It's what allows you to go deep — it’s the attack, the surge, the sprint to close a gap, or the push in a time trial to keep your speed up. It’s Anaerobic Capacity and here’s why you need to work on it.
If you’ve done the 1-minute test at the end of our 4DP fitness test, Full Frontal, you know what digging deep into your Anaerobic Capacity feels like. And you can think of your Anaerobic Capacity — your ability to attack, surge, close gaps…and do those things over and over — like a battery. The bigger it is, and the faster you can recharge it, the faster and more powerful you will be. Neal and Mac explain what AC is about, why you need more of it, and which of the sessions in SYSTM will help you get it.
**Learn more:**
https://www.wahoofitness.com/blog/best-nutrition-for-race-day-performance/
**Try the SYSTM Training App free for 14 days.**
https://www.wahoofitness.com/systm/getting-started
Have questions? Please ask us here!
https://wahoox.forum.wahoofitness.com/t/new-knowledge-episode-understanding-4dp-pt-2-anaerobic/20205
Mac Cassin 0:00
Hello, and welcome back to another episode of The Knowledge Podcast by Wahoo. I'm Mac Cassin.
Neal Henderson 0:05
And I'm Neal Henderson. And this is part two of our discussion of 4DP metrics. Today, we are digging deep into the pain locker that is anaerobic capacity. From a technical perspective, anaerobic capacity can be defined as the amount of work that can be done using fast glycolysis, which is the breakdown of carbohydrates without oxygen. Hence, the reason people use the term anaerobic is. Also, it is the ability to repeat high-intensity efforts, especially those that are well above FTP.
Mac Cassin 0:39
So from a slightly less technical perspective, we can kind of describe AC as how large is your high-intensity fuel tank. How quickly can you use that fuel?
Neal Henderson 0:49
Ooh, how about the term flux?
Mac Cassin 0:53
We're being less technical on this part in the flux capacity? Matt?
Neal Henderson 0:56
Come on, man. Wouldn't it fit? So good? Okay, sorry.
Mac Cassin 1:01
And then how well you can refill that tank? Flux in a different direction?
Neal Henderson 1:06
Yeah. Okay. It is still flux, though.
Mac Cassin 1:11
So that's important because the ability to make hard efforts and repeated hard efforts is necessary for many types of racing. There are tons of aspects of cycling, where anaerobic capacity can dramatically impact your ability to perform well. \
Neal Henderson 1:25
Yep. Sometimes I like to think about that anaerobic capacity as being like a battery. And think of different battery sizes that have different capacities to both discharges and then recharge. So that's one way of thinking about anaerobic capacity in a simpler, less technical way,
Mac Cassin 1:44
Like a Tesla Model S versus a golf cart.
Neal Henderson 1:47
Yeah, versus a nine-volt, different anaerobic capacity is there for sure. So some examples of why this is important. Like mountain biking, there are going to be random short efforts that occur repeatedly but randomly throughout a ride for you to just keep your momentum and speed. Even during flat or even climbing sections. On a mountain like you're not just had a super steady, consistent rhythm like you would have maybe on an open road that didn't have any switchbacks. If you have switchbacks on the road, well guess what you have to accelerate as you go through those. So you can dip into that anaerobic capacity a little bit, especially things that are like a criteria or cyclocross race, require a lot of those hard repeated accelerations that dip into anaerobic capacity. And of course, one other track cycling really has high demands on anaerobic capacity. Again, depending on the event, the hour record, maybe not so much, you have a little bit at the standing start in that first half lap getting up to speed. But realistically, most other
Mac Cassin 2:51
I would make the argument that a well-paced our record does not wait no, yeah, if you if you fly and die, then if anyone wants to go back and watch Jack Bobridge is our record, you'll see someone who great pain dips into the anaerobic capacity tank
Unknown Speaker 3:07
Little too soon, and pay a price. Yeah, okay. So generally track, we're going to definitely have a lot of anaerobic capacity with those time trials can also require it. So like an hour record, maybe not so much again when done properly. But a technical time trial that has a lot of corners and accelerations is short, steep hills that you got to punch over, you can't just ride steady and maximize your speed. So you need some anaerobic capacity to excel in those events. Of course, for any other kind of mass start ride that you do, whether it's a race or even just riding with a group, you're going to have a lot of accelerations that occur for you to maintain your position. And so you need some of that anaerobic capacity.
Mac Cassin 3:54
And so you might think, Well, none of those really apply to me or I don't really care that much about riding with the group or sticking with the group. So the real value of improving and maintaining your anaerobic capacity is its role in a hard training session. So with a greater anaerobic capacity, you can complete more heart intervals at the same power or the same number of efforts, but at a higher power. So it's a difference between getting to the last interval of the workout ready to smash it, versus pulling the plug and ending the session early because your tanks are just too empty. So it's important in many racing disciplines, but regardless of discipline, you can, if you can train harder, you'll get better. Exactly, you're
Neal Henderson 4:33
able to create that stimulus if you don't have that capacity. You can't create the stimulus. If you can't create the stimulus, you don't get the response. So that's important. So when we think about testing and anaerobic capacity, there are a few things if you look at textbooks,
Mac Cassin 4:47
Which everyone has lying around, right everyone has a physiology textbook laying around
Neal Henderson 4:54
We might have a few exercise physiology texts with a few different tests, but you know any time we think about anaerobic power, they are going to be high-intensity and fairly painful. But not all of them are effectively looking at the anaerobic capacity, they may be looking at some element of anaerobic power or anaerobic ability, but not that full anaerobic capacity. So all that being said, the most common anaerobic power test that is out there that's been in use for a long time is what's called the Wingate test. And it is an all-out 32nd effort on a biker domitor with a resistance that is set relative to your body weight. And the way the test begins, is you don't have any resistance. And so the person being tested, increases their cadence to peak cadence, and then the resistance just drops like a hammer, and you're sprinting full bogey at the beginning, those first five seconds, you're looking at the peak power. And then you look at the overall average of that 30 seconds, which in Wingate, you'll see people grinding down, the cadence is just dropping, dropping, because that resistance that is dropped at the very beginning is pretty high. And so the other thing that we look at is what we call a rate of fatigue or the change from that peak five-second power to the final five seconds, and looking at the rate of decrease in joules per second. Because you know, power, remember, is a joule per second, so we can look at that rate of decline.
Mac Cassin 6:32
And for those of you who have not done a Wingate test before, I would suggest you keep it that way. They suck. Oh, they're great. In our lab, we had a gal who legitimately just came to a stop with about eight seconds left, and we had to double-check that the weight was correct. And it was she it was just she didn't have that anaerobic capacity.
Neal Henderson 6:54
Yep, just couldn't drive there. And some of it there is a motivation component. This is very intense when you do a wind gate. So we know that. Speaking of intense Mack, the way that we look at anaerobic capacity is a maximal one-minute effort, which occurs at the end of our 4DP test which prior to that one-minute effort includes two five-second Sprint like we talked about in the neuromuscular power episode, a five-minute max effort, which is more for mix aerobic power, a sustained 20-minute power effort, which is more associated with our FTP, especially when it's preceded by that five minute or specifically, I should say, and then we go with this final one minute, really unfaced are over paced as you start very hard. And we have an expectation of a drop in power over the course of one minute.
Mac Cassin 7:49
Yeah, so similar to the wind gate of starting hot and grinding, but in a more white, a full sprint, yeah, you're not starting full bogey at the start it sounds odd to say you're pacing an all-out effort, but there is still a pacing component there. And so when you test that one minute, in the end, you're going to be fatigued. And so the one-minute value for most people is going to be lower than if they were to do just a fresh one-minute effort. And you can look at the difference between those two to get an idea of that recovery ability that you have, for some people there one minute at the end of the test is like 70% of what they could do fresh. For other people. It's almost no difference at all. And those are the people who have a crazy high anaerobic capacity for that recovery recharge, right?
Neal Henderson 8:39
Do they got that recharge skill, they can have a decent-sized bass battery, maybe you know, the battery size is somewhat in way irrelevant here. It's just that ability to recharge it and then hit it again, that's different. And so you can have somebody who doesn't have as big of an anaerobic capacity as an absolute, you know, number of watts, but that they can continually hit it, hit it, hit it, hit it and break somebody off, who has, you know, break away from somebody who has a much higher singular one-off effort. So some different ways of looking at it. So when we think about looking at how we quantify anaerobic capacity and a few different ways, right?
Mac Cassin 9:20
Yeah, so you can do raw watts or watts per kilo, like the other metrics. But because of this unique nature of we're looking at this discharge rate that is battery system, there's a model called w prime that uses kilojoules instead of power. So again, watts are just joules per second. By using kilojoules, we can sort of remove the duration components, so it's not a fixed power for a fixed duration. It allows you to see that over different durations of that short timeframe. How much power could you theoretically do for 30 seconds for one minute for two minutes, kind of if you were to empty that tank over the full time So again, if you can think about your total capacity as the volume of the take, then writing harder drains to take faster? Writing easier below the threshold allows the tank to refill. And the easier you ride, the faster it refills. And there are quite a few ways to estimate w prime, but the most accurate ones require several different maximal efforts of short duration and a very accurate FTP value.
Neal Henderson 10:27
Correct. The w prime balances then a further explanation of that w prime. So what this is, is effectively a running calculation while somebody is writing of what percentage of that w prime starting w prime is still available. So there are some things out there that you know different models that people have run that you can look in analysis after rides to see what that w prime looks like. We use this with our 2016. USA, women's team pursuit squad, in assessing what was going on during the races, the standing start everyone is definitely dipping into that anaerobic capacity a good bit. And then basically during pulls on the front. Because those efforts are so far above FTP, it's dipping, again into that anaerobic work capacity, that w prime, if they're good, if the writer is good at exchanging and getting right to the wheel, and actually riding potentially below FTP or critical power, they're able to reap charge that in aerobic capacity just a little bit. So they have just a little bit more of that top and power to use when they come to the front again.
Mac Cassin 11:41
And that's a really cool way to look at how a team pursuit is written because the goal is essentially, to have everyone bottoming out at the very end.
Neal Henderson 11:49
Yep. And so that four-kilometer mark.
Mac Cassin 11:52
So that's where the tactics actually do come into play, you might think we're just for people trying to go fast. But using each rider, effectively, you can model that quite well with
Neal Henderson 12:01
Yeah, and sometimes, you know, maybe one rider that you're going to actually have them dip deeper earlier, and then get rejected, you know, on purpose before the finish, and then have just the three remaining months. So there are different tactics depending on what your starting skills and capabilities of your athletes are, where they're critical and power, anaerobic capacity, where their FTP is, etc, to be able to maximize the speed for the team. Lots of fun ways of looking at that.
Mac Cassin 12:31
Math is just so awesome.
Neal Henderson 12:33
It is pretty cool back, I do enjoy it. I know I've said that before, but it's true. Not gonna lie. Well, let's talk about training.
Mac Cassin 12:42
I had one building, just yeah, no. Yes. So again, the w prime model is super cool, like most math, but it does have its limitations. In most of the models, that recovery aspect, that refill aspect is essentially a set rate for everyone, which isn't quite true. And the existing models that have been published, don't really take into account fatigue. So that replacement rate, how is that impacted? Five hours into a ride versus two hours into a ride? So there's, there are some limitations to very short sessions. And for a lot of training sessions. It's really handy. But you can't use it as an absolute truth.
Neal Henderson 13:25
It is not absolutely perfect. It's a good approximation of things. But it's not the all end-all for sure. So let's talk about training and anaerobic capacity. NAC what are the keys if you're going to be effectively training, anaerobic capacity?
Mac Cassin 13:40
So the main one is, you know, hard efforts, short, hard efforts, 20 to 60 seconds. And these are maximal or near-maximal efforts. You can, there's no Yeah, it's hard. And it's not a good time, not comfortable. You can also reduce the recovery between efforts that aren't quite as hard. Yep.
Neal Henderson 14:06
Something like half as easy maybe like 15 seconds on with 15 seconds off.
Mac Cassin 14:11
Yep, something just like that. But even more, you can get sessions that don't even have no capacity targets, like rue the day or just some good old Tabata 2010s that because there's such short recovery between you're constantly dipping, trying to recharge, dipping, trying to recharge, dipping, trying to recharge, so you can hit both sides, you can work on the absolute size, with those shorter, really maximal efforts. And you can work on that recharge rate with those repeated efforts. And that even can be something like Fight Club, which is a workout with, you know, you're riding just below threshold, but you have these large spikes and efforts. So you're dipping in and then forcing yourself to try to recover that capacity when you're right up at the threshold. And so you can You can hit it a lot of different ways. It just depends on which aspect of it are you trying to get after
Neal Henderson 15:06
Exactly what's most important for the type of writing that you're doing are racing with, for sure, you know, yeah, you'd have a different type of preparation for somebody who's doing like a kilo type of effort where they come into it fresh and do one all-out effort versus somebody who's doing like a longer criterium or cyclocross race. So, with that, the goal of being a maximal effort is that you don't have to worry about hitting an exact power value for AC efforts. When you do these kinds of training sessions, it always is generally better to use level mode, because, in an erg mode, you're gonna often you know, just kind of hit that limit a little bit sooner, and you're not going to be able to be as effective in completing the task, even if you're a little over the target initially, and then a little under the target towards the end, in, either way, thinking about, you know, the training effort and trying to just put in that relative effort is going to be more important than hitting an absolute target here with anaerobic capacity.
Mac Cassin 16:18
Yeah, these are, right maximal efforts, depending on the day, you might be a little fatigued, but you might be on a really good day. Again, the goal is to fully drain that capacity. And you can only do that by going hard.
Neal Henderson 16:31
Exactly. So when we think about training, another way we can kind of stimulate is to reduce recovery time between those efforts. And, you know, that's kind of part of a progression, if we want to have that increased rate of recovery and being able to dip into the depths of our capacity.
Mac Cassin 16:59
And that turns into, and that leads into the fact that you know, all of these metrics, were having one episode per metric, but they all intertwine quite significantly. And so with those shorter recovery efforts, you know, that's working on maximal aerobic Power Map, which is our topic for the next episode. But you can get them with a session like those two data sessions, you can get a great map stimulus and a great anaerobic capacity stimulus. So to some extent, even if you don't want to train anaerobic capacity, anytime you do, like those vo two intervals, you're getting some of that stimulus.
Neal Henderson 17:38
Exactly. So Mack, what are your favorite sessions for AC work?
Mac Cassin 17:43
The favorite is a tricky one here because I don't actually like any of them. That's not true. The one that is more map-focused, I do like it a lot. But when it comes to, like working on the capacity side of things, I'd probably say the trick, which is some one minute, basically, Max efforts are based on a workout that Neil would have us do outside which was out of the saddle, 30 RPM, you'd count and then you'd sit and still be going Max 30, Count 30 pedal strokes and then stand back up for 20 and then sit down for 20, then Stanford 10 and sit for 10. And it turns into a minute that's when it's rough, but you get you to work on that capacity to the best ability and breaking it up in that way of knowing you're about to stand knowing you're about to say it kinda somehow it makes it easier in your brain instead of
Neal Henderson 18:29
counting is trying to get your mind off of some of the other discomfort that might be going on.
Mac Cassin 18:36
And then in terms of like the recovery aspect, I mean the shovel the Pyramid of Power that's another classic meal workout that I've done out on the road I can't even tell you how many times but it's good it hits a lot of different efforts but it really does highlight that on off and then anything with steady sub-threshold and surges I'm all about this. Yeah. As someone who likes point-doing points races, which is kind of right, and then you sprint every few K.
Neal Henderson 19:08
Yeah, that's a good one, and Fight Club is probably a perfect fit for you on that.
Mac Cassin 19:13
So what are your go twos,
Neal Henderson 19:15
SUFF Idol? It's that short version that you get a bit of that hit into that anaerobic capacity. Half As Easy is just honestly kind of a classic one. I can't say that I love it. But I know it's most effective for that. And by far the top top dog in the anaerobic capacity for me is The Shovel. And good old Pyramid of Power. Yep, that is one that I will always say can provide a whole lot of benefit for anyone who is competing in really any different kinds of cycling type of efforts may Race Across America may be the least. But still, there would be value there for them to do it at least a couple of times a year.
Mac Cassin 20:01
So that is it for this episode on anaerobic capacity tune into the next one where we dive into maximal aerobic power we hope you take some useful information away from this to help you become a better endurance athlete Thank you for listening to The Knowledge Podcast by Wahoo