Intensity- how low is too low for aerobic development?

How are you calculating, say 60%? Multiplying by 1.4, or dividing by 0.6?

Power is in watts and speed is in meters per second, so a 0.6 multiplier. Or the 0.6 is a result of dividing LT1 power by CP, for example.

The trivial nature of all those metrics is exactly the reason I’d consider calculating all of them unnecessary. Surely the various time trial results are enough to determine if you’ve improved or not, no?

For example, the VO2Max value you calculate is based on an equation which, presumably, uses your 2400m time. Simply tracking the progress of your 2400m time reveals whether you’ve improved. To then calculate your VO2Max from that 2400m time trial reveals nothing further since the very value is derived from the 2400m result.

In regard to critical speed, you yourself say you can use 2-5 time trials for calculating critical speed, but using more trials (presumably 4-5 instead of 2-3), does not necessarily mean a more accurate critical speed. Yet, you then use FOUR different models to ESTIMATE your critical speed? What!? LOL

I can understand if you like data and are stimulated by processing it through different algorithms, but assuming your intention is strictly functionally driven (i.e. obtaining your critical speed), that appears an over complication of an already overly complicated process.

Are you sure you did not forget your password to your account, lexel? haha

“But the lactate just told me what I already knew by breathing.”

Your Data seemed to confirm that going by feel is the way to go.

That’s precisely where I’m getting to, at this point. All of the testing I’ve done in the past several years has helped me learn how to feel when I’m breathing a certain way or if the ache in my chest means I’m at or too far over threshold. I collect the data know to see if it reflects my RPE.

I pace everything by feel anymore, with some guidance from power. The watch just logs the data.

But you have to practice running at very specific pace ranges if you want to really develop your RPE. And that’s where the data can help.

I track Cooper equation just as a comparison to Apple, Garmin, and measured VO2max. It’s explicitly to compare how good Cooper is to my other estimates. That’s all.

Since my data automatically goes into Golden Cheetah, all I do is open a chart that has 2p, 3p, and extended CP models charted over time. It’s an automatic estimate. WKO, which also is autosync, gives me their PDC model. So with a few clicks, I have 6 years of data available. I can glance and see if todays model estimate is real or not. Or if the model changed because of a breakthrough workout. And to see if the trend of CP is going in the right direction.

Like I said, the data is fun.

Bit of an aside, but where are we with regard to lactate and fatigue? Is it still the hydrogen ions or the inorganic phosphate or are we back to lactate or is it lactic acid?

That’s fair. I certainly wouldn’t disrespect your interest in tracking and comparing those metrics. Perhaps, what would be interesting though is the functional aspect. For instance, do you find your 3 time trials and resulting CS value consistently identify and align with your training paces? Meaning, as an example, have you noticed your 800m and 2400m plateau but your 40 min TT still improve? Perhaps your easy pace range has dropped at a faster rate than your TT paces or has continued to drop while your TT's plateau. Things of that nature.

@letsdoit!

I think this is a bit OTT, in my opinion. You can ask Hard2find, nobody loves data chatting data more than we do, but I don't see the need to do all of those time trials - and this is coming from someone who has/had over 7 years of power data in golden cheetah and I suspect up to a certain point used aerolab more than any human on the planet ha ha

You would be better off (IMO) taking your love for data and putting it into something like extrapolating relationships between training loads and your FTP / CS or whatever you want to call it. You can plan your training and set your goals much better this way than running a load of time trials. I've successfully done all the above for a good decade or so and I've never run or rode a time trial in my life in training. Remember what the F stands for in FTP. Functional. It doesn't all have to be perfect, just you keep whatever procedure you use consistent, even if it's simple. I hope you don't take this as a real bad criticism, I actually admire your enthusiasm for data. I just think you might have gone down a rabbit hole that isn't really going to gain you anything in performance.

I've told Hard2find this story before so he can stop reading now, but I once got into an argument/debate with Coggan about why my FTP isn't my FTP because I didn't use the exact method he carried out. But like, who cares? I can use the FTP I have set to shape my training and data and know how or what I need to do, to improve. If I had set my FTP with his exact protocol, would I have got any faster? Absolutely not. It makes virtually no difference.

For everyone else:

In terms the bigger topic. I don't really think (that I have found) that there is a too slow pace to do your easy runs. I'm at the 16 min barrier for a 5k and recently ran a sub 1:15 HM, I'm still happy to do a lot of my mileage around 8:00 per mile, still sometimes even slower. I see a lot of guys on Strava running way faster than me on their easy days, but not really managing to get enough out of their workouts. I would say almost all runners could slow down a bit and it wouldn't do them any harm, but if I sped up say even 30-45 seconds per mile, in the long term it would probably start to create a ripple effect to the balance of training I've got going at the moment.

I'm certainly interested in the physiology around this debate, as it's without a doubt the most important aspect if someone is looking to improve as efficiently as possibly. But one aspect that is still important is at what pace is running no longer enjoyable? For me, if I run slower than about HM pace + 2 mins, I find the actual act of running to be extremely boring. I find that I'm constantly looking to just "get it over with". And unless someone is paying me to train, and breaking news, no one is, I want to be out there everyday because at a basic level, I'm enjoying my time running.

Trust me, that doesn't involve anything crazy fast on recovery/easy days. But some of the paces others have mentioned just to keep the HR below a certain threshold I just couldn't tolerate on a regular basis. To each their own of course.

Hey, thanks for chiming in.

what you describe about tracking training loads and performance (CP/FTP) I do with the Banister IR model. For both cycling and running. And it’s a nice model that gives reasonable estimates if you give it enough data. That’s where the time trials come in. You don’t like doing them and I do. Functionally no difference in modeling. :)

I find that all these discussions get muddy because there’s no standardized way to characterize performance and everyone has different ranges being quoted for zones.

I follow the method given by Skiba and Clarke (2012) for characterizing performance (CP testing), workout scoring with GOVSS, Banister modeling and future performance forecasts. It gives me an idea of how to develop sensible stress progressions with conservative ramp rates that translate into continuous increases in performance.

What you might think is a rabbit hole is a standard literature review for me. I still have a lot to learn.

But for the sake of the thread, I’m done barfing on it. Hope everyone finds that sweetspot of low intensity that keeps them growing!

I'm interested if you have been using golden cheetah for a while, if you have noticed you are able to index CTL to performance? For instance, in cycling, from a base of 150-160w when totally untrained FTP, each CTL point increase was worth around 1.5w to add to my FTP, no matter however the makeup of the TSS was, to gain the CTL.

Interestingly, for running, I have twice found that I have plateaued around a 18:50 5k at around exactly a CTL of 40 (Daniels training). But each CTL point increase from then, has roughly equaled a 6 second gain in my 5k time (on the same course, so a pretty predictable variable)when reverting to sub threshold training exclusively, with the hunch i had that like cycling, just racking up as much TSS as possible would = huge gains. Which it has, I'm down to a low 16.

Whilst this is slightly off topic, this indexing of CTL is interesting. As it (I believe) shows that there is no "too slow". In fact, my highest ever cycling FTP was on the basis of an absolutely monster 8 weeks of purely very low aerobic effort, it just happened to rack up huge CTL because i was stuck at home with broken bones but i could still sit on a bike and pedal aimlessly for 3+ hours a day on the turbo. Which goes with the theory volume, is all that really matters the rest is the icing on the cake. I don't want to speak directly for Hard2find but either of us I think would be happy to chat or share some data with you, outside of the forum if you are interested.

I’d bet most people here have already found it. The problem is this thing called the learning curve.

Once you’ve passed the period of rapid progress you’re fighting for scraps.

The question is not about ideal easy pace but whether it’s worth it to run another 20-30 miles a week for a little extra pace.

Sure, critical speed and performance modeling has nothing to do with the thread topic, but who doesn’t enjoy a good heist film? Am I right? haha

I can see why you prefer regular time trials if you’re using the Banister Impulse-Response Model (BIRM… not to be confused for Basically Insignificant Running Metric… jk, jk) and/or the Critical Speed Model. I can also appreciate your quest to learn from the research literature, as well as share your methodology and tolerate a little push-back on it. I probably clumsily asked the question in my last post, but what I was getting at returns to your original assertion that,

“So many questions would be solved simply by doing two or three time trials at different distances and establishing critical speed or power. Once you delineate moderate and severe intensities, you can work out the easy to moderate delineation by using an estimated percentage of CS or CP and work from there.”

So, with your assertion, what answers would appear that would otherwise be unattainable or overlooked? Perhaps as sirpoc put it, would the performance result have improved if instead of park run, he’d done 3 time trials every 6 weeks to identify his critical speed and base training paces on that data point?

Sirpoc and Letsdoit! (assuming you’re not lexel, because then you’d already have plenty performance and modeling data through our prior email exchanges haha), I’d certainly be open to an exchange offline. It’s always enjoyable and informative to engage with others who share a common interest!

Alfie, well said. Assigning a fixed value doesn’t scale with any proportionality for runners of varying ability. As a general rule of thumb, sure. But to declare that running slower than 5km pace plus 2 minutes per mile yields no aerobic benefit and that you should limit your easy day volume to whatever distance you can run at that pace… how do you determine that?

In general, I think this topic is hard to resolve. Some, myself included, run quite slow on easy days relative to current fitness. Others, keep the pace closer to the moderate end of easy. Perhaps we are both optimizing by embracing our genetic and psychological predispositions?

It’s not arbitrary. It’s sub threshold, steady state running. And it’s not so slow that you will be running with altered biomechanics. That last point hasn’t been brought up yet but it’s just as important.

5K + 2 is not precise but it gets you in the ballpark. An elite male running 6:xx min easy pace has a ton of anecdotal precedent.

I’m not arguing that volume isn’t important or that those studies showing that volume of easy running is paramount are misleading.*

I’m arguing that volume should be viewed as function of both intensity and duration and that reducing intensity to boost volume is like robbing Peter to pay Paul.

The age grouper is faced with a conundrum. They’d like to run more miles because they’re told that miles make champions (even though that’s not exactly what Lydiard meant when he said that).

But they discover that in order to run more miles they have to REALLY slow down and once again, in Lydiard’s terms, end up putting the cart before the horse.

If today all you can handle is 2 miles at 8:00 pace before this easy run turns into a workout effort for you, so be it. That’s your starting point. That’s aerobic development sans sloppy biomechanics which can predispose you to injury upon returning to hard running.

Repeat that enough times and as fitness improves you will find that those 2 miles becomes 3…4…etc.
You might very well set a PR at a relatively low (for you) easy run mileage. If that occurs, bump your easy run pace. If not, bump your easy run volume until you PR. As Daniels would say, whichever occurs first.

I’d argue that there’s no need to increase easy run volume by more than 60-70 min per session and now we’re talking world class runners. It takes a lot more discipline to keep your volume low than it does to slow down in a world where volume is the badge of honor. If volume is king of any mountain, most runners would be better served by adding volume to their workout days.

*Keep in mind that physiologists and those who design the studies being alluded to are defining “easy” running on their own terms as well.