 156 (20%) in the control group.
In other words, the entire observed effect may be due to HIIT being better at making unhealthy subjects drop out of the study.
[+] [-] thomascgalvin|5 years ago|reply
- Control: followed the current Norwegian guidelines, which recommend 30 minutes of moderate level physical activity almost every day
- High Intensity Interval Training (HIIT): Generally followed the same program as control, but two of the five sessions were instead a 10 minute warmup, followed by four four-minute intervals, working at 90% max heart rate
- Moderate Intensity Continuous Training (MICT): Generally followed the same program as control, but two of the five sessions were instead a half hour of steady-state exercise, at about 70% max heart rate
Conclusion: There was little to no difference in mortality between the control, HIIT, and MICT groups.
I don't love this study design, because it isn't really testing HIIT (or MICT); it's testing what happens when 40% of your exercise is HIIT (or MICT).
That being said, I think the most important takeaway is that exercise is good for you, and what that exercise looks like is almost completely unimportant. Do what you enjoy and can sustain. If you have ten minutes in the morning, do HIIT. If you have an hour after work and want to get out of the house, go jogging or ride a bike. Anything is better than nothing.
[+] [-] tokamak-teapot|5 years ago|reply
“This study suggests that combined MICT and HIIT has no effect on all cause mortality compared with recommended physical activity levels. However, we observed a lower all cause mortality trend after HIIT compared with controls and MICT.”
This is a scientific study, presumably posted because the poster believes we can read it and understand it. I’m not sure why it needs to have its conclusion rewritten and then some opinion based advice added.
[+] [-] bnjmn|5 years ago|reply
- https://en.wikipedia.org/wiki/Cherry_picking
- https://www.nature.com/news/scientific-method-statistical-er...
- https://fivethirtyeight.com/features/science-isnt-broken/
- etc...
[+] [-] tomerico|5 years ago|reply
[+] [-] scythmic_waves|5 years ago|reply
[+] [-] ckuehne|5 years ago|reply
[+] [-] MFLoon|5 years ago|reply
[+] [-] pmiller2|5 years ago|reply
* The control group wasn't "no exercise." It was "follow national guidelines for physical activity."
* Median age of study participants was 72.8 years.
Because of this, I'm not sure what this study actually means, other than "grandma should get more exercise." I suppose this is a fine study design, if you specifically want to study senior citizens, but it would be nice to have a much longer-term study on younger people.
[+] [-] mcguire|5 years ago|reply
I'm not sure that's really a control group.
[+] [-] conistonwater|5 years ago|reply
[+] [-] unnouinceput|5 years ago|reply
What I wish I'll do: Take above advice.
What I will do actually: file this and never open it again.
[+] [-] pontus|5 years ago|reply
The verbatim conclusion they present is:
"This study suggests that combined MICT and HIIT has no effect on all cause mortality compared with recommended physical activity levels. However, we observed a lower all cause mortality trend after HIIT compared with controls and MICT."
[+] [-] jkhdigital|5 years ago|reply
[+] [-] meigwilym|5 years ago|reply
But it's the gateway drug to more exercise.
[+] [-] krzat|5 years ago|reply
- improved mental state
- protection against covid
- free calories to spend on food or weight loss
- fresh air
- better future health outcomes
- time for podcasts
- new hobby
Overall, I highly recommend trying!
[+] [-] asdffdsa|5 years ago|reply
[+] [-] rossdavidh|5 years ago|reply
[+] [-] jungletime|5 years ago|reply
[+] [-] kyriakos|5 years ago|reply
[+] [-] yamrzou|5 years ago|reply
[1] https://archive.org/details/BBCHorizonCollection512Episodes/...
[2] https://youtu.be/E42TQNWhW3w
[+] [-] kamac|5 years ago|reply
> In line with this, observational studies suggest that exercise has a statistically significant preventive effect on premature all cause mortality with active individuals showing up to a 72% lower risk of premature mortality from all causes compared with inactive individuals
[+] [-] jkhdigital|5 years ago|reply
[+] [-] tgb|5 years ago|reply
[+] [-] chmod600|5 years ago|reply
[+] [-] meekrohprocess|5 years ago|reply
Exercise helps to keep your body less stressed in many ways during its normal day-to-day life. It's good for your immune system, your circulatory system, your digestive system, and even your brain.
A few extra pounds probably won't cut your life short, but chronic heart disease or blood clots or being bedridden in old age definitely can.
[+] [-] czbond|5 years ago|reply
[+] [-] hinkley|5 years ago|reply
There's a path from falling to bacterial pneumonia that, as one person put it, means that "The death certificate says the cause of death is pneumonia, but the real cause of death was falling."
I'm fuzzy on the degree to which HIIT would contribute to lower incidence of falling injuries. Meanwhile I have a large pool of anecdata about yoga and taichi, some of it first person (I have, in the last five years, tried very hard to break my own ankle on several occasions, but walked away without even a sprain).
[+] [-] Spinnaker_|5 years ago|reply
This is why the focus on cardio related exercise for the elderly has always confused me. I'd like to see this study done with a basic strength training program instead.
[+] [-] brlewis|5 years ago|reply
[+] [-] jesterpm|5 years ago|reply
The implications of allowing the control group to self-select their activities from the guidelines.
I wonder if they would have biased toward the HIIT activities (perceiving them to be better) simply because they were participating in the study. Would the outcome have been different if they were asked to maintain their existing activity levels or somehow replicate the normal activity mix of people following the guidance. Otherwise, it seems more useful to focus on the difference between the HIIT and MICT groups.
[+] [-] redelbee|5 years ago|reply
Why do we need this kind of research? Don’t we already have enough to tell us that exercising is good, and that exercising more is probably better?
Ostensibly they were trying to compare the recommended levels of activity with high intensity and medium intensity exercise to see which was better, but would anything really change based on this research? Wouldn’t whatever resources that went toward this research be better put to use by getting more people to exercise instead of studying what’s “best” or whatever this is trying to do?
I understand that doing and publishing research is key to some academic careers (which is questionable in its own right), is that what’s really driving all this? For reference, my view on the role of research in tenured/academic jobs is probably pretty close to the negative viewpoint in this article that was posted on HN a while back:
https://reyammer.io/blog/2020/10/03/the-good-the-bad-and-the...
What am I missing?
[+] [-] explodingman|5 years ago|reply
Something is better than nothing. More is better than less.
[1] (audio and transcript) https://www.abc.net.au/radionational/programs/healthreport/m...
[+] [-] jcoq|5 years ago|reply
[+] [-] binarysolo|5 years ago|reply
Other studies show that exercise is better than no exercise for old people.
Obligatory favorite exercise article: https://www.theonion.com/new-study-finds-running-for-20-minu...
[+] [-] matsemann|5 years ago|reply
The 4x4 protocol btw is a staple in Norwegian training, at all levels. 4x4 and "fartlek" and you are soon an elite athlete is almost the mantra.
[+] [-] joshgel|5 years ago|reply
Also perhaps some selection bias in that the participants that sign up for an Exercise Study may already be pretty fit. And we see some of that in the baseline characteristics.
[+] [-] fwsgonzo|5 years ago|reply
If you were to compare these groups to physically inactive groups I'm sure you would have seen quite a big difference.
[+] [-] jaggirs|5 years ago|reply
[+] [-] ikeboy|5 years ago|reply