Cardio fitness is a strong, consistent predictor of morbidity and mortality

Of course, almost no-one adheres to it unless they are already well practiced. It's just deeply ingrained in peoples heads that "only if it's hard or painful it must work". Then people check out of running because it feels like crap, which it does if you always push too hard.

In my opinion, three of the most important rules are:

- slow down! does it feel "too slow"? Great, that's the right speed for most runs

- small steps! feels awkward at first, but is sooo much more efficient and soo much better for your joints

- land on mid- or forefoot (that happens mostly automatically with small steps)

Zone 2 is all about giving the mitochondries a chance to get better at providing a steady energy flow over a long time, mainly by optimizing for burning fat as fuel instead of glucose, avoiding lactate accumulation during the process [3].

In between, in zones 3 & 4, you get a little of both those ends of the spectrum, it's still helpful to a degree, but it's not really optimized: that why it's deemed preferable to spend the bulk of your training time in either your zone 2 or zone 5.

The ideal composition of a training period seems like 90% zone 2 and 10% zone 5, and going for more than 1h of zone 5 per week seems not that interesting. Also, mixing zone 2 and zone 5 in the same training session is not ideal, it's better to stay focused on one thing at at time.

[1] https://peterattiamd.com/category/exercise/high-intensity-zo...

[2] https://peterattiamd.com/category/exercise/vo2-max/

[3] https://peterattiamd.com/category/exercise/aerobic-zone-2-tr...

Your zone 2 speed will change over time. I do most of my training in zone 1 now, and that’s like a 9 minute per mile pace. When I started more than 15 years ago a 9 minute mile felt like death. Patience. This takes a lot of time.

But I don't think that way now. I want to enjoy moving. I want to move playfully and powerfully and efficiently. Exercise until it feels good, not until it feels bad. Love the body you have and take care of it and build it up, rather than hate-exercising to change it.

It's only recently when I learned about Zone 2 training that I came to understand that my training approach has always been backwards. I have always indexed my pace on what has always been a "respectable" mile time, on the assumption that if I run at that pace over and over, eventually I'll be able to go for longer at that pace. And that kind of is true, but not ever to the extent I can keep up with my wife.

Now, I am attempting to approach my running from a "time spent running > speed", and I'm finding that I indeed can run for 40+ minutes straight with no stopping, at a much lower pace than what I had been, and that it is much easier to make progress by running slowly for 40 minutes and gradually increase my pace over time than it is to run quickly for as long as I can and gradually increase the distance.

To explain why harder isn't better: improvement in running comes only a little from muscular strength, so that mental model is bad.

Improvement is primarily based on aerobic development of the cardiovascular system. This is your body's ability to burn mostly-fat with oxygen, deliver the energy (ATP molecules) to muscles, and remove waste products. So you develop more capillaries, your heart gets literally stronger, and this fat-burning pathway gets more efficient.

Going too hard pushes into the anaerobic zone (burning sugar without oxygen). This is good training in some ways, but it can be counterproductive to aerobic development and, most important, it's too hard to do very much volume so the amount of stimulus is limited. By keeping it easy, you can do a higher volume of purely aerobic stimulus.

Then I moved to a bike-friendly country and I started biking all the time. 30 minutes commute one way, 30 minutes back. I live right next to subway but god I hate public transport, and owning a car in this city is a massive headache.

Often I go for a small one-hour ride in the evening. I put on some music, start cycling, and thinking about things. I feel like I get into some kind of trance. When sitting at home I constantly feel "now what now what now what now what", but while cycling, I get into a rhythm and often; not always, but often; I get into a state where my thoughts kinda flow more easily, I can just think about something happy and focus on it, or maybe listen to the music. I live in a low-density area with biking lanes separated from most car traffic, so sometimes I get drunk or high and go cycling, which feels amazing - I have to focus and make it through one intersection, and after that the worst thing that can possibly happen is falling off the bike and getting a few bruises.

Sometimes I go for longer whole-day trips. When I reach the point of complete exhaustion the part of my brain that constantly worries about getting fired or possible WW3 shuts down and it's like being high but without drugs. I plan these trips so that I fight against the wind on my way "there" and then enjoy the help of the wind on my way back which becomes almost efforless. When I come home exhausted, the body experiences relaxation in ways impossible to achieve in other ways.

If you want advice, from my experience: 1. Stationary machines are a scam, 90% of pleasure comes from being outside. 2. Do exercise at a pace "I could keep on going like this forever" and then after an hour "oh not anymore" 3. Get something that keeps you entertained but doesn't require your attention. I don't recommend audiobooks because you need to keep actively listening. I recommend music or radio because if you zone out and stop listening, nothing bad happens. And sometimes try not having anything at all, just watch all the things around you.

But gradually I could hold a lower heart rate while running and now my zone 2 runs are actually faster than my fastest pace I could hold a year ago. Now I enjoy running more than cycling (though my fitness are still probably mostly derived by cycling).

I understood the idea was that by running / cycling mostly in zone 2, you can put in more distance / time as you can recover more easily. It would not be possible to bike 30 hours in a week in zone 3, you would trash yourself.

But for someone like me, biking like 6-8 hours a week, I could easily do a lot of higher intensity, recovery time is not a bottleneck, other obligations in life are. So I really wonder if that still applies if you're only running / biking a few hours per week?

I don't know what the current research says, but I believe jogging is pretty hard on your joints vs running. I'd recommend hiking and fast walking as an alternative if you're looking to transition into running.

I'm the only one among my friends that do this, and I find this to be highly correlated with my running style: Really comfortable pace 7-10km through local forests, only (I tend to do more 10km more than 7km as I like it so much).

I learned this one time when I ran on a threadmill and realized the enormous difference between a slight variation in speed (from 11 to 9 km/h in my case, but the exact numbers don't matter), where I realized with this slight change I could go on indefinitely instead of being quickly exhausted.

Another trick was to focus on the whole body, I had a bad back but ran all my life like this, I now do light deadlift to restore better posture and better range of motion. Bad posture will make your muscle shrink and impede your running too.

As I understand it you can increase vo2max with exactly the type of training you are describing. Long efforts at zone2 can improve vo2 max, but the best improvements involve training at higher zones.

I certainly remember all the stories / headlines "walking is as good as running for cardiovascular health" etc which support the "just train zone 2" approach, but this study seems to me (a layperson) to contradict that.

Can anybody who is more versed in the research chime in? Does this study suggest that HIIT could reduce all cause mortality by improving vo2 max which improves baseline CRF (which is the value this the meta-analysis actually examined)?

If you only run 30 minutes once a week, you won't see as many gains if you do it in zone 2 than zone 3/4. But you also can't run 10h/w zone 4/5, so that's where the zone 2 comes into play. It allows to increase volume without increasing fatigue/risk of injury too much.

I prefer it since it's at a pace where you can easily use your phone/browse the web at the same time.

Walking is also far more practical given that you walk 99% of the time in modern society. Might as well train for the thing you actually functionally do

That's unfortunately not fully how it works. For maximum benefits, you would want to train your aerobic energy system, and to do that without risking injury, zone 2 is the recommended zone. The claim is that pain is gain, but more often than not, pain is your body telling you you are over the limit. By the description of your running experience, you were possibly closer to zone 4.

Of course, the body gets lazy, so you will want to vary your training. Repeat the same type of load, and your body will get efficient operating at that load, meaning your fitness gains will eventually stagnate. That's where the other zones come in.

At the zone 3/4 threshold you start using your anaerobic energy system more, with a stronger build-up of lactic acid as a by-product. Training in that range means your body will get more efficient at faster-paced work. Of course, as you build-up lactic acid, it also means that it is not a pace you can sustain.

But if you do short bursts of exercise at the lower-end of the anaerobic zone, you are actually contributing to making you aerobic energy system more efficient, without over-straining your body too much. And it's exactly the type of exercise variation your body needs to not get into the "lazy" mode.

The traditional way of approaching that is to have a base of zone 2 days (say 80% of your runs), and a few days of zone 3/low 4 days (say 20% of your runs), so that you alternate your loads.

Another approach with similar benefits, especially if you train less often, is the Fartlek approach, developed in Sweden in the 1930s. That's a type of training where you mix-up the load intensity during your runs, in about the same proportions. Fartlek means "speed-play", and it describes the method well. It's generally about approaching your training as you feel it that day. At some point during your run you might decided to increase the pace for a short time. Or you see a small hill that you can decide to attack at a faster pace, thereby changing your training zone. It's all about having fun and making your trainings less boring.

There was this belief in some circles until not that long ago that if you would enter a zone 3 or zone 4 training load during a zone 2 training day, you would mostly destroy the benefits of a "pure" zone 2 training. (Or the other way around, having some zone 2 stretches on zone 3/4 days). That turned out to be nonsense.

All in all, for good progress, and against boredom, Fartlek is the way to go, all the while keeping the bulk of your training in zone 2.

I was "forced" into biking a few years ago (had an injury that prevented running) and had the same problem with the groin. I thought it was a natural thing with biking, but it can actually be quite bad for you in the long run, and it's very fixable! Sitting position and saddle makes a huge difference. Ofc position is the cheaper thing to fix, but saddle is easier.

Go to a bike shop and explain the problem and they'll help you find a saddle that fits you, don't go on with getting your groin numbed.

My goal was strengthening hip (one side has a three plates and a few screws in it) and knee mobility, with losing weight being an extra that I only reach this spring due to diet changes. I did find my Zone 2, where I can chat with a running buddy, and slowly extended the distances I run: Now 5km at 5:40m/km are the norm and 10km is just as possible. Injury-free so far and no ambition for a Marathon. The thing I now have to work at is the cadence which I (at 193cm) had trouble with on the bike as well, but shorter strides at a higher cadence are important to prevent knee injuries.

Whatever you do, I think sticking to it at least three times a week so you look forward for the next run, feel well during it and keep healthy. This is more important than beating records or running insane distances. Those goals are for those with the right genetics.

when i've been running i do similar. though i also do accellerate a bit and slow down, because its... more fun.

- chasing an animal during hunting;

- being chased by a beast;

- playing.

You don't have to really run for good cardio fitnes. In addition to HIIT, now there's IWT (Interval Walking Training), which yields similar results. Also, slow running seems to be more beneficial, too [0].

[0]: https://www.youtube.com/watch?v=z71aHZ4scMs

Its weird though because HIIT is meant to be amazing for your body as well.

I suppose a mixture of both is good, and if I really think about it, we pretty much evolved to do that - low energy wandering to find prey, medium energy to chase prey and exhaust it, brief high intensity to catch up and finish the job. Then you get dinner.

Man, I should go back to the gym.

Or perhaps you don’t fully understand the challenges of establishing causality? Just because an intervention causes an improvement in some bio markers that are associated with lower mortality (unfortunately) does not mean that the intervention will cause lower mortality.

The classic example is vitamin D supplements: Higher vitamin D levels are associated with lower mortality in many medical conditions. Vitamin D supplements increase vitamin D levels. But vitamin D supplements seldom lower mortality.

Why? Probably because vitamin D is produced in the skin when we are in the sun. The more healthy subpopulation of any study will typically spend more time outside, so they will have higher vitamin D levels. But it’s (relative) health that causes higher vitamin D, not the other way around.

The only way to reliably establish causality is really an end-to-end randomized controlled trial (RCT). Stitching together two RCTs is not sufficient.

(Not saying that exercise does not lower mortality BTW, just that it’s complicated, and a study such as this is probably picking up two signals: one causal and one purely correlational.)

I think that in science we have to be extra careful just what we are saying. And saying that this study proves causality would be wrong. I am sure there are other studies that could (do?) prove it but this statistical analysis can only prove correlation.

This is where explaining how causality is established really helps people understand what they are reading better, especially when confronted with something that is not light reading and summarizes a much larger, even heavier read. In other words, instead of saying people don't understand, maybe help people to understand.

There was a ted talk that said bicycle helmet laws would kill more people than save.

The reasoning was preventing people from riding would also prevent increased fitness, and more lives were lost from that than saved from accidents.

EDIT: I think this one: https://www.youtube.com/watch?v=07o-TASvIxY

When it takes 50 years, the statistic probably doesn't hold because you will be dead by then due to the negative influence of smoking on your health.

The other thing is the denominator of vo2 is weight. So losing weight without working out at all will increase vo2

First:

    > Fortunately, this seems relatively simple to change

    > the extra energy I gained from 90-120 minutes of aerobics per day

I found that cardio tended to severely limit my lifting gains if I did anything more than 30 minutes in a week. I stopped entirely and found my lift increased more rapidly.

But that's just me. Just like all the other variables you have - number of sets, number of repetitions, frequency of workouts, rest periods, it's good to try a few options and see which one your body responds to the best.

So I suppose the message needs to be: Both are important.

If you go to a fitness center, some have machines set up for this. Mine used to call it circuit training. At home, if you're using free weights, have enough that you don't waste time changing plates.

It’s tough because I’ve known this for 15 years or so, but when I’m in a hole it somehow seems like it’ll only make things worse. I understand why someone who hasn’t had the experience of feeling better from exercise would see the entire premise as unlikely or absurd.

This is the same problem with CPAP machines - they nominally have a huge efficacy rate, and a rock-bottom rate of people sticking to them, because for a lot of people, they're deeply invasive and uncomfortable, and insurance (in the US) in many cases has stopped paying for them if their obsessive babysitting doesn't swear you've used it 95% of the time, so people just say "hell with it" and stop stressing about, say, not being able to take a hike for a few days of camping because their insurance will stop paying for it.

It all goes back to the fundamental premise of "if your solution requires changing people, you will not succeed."

I started jogging a month or so ago and have definitely seen an improvement in my mental health.

I've had friends able to start exercising a few months in their treatments, when the medication gave them more mental leeway. Before that they were fighting to wake up and properly eat, and do anything really.

(Would be great if there were actually prescribed work-compatible supervised exercise sessions on offer, but AFAIK that's not a thing offered anywhere by any health service)

It feels a bit like the US approach to pain management – instead of massages or physical therapy, some opioid pill is cheaper to prescribe.

In the example you cited, that's 36 hours (!) of runnning in a week: meaning I'd have to run 6 hours a day and only take Sunday off each week before I was officially running too much. And I've noticed I can't run more than 4 days a week anyway, so even that's off limits. 6 hours a day, 6 days a week, even under optimal conditions, wouldn't be something I'd approach even if I was retired.

So practically speaking, "run as much as you can before your body aches stops you" seems like a good rule of thumb.

I'd disagree slightly with your characterization of the author's findings on over-exercising; quoting from the discussion section:

"Our findings do not provide evidence for increased mortality risk with physical activity amounts as high as seven times above the current recommended target range. All cause, CVD and CHD mortality risks were lower at physical activity levels up to approximately 5–7 times the recommended level but the additional reduction in risk of mortality with engagement in activity at levels beyond the recommendations was modest and with increasing uncertainty, as reflected by the wide confidence intervals. Thus based on all of the available studies, we did not identify a higher mortality risk at any level of physical activity above the recommended level, although the lowest point estimate for all cause mortality was approximately 2000 MET min. Our analyses suggest that 10–12 hours of weekly vigorous physical activity cannot be considered harmful to longevity."

My reading is that the authors did not draw any conclusions about increased risks at higher MET levels due to the broad confidence intervals caused by the cancer risk data.

For example, suppose the main impact of exercise on cancer risk were simply the correlation with time spent outdoors in the sun. Then you would expect to see a chart like this. But a conclusion like 'limit running to 3 hours/week, while walking can be up to 12 hours/week' would be totally wrong.

    > 2200 MET-minutes/week is about 3 hours of 8mph running per week

Could it be that it’s just pretty difficult to improve VO2Max in general? Some people’s hearts have to beat harder or they breathe in less than fitter people?

https://old.reddit.com/r/AppleWatch/comments/m5q7yx/cardio_f...

https://old.reddit.com/r/AppleWatch/comments/yte3zd/the_vo2_...

I track my actual VO2Max measurements in Apple Health via a shortcut, and I don't need a daily made-up number messing up my data.

But yes, people don't realize that even just walking at a moderate pace for 20 min 3 times a week provides huge benefits if you are otherwise completely sedentary.

Elsewhere in this topic I mentioned exercise helps me with depression. I’ve speculated that it’s due to simply making my brain work better. Depression often feels like your brain isn’t working. Sometimes it extends to your body. There’s more to it, but what exercise does to me feels a bit like turning the lights up a bit and taking some weights off (mentally and physically).

Note that these are minimums and that there's really no ceiling on getting benefits in the literature so long as you increase volume and intensity in a sustainable way and are eating and sleeping enough to sufficiently recover.

They go to their doctors to know when to start medical interventions.

Even simple waist-to-hip ratio assessement would be a big win for identifying lifestyle concerns, but neither that nor the far more involved VO2Max and DEXA rests are going to become standard unless they becoming a gaiting condition for some celebrated drug or procedure.

And that's as much because of the patient's perspective of what they want from doctors as it is because of the doctors or broader establishment.

Frankly, the vast majority of people don't need fancy tests. The thing is, the healthcare system is not about optimizing health or performance. It's mostly about fixing problems and heading off the most common ones in the easiest ways. If the goal was to optimize, it would be relatively easy for a trained individual to examine most people and tell them to lose weight and exercise more. Hell, you could blindfold the person and their advice would still be right like 80% of the time.

"Excuse me sir, I have you VO2Max and DEXA scan results. It shows your cardiovascular fitness and body fat is problematic. But we already knew that since your BMI is 35 and you told me you don't exercise at all".

Most people have these at home and fail to take meaningful action based on the results.

Go to people who know what they're talking about like the Barbell Medicine podcast for evidence-based fitness recommendations.

> It's also a myth, perpetuated by highly trained athletes that you cannot gain muscle and do cardio, or that you cannot do these things while in a caloric deficit.

I think it's more accurate to describe this in terms of definitions: "gains muscle while in caloric deficit" is possible for the untrained/beginners.

> For the first 2 months, cardio was not part of it.

It's really easy for bad diet decisions to counteract the effects of even a significant amount of cardio; and it's easy to fatigue the body by trying to do too much cardio.

For aiming for calorie deficit, I think it makes sense "do what's least awful out of: reduce calories in food, or add cardio".

> Cardio health is life changing.

I noticed my chess.com rating improved just from improving cardiovascular health.

> started isolated training for muscle hypertrophy utilizing machines for 5+ days a week

My impression as a beginner was that free weights were scary and that there were many exercises you'd have to choose from. (Whereas machines seemed idiot proof). In practice, "squat, deadlift, benchpress" would be a good start. (Or a starting point to read about, anyway).

https://exrx.net/ is an outstanding website that I wish I'd come across sooner.

There are historically lots of things that "seemed obvious" but couldn't hold up under research, which is why we do research. It confirms what you think or maybe it forces you to question what you think. Either way, it is good.

Case and point, there is a rising opinion lately which Trump has promoted that your heart only beats a set, finite number, of beats in a lifetime. Therefore, according to this opposing hypothesis, it makes sense to not perform intense cardiovascular activity throughout your life, because it accelerates your heart hitting that finite limit that it is capable of. This opinion has gained traction in recent years and to some people it "seems obvious" that a faster heartrate might wear it out more quickly, leading to premature death. So to those people, research like this defeats their assumptions and helps them feel more confident about performing exercise because it is research-backed that Cardiovascular Fitness prolongs life.

That's why research is important. Obvious shouldn't stand for anything.

As someone else mentioned, a classic poor man's test of VO2 max is simply to time trial a set amount, such as seeing how far you can run in 10 minutes, and use a calculator. So the same thing with extra steps.

If it's meaningfully improving from year to year, you're improving all the things you care about.

(The best way to improve that is to slowly increase your volume of cardiovascular training over time, with at least 80% being zone 2 work.)

That’s all the watches are doing anyway. Even if you do buy a watch, keep in mind you need to run regular max effort runs to get an accurate value.

You have no idea what his pre-existing medical conditions were.