Can TrainerRoad help raise vo2max given high fractional utilization?

My FTP is getting quite close to my vo2max so I’m bumping against that ceiling.
Which plan (or workouts) are more suited to raise vo2max?

After many yrs of long distance triathlon, I decided to focus on MTB marathons. Given my background, I haven’t trained vo2max much so there’s hopefully low hanging fruits to gain there. Still as a 52yrs old, vo2max is not my forte. Starting last Fall, I completed SSBase MV & SustPwrBuild as per PB recommendation. It went well and raised my FTP from 244 to 265 with PL’s in the 4 to 7 range.I’ve recently struggled with the threshold workouts, whenever there’s time > 100%. Using my 5min pwr best (282W ) as a Vo2max proxy shows my fractional utilization is 94% (265/282). That explains my struggles with over unders and other threshold wo. I don’t believe AT considers fractional utilization.

During winter, I do 2-3 TR workouts/wk as my main sport is DH skiing so no long Z2 rides until Spring. PB scheduled SSBase2 LV which has 1 of each: SS, Threshold & vo2max every week.

Should I swap a threshold for 2nd vo2max ?
Which kind of workout is best for what I need? Should I do 30/30 or focus on 5minutes pwr?

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or more hard starts with suprathreshold power.

all 3 could benefit…,only one way to find out! tee them up. Start with those that you enjoy or dislike the least. They are all tough to different individuals.

Good luck!

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It is possible your FTP is overestimated, something to consider. I’ve got a high fractional utilization, and traditional base 1 and 2 did more to help my time above threshold than the workouts in short or general power build. However I’d suggest looking at the polarized plans as pre-aAT, TB1 and TB2 didn’t have any work above threshold. And FWIW I’ve been able to raise vo2max simply by doing a lot of 90-120 minute endurance workouts plus some endurace+intensity workouts (with few long z2 rides). Experiment and find what works for you.

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It’s possible but unlikely. Over time aiFTP increased steadily back to 265 on Dec1st. Since then I’ve been able to do Threshold PL up to PL 4.3 but bailed out in 3 attempts at PL4.5. All three of these had time >100
If a workout is below threshold, it feels moderate or hard but I can do it; if the wo has more 1or2min >100% , I get out of breath and need a break / have to bail.

Once the snow melts, I’ll go back to doing steady rides (3h +/-) every week. Until then, I’m hoping to find the right kind of plan/workouts to push through this plateau.

I’ll look at those plans you mention.

LOL That’s good advice. Train my weak side. I’ve not done much vo2max and anaerobic. I did a anerobic today and went fine.

My red zone is pretty clear : stuff >2min above threshold. Ideas so far is to

  • increase time in zone with a bunch of 30/30s
  • grit through the >2min above FTP even if it means taking several breaks.
  • tabatas
  • Long Z2 rides once Spring is here

Empirical Cycling Podcast did a really great episode on vo2 max training: Spotify

I use short short type intervals for the first week of two for a vo2 block to get used to putting out high power, but I quickly go to longer intervals as those are where big vo2 max gains are made. I think 30/30, 40/20, 20/10, 30/15, and so on types of intervals have there place as they can be specific to races such as crits, but if you are purely trying to raise your vo2 max because you think it’s a limiter than longer intervals seems like the best option.


I’m looking to do a Vo2max block. I need to raise my vo2max ceiling (5min pwm max = 284) so I can continue to improve FTP (265). I do MTB marathon 25-100miles and no crit. After 2 months of increasing thresholds PL and smashing myself against the wall/ceiling, I need to try something different.

Are 30/30s a good way to improve 3-4-5min above FTP?

30/30s will increase 3-4-5 minute power both through aerobic and anaerobic improvements. It all depends on experience level. If you are relatively new and/or haven’t done a focused vo2 max block, 30/30s will increase above ftp power partly by increasing vo2 max. If you have been at the grind for a few years and beyond then 30/30s will still increase above ftp power, but by increasing the amount of power that you can put out anaerobically instead of increasing vo2 max. In this case, longer hard start intervals at a high cadence would be recommended. I personally don’t like going by a power target since the power decreases throughout each interval as I fatigue, but I keep an eye on it and know it’s working when my breathing feels like I’m a fish on land. Of course, I’m not an expert, and different training works for different people, and 30/30s work for many people to break through ftp ceilings.

I’m new to vo2max intervals.
I’ve been at the grind for many years at Z2 and at SS and thresholds.

Can you hold the current aiFTP for about an hour? That’s one way to figure out if it’s overestimated.


just take a peek to make sure if you do 30/30 you’re getting your HR to 90% hr max or higher, otherwise IMO it’s just too much anaerobic work for the benefit you are seeking (bump in vo2max).

Otherwise you could accidentally improve your anaerobic capacity, where you train your body to produce more energy through the glycolytic pathway which creates more fatiguing metabolites (namely those pesky hydrogen ions that produce the burn in our legs).

This is one reason why I don’t have some athletes do 30/30s because I want them to stay away from z6 as much as possible because we really need them to become more aerobic, and not risk any more anaerobic gains.


I with @Majoeric on this one, and not to get into an FTP debate, but if you can’t hold your FTP for somewhere around an hour then it’s not really your FTP. That said, whilst I find it flipping hard to do a modelled/estimated FTP power level for an hour, it does seem to put all my other zones at about the right level of difficulty.

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Just looking at the threshold workouts, it only looks like you properly get to close to demonstrating true one hour power when the workout level is above 6 and more like 7+ for workouts that are 1hr - 1hr 15 long

If i keep a high rpm, then yeah hr is >90%
If i grind down at 78rpm then it’s 85-90%