You’ve Been Running at the Wrong Threshold—Here’s the Proof

[00:00:00] I tested my lactate threshold four different ways. Lab test, field test, race data slash online calculators, and my gut from easy runs. And guess what? They all told me something different, but one of them was the absolute truth. Which one do you think it was? In this episode, I’m doing a shootout of sorts, ranking the four most common ways runners estimate their lactate threshold.

[00:00:24] Again, lab test, field test, race data slash online calculators. And my gut from easy runs, and I’ll be doing them from the least accurate and most generic to the most precise, but probably impractical for 90% of runners. I’ll work through what actually worked for me after testing everything. And if you get to the middle, I’ll give you a free download so you can figure out your own lactate threshold and an eight weeks up threshold training plan so you can improve.

[00:00:48] Your own threshold. I’m Daren D Lake Run Coach Sub three hour marathon, our 10 hour Ironman finisher. And for the last 30 years or so, I’ve been experimenting on myself talking to experts and researching how I can get 1% better each day so I can help 10,000 more self-coach runners just like you cut through the internet noise and live a better run life.

[00:01:08] Let’s get into it. What is threshold and why does it matter? For runners, I do a deep dive in a full episode about threshold. You can go to it right up here or in the show notes or video description below. But here’s a quick TLDR lactate threshold is your sustainable running ceiling. The maximum pace you can hold for 45 to 60 minutes without.

[00:01:28] Crashing and burning. It’s crucial because you’re already using it in races from, I’d say 5K, 10 k, definitely to marathon, and it’s your sweet spot for getting faster, efficiently. Think of your muscles like water on a stove. Zone two is a gentle simmer. Threshold is the water bubbling quite a lot and there’s a lot of activity going on and VO two max and anything faster is the water boiling over and then the pasta getting all over the stove and now you got a big mess that you gotta clean up.

[00:01:56] Why it matters. Without knowing your threshold, you’ll either push too hard and bon and hit the wall or run too conservatively. And waste potential and not run your best time. So if threshold is that important, how do you find it without a lab code and a science degree? Here are the four most common ways that runners estimate the threshold.

[00:02:15] I’ll be ranking these from worse to best and using two different scores. One score is accuracy for how close you can get it to your threshold, and the next score is practicality for how easy it is to do as you most likely aren’t pro and you can’t do some of these sort of threshold tests. Alright, coming in at number four of four, again, we’re going backwards.

[00:02:34] Zone two MAF, gut guessing AKA, the Imma individual maximum aerobic threshold formula. IMAT Your gut based on random easy run data. This is a classic starting point for all runners. I started here too. Your run slow. You breathe through your nose, you keep your form clean, your heart rate low. You start now or you know, you go for uh, a hard run.

[00:02:57] You don’t know what really hard runs are ’cause you just started and you’re breathing hard, et cetera, and you’re like, oh, that’s my race base. Uh, you can also use the IMAP method, which was made popular by Mike Trees, who I’ve had co-host episodes with me. You can check some of those out if you go back into the back catalog.

[00:03:12] The idea with all the zone two Mafa, toin, Imma kind of easy running formulas and frameworks. They keep things easy and clean, and your body builds a strong aerobic base. So that’s like 80% easy, 20% hard. It’s great for beginners again, or people rebuilding, but. Here’s a little bit of truth. Took me a while to get it.

[00:03:29] Doesn’t tell you your threshold. It tells you how chill your easy runs are. It’s a different problem, different solution. Pros to using the easy running framework. It’s intuitive, it’s easy to implement, build body awareness. Obviously you also build aerobic base, which you need to run faster, and the cons.

[00:03:46] It’s probably 10 to 20 BPMs off of your true threshold and most people outgrow it fast me, uh, when you want to get really specific and not blow up your next race and not mess up your next race, because usually sometimes at the end of a race you might be like, oh, I had so much more in the tank. I should have gone faster earlier.

[00:04:01] It’s ’cause you really didn’t know exactly how to race it and pace it ’cause you didn’t know your threshold. So I’d score this. At accuracy of four out of 10, practicality, nine outta 10, number three online calculators and or using race time trial or workout data into the online calculators. So this feels lab science-y with algorithms, but realistically has more bro science vibes happening.

[00:04:25] And it’s because it feels like it’s. It’s accurate. So to do it, you just plug your half marathon time into a website. Feed out calculator is what I use, and I did a whole episode on this up here or link below in the video description on the show notes and boom, threshold pace, heart rate zones, race, pacing, et cetera.

[00:04:42] It feels and seems smart, but here’s what’s hiding under the hood. These calculators assume your race was perfectly paced. On a flat course in ideal weather, which it probably wasn’t. Also, these only give you external metrics. So external are the ones that outta control pace, uh, heart rate’s, external and not internal effort.

[00:05:01] And that’s a problem if you’re a self coach runner who trains solo or doesn’t race often ’cause you don’t know what’s going on. Uh, the pros to this, it’s fast, it’s free. And it’s frictionless and the cons. It’s built on assumptions. It can be way off if your race data is messy and wrong. Let’s say you went too hot and heavy.

[00:05:18] Let’s say GPS was off, then that data that you’re putting in is not clean, and then it’s gonna give you a whole bunch of frameworks and times and paces that can be way off. I’m gonna score this with an accuracy of 6.5 outta 10. And a practicality of eight outta 10, here’s a solution to this gap. So at this point you might be thinking, okay, calculator are convenient, but they’re not personalized and zone two formulas and you know, tato stuff, all that.

[00:05:41] They’re just a guess. That’s exactly why I built a free sub threshold plan. Actually, it’s the threshold bundle. It walks you through a simple field test, no lab required. It shows you how to do it. It shows you how to read it. You’ll find your actual threshold and learn how to train just under it, where all the aerobic.

[00:05:57] And slight anaerobic gains will stack up. The link is at the QR code, or you could hit the link below in the video description or in your audio podcast show notes Bonus, you’ll get my weekly five minute newsletter. In your email inbox, you’ll get real world tips on VO two max sprints, long runs, and the mental game, mental strength, mental fitness, all in less time than it takes to warm up.

[00:06:18] You can actually read it. While you’re warming up. All right, let’s get back to the episode. Coming in number two, field testing, 20 minute time trial ish. It’s more like 30 to 40. This is what I use and what I recommend to most runners. You warm up, you run hard for about 20 ish minutes, and you record your average heart rate based on, uh.

[00:06:35] Percentage of those minutes and you multiply that by 0.95 and that’s your threshold. Feels very mathy. But actually it’s not. It’s pretty easy. It’s, it’s not perfect, but it’s surprisingly very accurate. I’ve been doing it for years and I’ve been hearing and seeing from running exercise scientists how accurate this field test actually is compared to lab test.

[00:06:54] And most importantly, you can repeat it. Over and over again. That’s consistency. That’s what we need. So you could retest every month or two and actually track your progress, but the key is you are using your body and not just a formula to get the answer. Pros, it’s pretty accurate if you use a high quality heart rate monitor.

[00:07:11] So get the arms drop or chest strap. Do not use your optical watch base heart rate as those are very, very inaccurate. Um, and again, another pro is that it’s consistent and it’s empowering because you actually are running at race pace. AAN takes effort. And pacing practice. It’s not fun. It’s not fun, like it’s, it’s quite, you’re just like, it’s a bit of that like suffering, but mentally we’ll get tougher from it.

[00:07:36] I’ll score that with accuracy of eight out of 10 and a practicality of nine outta 10. And number one, lactate. Plus VO two max. So if you can get the VO two max test done, we need to lactate. That is a bonus, but just do a lactate test because most places don’t do it. So this is how it works. You’ll go over the protocol, get briefed by the scientist, the guy running the the test.

[00:07:58] You get pricked with sharp needles and you bleed a bit. You run a treadmill with the incline ramped up while a stranger yells faster. Every few minutes. You got this. Go, go, go. And you pay 150 to 250 USD. To suffer, uh, more obviously if it’s Australian or other currencies, it’s legit. You get data on your LT one, so that’s lactate threshold one, which is your aerobic threshold, AKA high zone two.

[00:08:24] So you actually can go, oh, is my MFI tone or whatever. My zone two that I’ve been working on. Accurate of my LT one from the blood test, from the lab test. Uh, and you also get your LT two lactate threshold number two, which is anaerobic threshold, which is usually where you should be racing for about that 45 minutes to an hour.

[00:08:40] Uh, you also, if you want to do the VL two max test the same time like I did, you get your VO two max. You will, in the lactate threshold test, get some numbers around where your zone three, zone four and zone five are. So you can actually incorporate those for VO two macro training. But if you can do the mask at the same time as getting the finger pricked.

[00:08:56] It’s way more accurate data. You’ll also get training suggestions from the expert running the test. And if you’re prepping for a serious race or you just wanna validate what you already know. With proper heart rate zones, boom. You got that from the lactate threshold test. I think it’s perfection. But for most runners, including myself, it’s overkill.

[00:09:15] You don’t need 97% accuracy if you’re not training at 80% consistency. Yes. Think about that. ’cause being consistent in your training is way. Better in the long run than having the test. The pros super precise, uh, best full zone map of everything. The cons, it’s expensive, it’s hard to access at times, and it’s not repeatable easy.

[00:09:35] You have to go to the lab, you have to pay the money, you have to do the test, you have to be rested up, et cetera, et cetera. I’m gonna score this at accuracy, 9.5 outta 10, and the practicality at four, outta 10. So it’s best used to confirm. Not to begin. So yeah, the lab test nailed it. But what if you already had the answer without knowing it when I tried all of them.

[00:09:53] So I tested every single method, lab test, field test, race data, online calculators, and my gut. And you know what surprised me? They all landed within a few BPMs and beats of each other. This the heart rate, I know years of self experimenting, racing, and tracking all my data had calibrated my gut to the point where the lab just confirmed what I already knew.

[00:10:11] That doesn’t happen overnight. But if you’re trained consistently, use good tools and check your ego. You can build the accuracy without ever stepping into a lab. So again, if you want the shortcut to testing and training and thresholds without the lab code, grab the sub-threshold training plan and the whole lactate threshold bundle at the link to QR code here or link below, or in the show notes.

[00:10:32] It includes how to do the field test eight week trending block, uh, to build aerobic power five minute. Weekly newsletter and a whole lot of other good stuff. So now that you know your threshold, how do you actually train it the right way? That’s where tempo runs come in. Everyone’s heard of them, but warning, most people are doing them absolutely wrong.

[00:10:51] Go hear it because I impact the truth about tempo runs and how to use them without frying your system. Or open up the show notes in your podcast players app if you’re listening, peace.