Aerobic exercise can reduce the risk of metastatic cancer in mice: study
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english.tau.ac.il
link to full paper: https://aacrjournals.org/cancerres/article/82/22/4164/710131...
Epidemiologic data from a 20-year prospective study of a large human cohort of
initially cancer-free participants revealed that exercise prior to cancer
initiation had a modest impact on cancer incidence in low metastatic stages
but significantly reduced the likelihood of highly metastatic cancer.
From the article:
The total study population included 2,734 participants; 243 new cancer cases
were recorded during the 20-year follow-up period.
From skimming the article, I can't find any analysis of metastatic disease incidence in the remaining patients? Am I just missing it?
> The human data, obtained from an epidemiological study that monitored 3,000 individuals for about 20 years, indicated 72% less metastatic cancer in participants who reported regular aerobic activity at high intensity, compared to those who did not engage in physical exercise.
"As our focus was on the relationship between exercise and cancer, we used a propensity score of multinomial logistic regression to control for key variables in the diet assessed using a validated questionnaire."
So the 73% figure is drawn from a small number of cases that were significantly weighted. I'd be interested to hear what people who know this field think about this result separate from the mouse/human exercise stuff.
While I respect the need for these longterm survey data collection efforts, I am not sure I would frankly trust that survey to even accurately be able to tease out high-intensity vs low-intensity efforts from people participating in the study.
And the tie-in from the cohort survey results back into the motivation for the mouse study just isn't done at all. I mean out of their 148 patients with SEER scores, they make no mention at all at metastatic disease occurence or even attempt to tie that figure back to exercise intensity . . .
From what I understand after reading the article, it reports three things:
* big fancy result in mice
* measurements of biochemical changes due to exercise in a few humans
* self-reported questionnaire from a population of ~3000 tracked over 20 years, some of whom got cancer
Guessing at mechanisms for stuff we already know.
We know exercise is good for you, we know it reduces the risk of cancer and death from cancer.
Let's throw a dart at a board full of its good-sounding effects and all nod our heads at the idea it probably contributes.
My eyes glazed over but they seemingly only found a result in high Vs low metastatic activity? Not even metastatic Vs not metastatic.
Edit: oops
https://news.ycombinator.com/item?id=30456358
https://news.ycombinator.com/item?id=27756721
https://news.ycombinator.com/item?id=21605643
etc.
> "Our results indicate that unlike fat-burning exercise, which is relatively moderate, it is a high-intensity aerobic activity that helps in cancer prevention," adds Dr. Gepner. "If the optimal intensity range for burning fat is 65-70% of the maximum pulse rate, sugar burning requires 80-85% - even if only for brief intervals."
https://archive.nytimes.com/well.blogs.nytimes.com/2013/05/0...
If your lungs are burning and you're about to collapse after 30 seconds of activity the intensity is about right.
Do 30 seconds high intensity, then 90 seconds low intensity (don't sit down or stand still), repeat 8 times.
Rowing and sprinting works really well.
https://www.cdc.gov/physicalactivity/basics/measuring/heartr...
I’m 180bpm-ish as a 45 year old male, I get that trying to cycle uphill as hard as I can and can sustain it for some minutes.
They say the equation is 220bpm minus your age, so you should be able to go a bit higher.
Maximum heart rate is also sport dependent. For an equivalent level of fitness, maximum cycling HR is often about 10bpm lower than maximum running HR. This is because running engages more muscles and doesn't restrict breathing as much.
(And for what it’s worth, my max heart rate is the same when cycling or running, within a small margin of error. I’ve never thought to ask anyone if it’s the same for them - I will do now!)
Just want to clarify, I mentioned 160-170 bpm as a regular workout I do where I do not feel anywhere near max (I have seen my heart rate get above 190 while running).
I was replying to this:
> For 80-85% of maximum pulse rate...
> If your lungs are burning and you're about to collapse after 30 seconds of activity the intensity is about right.
And saying that going at 160-170 (above 80-85% according to rule of thumb) for a prolonged period of time, I feel none of those symptoms.
https://marathonhandbook.com/how-to-calculate-max-heart-rate...
Note that wearable fitness trackers that use wrist optical heart rate sensors often don't give accurate readings on such tests so it's best to add a chest heart rate sensor.
"Since HRmax varies by individual, the most accurate way of measuring any single person's HRmax is via a cardiac stress test. In this test, a person is subjected to controlled physiologic stress (generally by treadmill or bicycle ergometer) while being monitored by an electrocardiogram (ECG). The intensity of exercise is periodically increased until certain changes in heart function are detected on the ECG monitor, at which point the subject is directed to stop. Typical duration of the test ranges ten to twenty minutes."
https://en.wikipedia.org/wiki/Heart_rate#Maximum_heart_rate
I think it might be dangerous for some people to seek out max heart rate without a doctor present.
Just put on your heart rate monitor, get warmed up, and then sprint as fast as you can until you collapse, most easily done by sprinting uphill. Note your maximum heart rate recorded.
I think watching this Ted might be helpful: https://www.youtube.com/watch?v=Y6U728AZnV0
With up to 45 minutes of daily exercise you see an improvement. After that there is a period where more exercise has negligible impact and only at the extreme upper end to you see a decline. But even people running regular marathons have lower risks than couch potatoes, you need to get really extreme before it’s an issue.
from https://www.runnersworld.com/news/a20806916/excessive-exerci... :
“First, low exercise is a much more prevalent problem for our society than is excessive exercise. Second, the maximal health benefits of exercise typically occur at quite low levels. More exercise may burn more calories and improve athletic performance, but probably does not lead to better health outcomes.
“Three, in keeping with what Ben Levine said in his Circulation Commentary in 2014, I do not believe that we should go overboard to frighten athletes who want to compete in vigorous endurance sports like marathons and triathlons.”
Lavie also pointed out two new exercise studies in JAMA Internal Medicine....
When mortality rates were adjusted for exercise levels, the researchers found the lowest rate among those who exercised about three to five times the amount recommended by federal guidelines (i.e., 150 minutes per week of moderate exercise, or 75 minutes of vigorous exercise like running). However, the increased benefit of working out three to five times more than the guidelines was modest, the researchers wrote.
More importantly to serious runners, there was no evidence of harm at ten or more times the recommended minimum.
Another JAMA Internal Medicine paper looked at mortality rates in relation to moderate vs. vigorous exercise. In other words, what’s the proof for the federal government’s guideline showing vigorous exercise is roughly twice as good per minute as moderate exercise (75 minutes vs. 150 minutes)?
The conclusion, based on an analysis of 204,000 Australians aged 45 to 75: The current federal guidelines likely underestimate the value of vigorous exercise. The Australian results showed an inverse relationship between vigorous exercise and mortality rates.
A swing with good form works your entire body. 100 reps once or twice a day literally takes 2-4 minutes. Do it after hitting start on the microwave.
HIIT isn't necessarily high-impact.
You will think of every excuse known to man to avoid doing it.
Something like 90% approaches what you're talking about, maybe being sustainable for 15 minutes or so, but that 5% makes an enormous difference.
From what I can tell 220-age seems to be a rough population calculation - sort of like BMI.
It is a starting point, but fit individuals increase their max heart rate and should take a stress test.
But it's far less than ideal.
Unfortunately, long, low intensity cardio (zone 2 on the order of 4 hours per week) is also incredibly important for longevity and health. You also ideally should be doing some kind of real strength training (e.g. barbells) for 1-3 hours per week for long term well being. A good maximum strength building program is usually going to require 30-60 minutes 2-3x a week. Muscle mass degradation is one of the most significant factors affecting quality of life in later age. You mitigate this decline by a) maximizing your potential in your youth and b) doing consistent maintenance work in your middle to late age.
Again, something is always going to be better than nothing. Sadly, our current society doesn't really allow for people to get an adequate amount of exercise, at least for many white collar workers with families.
This also seems somewhat related to the fact that we inject an irradiated glucose analog to make certain types of malignancy show up better on a PET scan (re: Warburg effect)
And I don't think you need a 40 minute zone 4 workout. You can probably do intervals in zone 4 with as much recovery as you need over 20 minutes and induce a lot of (beneficial) stress. Interval training is the key to really good fitness, especially on limited time budgets.
Elyptical, rowing machines, stairmasters, all types of weights...
breaks things up and helps to easily get exercise into your schedule.
I am now using specific strengthening exercises from the kneesovertoesguy program to make my lower body more robust. I am not spending a lot of time on this but am seeing encouraging signs where I can engage in more vigorous activities with less warmup and less pain. If you have any pain (other than muscle exertion pain) during exercise, or even joint discomfort, etc, that's a potential road to injury that you have to step back and address. I stopped lifting heavy weights for now while I focus instead on improving my weak spots.
If you get a heart rate monitor and dive into what you're doing even difficult high intensity runs are enjoyable. It's all about expectations and if you go into it thinking
- "I'm going to run at 75% of my max heart rate" you know you're going to be winded, but at the end feel great
- "I'm going on an easy run 60% of max heart rate" you know you'll be able to have a nice conversation along the way and get some good thinking in
etc etc, it's great. Don't start with a heart rate monitor but after a few months it adds a lot of fun for those who like geeking out on numbers and planning.
From what I understand going more in depth requires either maxing out your HR (Steve House describes how you can do this in Training for the New Alpinism - basically sprinting uphill until you collapse, seems really unpleasant) or doing lactate testing in a lab.
After running my first 5k race all-out, I recalculated my training zones based on a max of 205 instead of the 190 that the apps had estimated for me, and things started to make a lot more sense.
Unless you're used to reaching your max HR during exercise - something I don't suggest - it will be painful, but you're not supposed to hold your heart rate at this level for long either, just long enough for the heart rate sensor to register that level.
Also, max heart rate is only useful after you've been running for awhile. If your body hasn't started adapting to the change, MHR doesn't do much and often inaccurate. It's like 1RM in lifting, 1RM is meaningless in beginners as their bodies and central nervous systems haven't learned to fire all the muscles yet.
100%, don’t geek out in the beginning just run at a slow pace until it’s comfortable and several consistent months in tinker around
https://uphillathlete.com/aerobic-training/aerobic-anaerobic...
If you consider distance running, get good shoes. go to the kind of place that puts you in shoes, and videos you running on a treadmill. Some people are biomechanically sound. I'm not. I need a lot of support to keep my ankle in line with the rest of my leg. Get good shoes and replace them when needed.
You can run anywhere, but pay close attention to the surface you're running on. It's very subtle, but running on a concrete sidewalk is different than running on asphalt right next to the sidewalk. try to run on dirt if you can, it's easier on your body. It also takes a while to really get a good sense of what is normal and what is excessive.
Pay attention to your muscles joints and tendons, take rest days, and cut runs short when you need to. I've called to have someone pick me up, because my legs were done. It can take a while to figure out when you're just dealing with normal "running sucks" and when you're actually pushing the red line where you're damaging things.
Definitely agree with pain as well, there is good pain and bad pain and tendon pain is never good pain.
Some cancers are glucose-sensitive which use glucose to grow.
Some cancer patients go on a keto diet instead of/as well as aerobic activity (a keto diet is probably better tolerated than lots of aerobic activity for many cancer patients).
from https://www.sciencedaily.com/releases/2018/01/180126095312.h...
This dependency on sugar distinguishes cancer cells from normal cells and is often used as a treatment option to kill cancer cells. In reality, the results have not been encouraging. Not all cancer cell types are sensitive to the removal of sugar, and even for the cancers that are sensitive, sugar depletion only slows down the rate of cancer progression. The pathways that sensitise cancer cells to sugar deprivation remains poorly understood.When you're in the midst of trying to find your way through a cancer diagnosis, this statement can be incredibly frustrating. It basically turns into a cop out that medical providers use to wave off any discussion or exploration of a topic. And even if it's been proven to be effective, there's some way to slice your specific case such that it wasn't tested in the trial. Oh, you're BRCA positive? Somatic? Platinum resistant? Recurrent? Have or have not undergone this very specific therapy? Well, the trial didn't cover you so its not proven.
I totally understand why, few doctors would likely want to talk about phase of the moon or rubbing crystals...but in the context of cancer treatment, the lack of any clear guidance or recommendation about diet beyond basic USDA recommendations is maddening.
BTW-- Derek Lowe discusses some of this and how cold temperature / brown-fat could be researched to find usefulness to slow cancer: https://www.science.org/content/blog-post/cancer-cold
>> And like any notable differences between tumor cells and regular ones, there have been attempts to exploit this metabolic change for cancer therapy, but that's been difficult to realize. It can be tricky to throw a wrench into glycolysis without messing up energy homeostasis in general, for one thing, and some of the more indirect attempts have not had clinical success. As that last linked paper outlines, even the reasons behind the Warburg effect are not completely clear - the low-oxygen story makes sense, sure, but there are tumors that don't seem to be oxygen-deprived that also show it.
Even if blood sugar level dips during the exercise it comes right back immediately after. Even if you exercise a lot, for majority of the day your blood sugar level should be nominal because nobody can exercise at the effort needed to dip your sugar for very long.
So does this mean cancer cells are so hungry for sugar that they can't survive even a short term dip in sugar availability?
It's not a short-term dip, according to the article:
> "Examining the cells of these organs, we found a rise in the number of glucose receptors during high-intensity aerobic activity - increasing glucose intake and turning the organs into effective energy-consumption machines, very much like the muscles. We assume that this happens because the organs must compete for sugar resources with the muscles, known to burn large quantities of glucose during physical exercise. Consequently, if cancer develops, the fierce competition over glucose reduces the availability of energy that is critical to metastasis."
> "Moreover," she offers, "when a person exercises regularly, this condition becomes permanent: the tissues of internal organs change and become similar to muscle tissue."
I.e. exercising lots appears to change the makeup of your organs, so they absorb sugar more aggressively _all the time_ and so cancer cells have to develop in a far more sugar-competitive environment.
Doing this only takes 10-20 minutes depending on the length of your warmup, and you'll be working your entire body + cardio + lungs. Just make sure you are using correct form - start slow before going all out.
I run and road bike, but rowing is easily the most efficient way to get into that HR zone quickly. You can do sprints but that's pretty hard on your legs if you aren't an active athlete. Rowing is low impact by comparison.
Not all cancers are glucose-sensitive though.
See the Warburg effect - https://en.wikipedia.org/wiki/Warburg_effect_(oncology)
Exercise seems to fix cancer at the source as indicated by studies showing it dramatically reduces cancer risks. So IMHO restricting carbohydrate is trying to solve the consequence of excess energy through diet whereas exercise solves it at the source.
Exercise causes a variety of changes in the body beyond just altering blood sugar levels. Not all cancers are glucose driven. There is likely a larger grouping of cancers that are facilitated by excess energy in the body (glucose being one form of that), all of which might be helped by exercise. But exercise has many other downstream effects.
Rather than restricting carbs, an approach to requiring a bout of exercise before eating would be much more in line with evidence.
Interestingly, this is a key part of the medical argument for low-carbohydrate diets--that most human diseases are metabolic ones, including cancer, and that modern human diets are at the root of them. One discussion: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6375425/
But even when two people make opposite claims and there's no good consensus either way, trying to assign burden of proof by what seems obvious or reasonable isn't a solution. That just takes you back to two people disagreeing about what is obvious or reasonable, it's just going in circles.
Something you can do instead is put burden of proof on the person deviating from the null hypothesis, because everyone can agree on that. Crucially, the null hypothesis does *not* mean the obvious thing, or the expected thing.
In the case of whether breathing is fundamental and healthy, the null hypothesis is that breathing does absolutely nothing. And of course it's not very hard to reject that one, the null hypothesis is clearly wrong here. If it really is obvious, then you shouldn't have a hard time rejecting it and all is right in the world.
But trying to make a claim that's not so easy to prove, and at the same time trying to escape the burden of proof because it 'seems obvious or at least reasonable' harms your ability to notice when you're wrong. It's dangerous and it's bad epistemology.
Right, but that's because those two are actually the same! The null hypothesis in this case does not directly say whether breathing is good or bad, instead it's a statement about the correlation of breathing to anything at all.
If the null hypothesis is true, then breathing or not breathing doesn't have any effect. So the null hypothesis is not pro-breathing or anti-breathing, the null hypothesis is that it just doesn't matter either way and doesn't correlate with anything (like the person staying alive)
>"Aerobic exercise does not increase the probability of developing metastatic cancer" / "A sedentary lifestyle does not increase the probability of developing metastatic cancer."
With both of those, you can also reformulate them to be a statement about correlation. "What is the correlation between the amount of aerobic exercise that you do and the rate of development of metastatic cancer?"
So the null hypothesis doesn't depend on whether you think exercise is good or bad. That's the subtlety. It just says that everything is neutral and nothing has any effect until proven otherwise.
That doesn't mean the null hypothesis is always what makes sense, or that it's what you should believe in. Obviously breathing keeps you alive, and exercise has a lot of benefits. It's just a way to keep people from disagreeing about what's obvious and who should prove what. The null hypothesis is really dumb, and it only says that anyone who claims they found a real effect, either good or bad, should prove it.
If one person is saying red wine causes cancer, and the other person is saying red wine prevents cancer, then they're both rejecting the null hypothesis, which is that you can't claim red wine correlate with anything until proven otherwise.
And I promise this isn't just for the sake of the argument. There's a real difference between the mindset of trying to claim "X is good" or "X causes cancer" because it seems so obvious that someone else should just prove the opposite instead, and the much more boring idea that if something is actually kind of obvious, then you should be able to measure whether it does anything AT ALL in either direction (good or bad), and force the person actually making the claim to reject the null hypothesis.
As I understand it, correlation is not sufficient to prove causation. "Null hypothesis" is one statistical tool, an abstraction over our understanding of the real world.
Consider the case where all of those infected with disease D die, while 99% of those infected with D and treated with T survive. Further consider that T is widely administered. Clearly, the correlation between being infected and dying is very low although with a deeper understanding we know that D in fact causes death.
Absolutely. The only reason we use it is because most of the other alternatives turned out to be not that great in practice, but it has plenty of limitations to keep in mind (like correlation != causation, but also the common p-hacking that happens, etc etc).
>Clearly, the correlation between being infected and dying is very low although with a deeper understanding we know that D in fact causes death.
That's true, although working back from just the people who die and focusing on those, the method is eventually able to unearth the correlation too. With the people who die, we would naturally start to ask why them? Did they do anything differently than the rest of the population? We'd see pretty quickly that there was one huge factor in common, which is that none of them were using T.
I'll admit that's not enough to say just looking at correlations and trying to disprove nulls is going to be enough in every case. I would just say it's a pretty good starting point when people disagree on a fundamental level about what should be obvious, or who should be proving what. It's really kind of dumb, but in practice in the case of people missing something (most deficiencies, like not having enough vitamin B12, or not having enough thyroid hormone) stats do a pretty good job of noticing that all the people dying mysteriously happen to be missing the same thing. (But of course it misses plenty of things too. And where it gets a lot harder is understanding why any of this happens)
You could do cardiovascular exercise which, in theory, might possibly have a beneficial reduction in personal cancer rates (among many other potential health benefits attributed to persistent exercise). Or you could not do cardio.
Seems like a no-brainer for most people.
So not sure what to say otherwise but this paper is wrong and needs to be challanged.
The paper suggests you need to be at 80-85% max effort to get maximum benefit, the runners I know tend to concentrate on distance and the social aspect (so are running at an effort where they can sustain a conversation), rather than getting to the end of the run as quickly as possible.
Related HN discussion: https://news.ycombinator.com/item?id=30597187