When is it appropriate to focus on aerobic capacity?

I’m hoping that the podcast guys see this and it turns into a deep dive but the simple question is:

When should I focus on improving aerobic capacity? I think the easy answer is 95% of the time because cycling is an endurance sport but I’d like to get your guys’ take.

Also, does anyone have an easy and/or straightforward definition of aerobic capacity? We have FRC / Anaerobic Work Capacity to determine our ability to perform above FTP but to anyone’s knowledge is there a good metric for aerobic capacity?

What is the best way to increased aerobic capacity? Competing points of view here: LSD or SST?

I’d really like a deep dive!!

You can use Aerobic Decoupling as a measurement.

Joe Friel says:

aerobic capacity is your ability to use oxygen to produce energy


LSD + HIIT (aka Polarized).

By definition, this is VO2Max. WK04/5 provides good estimates, but obviously you can get lab tested.

It’s a ladder approach from sub-maximal threshold training (endurance/sweet spot/threshold) through lactate clearing (O/U - FTP) to anaerobic (FRC to pMax) with endurance (fat burning) on going throughout. Dozens of great WKO videos (from minutes long to 1hrs 30min/2hrs) to give you the “deep dive” understanding you want. And if that isn’t enough, most of the videos are based on the published research by Dr. Andy Coggan and his fellow researchers (15 such papers have received international recognition).

Again, I will refer you to TP/WKO4 videos. As described, it’s the ladder approach (progressive Time-in-Zone) leading to supercompensation. This applies both submaximal and supra maximal threshold (above FTP). For “dialing in” your performance above threshold (including aerobic capacity/VO2Max), you will want to understand Coggan iLevels. (Several videos to watch including Fatigue Resistance, iLevels and Optimized Intervals, among others).


On what time frame?

Good point, I guess I was meaning more along the lines of similar to how FRC is measured (in kJ). I know in the WKO Power Users FB page there was a guy asking about a completely aerobic version of dFRC and was wondering if anyone knew anything about this.

According to Joe Friel: 2-4 hrs.

Here is Joe Friel on the subject:

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Ah, I think I now have a bettering understanding of your questions [let me know if I am still misunderstanding it]. I think what you are referring to as aerobic capacity question is really what Joe Friel (sports scientists) calls aerobic threshold.

In Joe’s “The Cyclist’s Training Bible” chapter 4, he describes two intensity points: Aerobic Threshold (AeT) and Anaerobic Threshold (AnT). AnT, of course, is similar/identical to Lactate Threshold. [and above this, of course, is Aerobic Capacity [VO2Max].

At rest, you produce approximately 1mmol/Liter of lactate. When it rises to 2.0, sports scientists (as stated by Joe) consider this your aerobic threshold (AeT) and it occurs around an RPE of 3-4. [And, as you know, at approximately 4.0 (for most people) is your lactate/anaerobic threshold.]

As for training your AeT - ability to operate aerobically for long periods of time without accumulating excess lactic acid, there are two limits to doing so - fuel and muscle fatigue.

For fuel, you rely on body fat, so to train conversion of fat to glucose for energy you need to ride LSD (as you mentioned above) - roughly 60% FTP and below. BTW: Joe describes it at 20-40 bpm below AnT.

For muscle fatigue [resistance]: Sweet Spot and Threshold training is great for short term fatigue resistance (e.g. increasing your FTP and TTE). It also has some positive impact on long term (i.e. Stamina). However, to really train Stamina (how flat your PDC tail is), and more specifically, your resistance to muscle fatigue over long durations, requires . . . riding long durations (i.e. you aren’t going to be well prepared to ride double centuries with 15-20kft of climbing by doing 3x15 sweet spot :slight_smile: .)

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Aerobic capacity = VO2 max.

The best measure would be to go out and do an all-out effort for 8 minutes (when Veronique Billat measured velocity@VO2 max - vVO2 – she used a 6min time trial for runners; the non-weight bearing nature of cycling changes the energy dynamics a bit, so 8min is a better number for us to target). Not 5 – that will overestimate your wattage at maximal oxygen uptake.

Doing 3-4 minute intervals at that 8min max effort pace will be very effective VO2 max training.

In a linear periodization structure, you would do these after 8-12 weeks of FTP development. However, there are other approaches to periodization that have riders engage each energy system every 10 days or so. For example, you may be focusing on either FTP or the aerobic threshold, but you do a once every 10 days fartlek ride where you remind your body of your current 8min wattage for some 2-3 minutes chunks, just to keep that system open.

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Great info, but why are these two things decoupled? Why does FTP development not increase VO2 max and vice versa?

FTP work does increase VO2max and vice versa. It’s just a matter of introducing different stimulation to the body so you don’t stagnate. Sometimes you push, sometimes you pull.

Well, all training intensities can elicit VO2 max if done for long enough durations (look up slow component VO2), and FTP training does have a positive effect on VO2 max - it just isn’t the main effect of that intensity level. To quickly elicit VO2 max, and to target the stroke volume and mitochondrial efficiency adaptations, the 3-8min efforts at/near vVO2 (velocity at VO2 max) are the best means of targeting those adaptations. FTP does raise VO2 slightly, and VO2 does raise FTP (I usually get a 5 watt boost after 6-8 weeks of the 3-8 min hard stuff), it’s just that FTP training is better for eliciting FTP increases, and VO2 intervals are better for eliciting VO2 increases.

Seiler likes to show a study (Its on the video of his presentation in France a few years ago) that the highest performances came from the group that did their FTP work before their VO2 work (as opposed to the ones who did the VO2 before the FTP, or the group that mixed the high intensity focus). Coach Chad could get into the deep dive specifics, but it generally yields better results to max out adaptations to FTP work, then do the 6-8 weeks of VO2 intervals to “raise the ceiling.”

Remember that all training intensities are on a continuum, and that no “magic line” has been crossed when you move from one intensity to another (I hate the word “zones”).

Say your FTP duration is 50min (not everyone’s FTP duration is an hour – for some it might be 30min, for others 75min – see Coggan, and the ongoing crap fights on the wattage group about what Coggan meant by “about one hour”). Riding at your FTP for the full limit duration of your FTP will eventually elicit VO2 max – probably during the last 10min of the effort when your breathing is ragged and your whole body is on fire. But, the majority of the duration has been spent on lactate clearance and sustaining that maximal lactate steady state, so that’s were the main training benefits are.

Now, if you sustain a much higher power – say the highest power you can sustain over 4 time 4min on, 4min off, yes, you’ll have to clear lactate, and yes, after a 4-8 week cycle you’ll see an FTP bump, but because you’ve had the throttle down harder you’ve worked the energy demands for short duration effort where lactate rose sharply, even though your pace was steady. You were demanding that your heart pump more blood per stroke, and that your fast-twitch fibers work aerobically to meet a short-term demand, and to burn a lot of glycogen in that 4min time frame. So, that’s where the primary adaptations are.

Rather than getting lost in VO2/FTP/AeT whatever, think of the demands of your race.

Do you have to go really hard for 1 minute? 5 minutes? 10? 20? 60? 360? Train the “go hard” durations you need for your race, and build from the bottom up on the intensity scale. It just works (except when it doesn’t)


That interesting because in the last FastTalk podcast that he did he recommended the 4->8->16 minute protocol where you would think it would be the other way around based on that information.

I’m on board with all that. I’m just thinking about what I want to focus on this off season.

You guys have all brought up great points… where do you see SST fitting into this whole equation? I know the guys have talked about one approach to training (simplistic as it may be) is to do SS and just gradual push your FTP up week over week.

Seiler doesn’t see the 3 x 8min protocol as an interval panacea. It was the most effective for eliciting adaptations in one study – and Seiler has remarked many times that there is a role for all intensity levels during the year.

As for his discussion of the traditional, reversed, and mixed groups with reference to building FTP before peaking VO2, it starts right around the 30min mark.

Colby Pearce advocates doing the work at 90% FTP and then hitting the 95-100% stuff for about 4 weeks right before peaking (he was talking about his preparations for hour records.

As I get older (I’m 52), I find that approach more and more appealing. I’m in no mood to do full-on FTP intervals on a trainer anymore.

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you are correct, the answer is ALWAYS!

How often do you recommend the more aerobic focused workouts? Also, how would you schedule them when also working Threshold?

Thanks :slight_smile: