What's the "Perfect" VLamax for Zwift Races?

didn’t find anything about what’s “the best” VLamax for efforts like a Zwift Race.
So to speak 40-70min races with short efforts from 1 to 5 minutes with maybe hard short sprints in between. Or to compare to a cyclocross race.
My VLamax is now at about 0.4 and i don’t know if my goal shoud be to in- or decrease it!

Of course FTP and Vo2max should also be as high as possible that’s clear, but i want to know just about VLamax now.

Any suggestions to that?
Thanks guys.

I would say 0.5-0.7 would be optimal for shorts punchy races like zwift. 0.4 is maybe a bit low

So thinking about those 3 pieces to the Zwift race example (40-70 min, 1-5 min short efforts, hard short sprints in between), which one is presenting the biggest gap for you to get the best performance in the race? And what is the race outcome you’re looking for if you were to achieve your best VLamax? I think those two pieces need to be tied together before a number is thrown out, because it can be very different for everyone.

Have you looked at how your AT and VO2 max would change by increasing or decreasing your VLamax? Where do your AT and VO2 max currently stand?

0.4 isn’t a bad place to be with your VLamax in general. Figure out what your gaps are in those races and that will give you the answer you need.

If you’re making it to the line no problem but you’re just unable to hit high peak powers and then hold it long enough, maybe increasing your VLamax would help.

If you’re using a bunch of energy with 1-5 min hard efforts bridging or attacking, is that just too much W’ that you’re tapping into before the end? Lots of areas can help this - is it recovery between efforts, too many efforts, how is the race playing out, what’s the strategy relative to the course location, etc.?

Hy Ryan,
thanks for your answer.
My AT/FTP is about 270W (4w/kg), my VO2max should be around 56ml/min/kg (340W), VLamax is as said 0,4mmol/l/s and FATmax around 190W.

My greatest problem with these zwift races is in the most cases the hard start (first 3-10 minutes depending on the course), and i’m mostly out of power when the main thing (a climb) starts.
My Sprinting Power is not very good, but ok. When i get into a sprint relativly fresh I’m not winning but i’m not as far away from with the first places.

Now i don’t really know how exactly to work and train on these weaknesses. Is the limiting factor my VO2max, or - what i think more - my FTP. So if my FTP would be higher i get mor fresh to a climb or a sprinting finish.

Back to VLamax, I don’t know to which side my VLamax value should go, or if it’s even doesn’t matter that much in my case.


Hi @afitz, thanks for the information.

Right, those first minutes of Zwift races are so hard. They are really meant to sort out the stronger individuals very quickly as that time frame is just long enough that you can go above threshold and dig a massive hole. And that hole is really hard to dig out from if you go too deep.

Is there a race graph that you can share to highlight that struggle?

I think you’re initially leaning toward the right piece of the puzzle - FTP.

And because we’re talking Zwift, we can’t leave out the course specifics and your body weight. Are you a very light rider where you will struggle in a race start on the flats? How well can you draft in the game?

Finally, what’s your warm-up routine like? If you lose your group in the first couple minutes, it’s usually futile to try and chase back on. And what does success look like to you in these races? Certain finishing place/range? Finish as % of winners, etc.?

Exactly, i’m a relatively light rider (67kg), but not as bad in drafting.
But looking on w/kg in game i have to do more absolute watts on the flats than the big guys around me :slight_smile:

I don’t have a special warm-up routine. Mostly i warm up for about 40 minutes just do L1/L2 and some ramp through the zones or even some minutes in tempo zone and 3-5 shorts sprints that’s it. You think there is still potential to get more out of it?

Success in such races for me is not a special place or % of winner to place, just want to do what i can and have fun. But as said i have to use so much power just to get to the crucial places in the race that there is nearly nothing left to do - for example - a good 5minute effort (what i’m normaly not bad in).

So you think the best advice for that problem is to rise my FTP. There should also be potential cause it’s just around 80% of my vo2max power.

Here is a good example of a race where i can’t do anything powerful where the crucial climb starts:

This is quite high and could be difficult to shift higher. Perhaps some solid aerobic capacity work would give you space to grow FTP.

I would agree there is potential for FTP improvement. In that file you can see that you spent over 6 minutes at >96% of HRmax. That’s going to take a while to recover from and probably tap you out for being able to repeat that or do more when the crucial moments start.

Roughly, 4w/kg can get you good performances in Zwift in the B races (not sure which group you currently race), but that’s going to depend on how the races play out, and the specific course. If you’re leading the pack and pushing the pace to shed other riders from the start, you’re probably more like 4.5w/kg or higher for AT.

Ok thanks for the response, then i will try to work on improving my FTP.
Any special suggestions for good workouts? Maybe some Sweet Spot, or even more directly near my Threshold power?
Would be great, thanks!

You’re welcome. Yes, I would suggest starting with the Cycling Interval Training Pathway. This has an assortment of intervals, some high intensity, some threshold, so you might explore some of those threshold workouts. That pathway walks you through the foundation of intervals, how to approach them, etc. and then you could always start with Trevor’s 5x5 workout as a great starting point too.

I also love tempo work, so depending on your timeline, you could do some great work at around 80-87% FTP and then go into sub-threshold as in the examples above. Just be sure you’re recovering and not pushing too hard too soon. This article that Trevor recently published is a great base piece to help out: The Relationship Between Performance Level and Training Stress.

My general recommendation is to select a workout that fits in with your training availability and then run with it for a while. Give it ~6 sessions, see how you do building the fatigue and recovering from it. The 5x5 is an easy one to start with because it’s not a workout that will tank you, but has good effects on the aerobic system and is good at pushing threshold. You can repeat that cycle or progress to something longer like 4x8. Just be aware of the fatigue that’s being built in. I would do that no more than 2x per week.

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Interesting thread, I found myself perfectly described in @afitz intervals.icu graph of a Zwift race (racing in the same ZRL League, B cat, other division) in particular for the effects of first 5 mins hard starts of Zwift races. My warmup is almost the same, been trying a certain number of warm-up protocols (Team Sky, BCC, Wiggins’ one on Zwift, the one suggested here in an article) and I am pretty sure the problem is not in the warm-up.
For all I have understood here and elsewhere, it has a lot to see with lactate buffering and clearance instead.
In that view (if it’s correct @ryan ?) any other suggestion for useful workouts that may help?

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