TR VO2Max sessions, how should they feel and what biometrics are useful indicators?

I started TR because I wanted to stop annihilating myself and actually make consistent predictable progress toward my goals. Not surprising I’m second guessing TR protocol, and wanting to load up and obliterate – have frustration will work it out in sweat.

My HR over all VO2Max sessions I see a steady improvement – from mid 160, to now low 150. Also during this time I’ve seen a +20% improvement in FTP. Happy to be tracking toward goals, however recent VO2Max sessions I’m not feeling challenged.

What should these sessions feel like, and what biometrics can I look at to gauge a session’s effectiveness?


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Vo2max session should feel terrible, gasping for air at the end of the intervals.
HR is not a reliable metric, as HR not rising can be a sign of fatigue. Counterintuitively, HR rising fast can be a sign of great fitness, as your body react fast to the demand.
With a ftp of 140, you may want to focus first on endurance rides, to build your base and increase your mitochondria count. Check out youtube videos with Inigo San Millan.


Thanks for the response.

I absolute don’t feel terrible during these intervals. Breath is controlled and easy, could have a conversation. Most of Pope was between z1-3, barely a blimp into z4. I’m untrained on the bike, but otherwise fairly fit. RHR in the low 40’s, and squat 2x body weight fwiw.

With a ftp of 140

Don’t yet have faith in Ramp Test. First ramp test was 35min, 118. Second 20min, 126 (recovering from covid). Third 21min, 140, leaving me at 2.27w/kg. My goal is simply 3w/kg.

Sounds like increasing to 105-110% on these session would be advised. San Joaquin -5, if the intervals were longer, say 30s, then it would be challenging.

The end of a VO2max workout should feel very, very hard. You might feel the need to gasp for air. I can deal with shorter VO2max intervals much better than longer ones (e. g. 7x3 minutes).

Here is my advice:

  • Make sure you are well-rested and that you are fueling your workout. Don’t think “But I don’t need to, I have enough glycogen in my body, etc.”
  • If you are able to finish a VO2max workout without taking a break or cutting the workout short, it is either too easy or just right.
  • VO2max workouts should not feel easy. If you anticipate them with trepidation, rest assured that this is common amongst most athletes, no matter how strong they are.
  • In case you have failed a workout, make sure Adaptive Training adjusts your training plan and replaces the next VO2max workout with something easier. If you don’t feel well the day of the workout, you can also choose an alternate workout.
  • If you can easily finish a VO2max workout, I would consider choosing a more difficult alternate workout. Do this in moderation and don’t be cocky. (I speak from experience … don’t make the same mistakes I keep doing :wink:)

PS One more thing: judging by your FTP, I reckon you are quite new to the sport. If you are not used to pushing yourself to the limit, VO2max work might feel really, really hard. Basically, you don’t know the difference yet between what your body can and cannot do, and your brain shuts you down prematurely. Learning the difference between a workout being physically hard and psychologically hard is a life-long journey.


Beginner gains here for sure. And I expect to reap those for as long as I can.

Feel adept at pushing myself mentally and physically. Decades of martial arts training. 5 minute plank, 5 min table top horse stance … Last Ramp test did end at 182bpm, I’m not young either. Well versed in obliterating myself leading to stagnation.

Now, fueling appropriately for cycling is another matter. I expect that to be a fun ongoing puzzle. I’ve watched CGM dive into critical low state <50mg/dL.

Okay I think my calibration is correct. TR is not delivering vo2max session to my fitness level. I’ve not seen an adaption in two weeks and ride 3-5 times/wk. Prior I saw those regularly. So maybe that’s the issue.

If you can squat a lot, it could mean that your strength is anaerobic. I would personally go for alternative VO2max workouts that are stretch or breakthrough until the workout is difficult to complete. Pope is only a 2.8 PL, so it’s pretty low. If you mar the workout as easy, the TR algorithm should adapt fast and give you something more to your needs. It can take some time at the beginning to adjust…

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That’s a major issue. Glucose blood levels should not go below 70 mg/dL. I feel like crap at 80 mg/dL. You need to eat more before the workout, and during the workout.

This is getting off-topic, but regarding glucose levels, it’s the first derivative I feel. A large drop in short period of time, is unpleasant and will go loopy. Otherwise I feel fine even at 40mg/dL. And I know that from curious doctors having drawn my blood, asking how I felt, dizzy like I’d pass out – answer “no, I feel normal”.

Pre-cycle meals I’m mindful not to consume foods and/or amounts that spike glucose levels, else may end up on the rollercoaster. So far best solution :wink: is an electrolyte beverage with ~5g sugar per 12oz. That has been most stabilizing for current activity level. Won’t work should I decided to do the Seattle to Portland this next year.

I am not a medical doctor, so please don’t construe this as medical advice. But you should definitely consume more than 5–10 g per bottle. Healthy athletes should aim for 60–120 g/h. Fueling your workouts has a variety of advantages, including lower RPE (rate of perceived exertion, i. e. how hard a workout feels), higher long-term consistency and the latter is the most important factor when it comes to sports.

As far as I understand, your body’s reaction to spikes in glucose are to be judged very differently when you are engaged in physical activity. Especially if your blood sugar is very low, your brain might simply “shut you off” for safety’s sake.

Do you suffer from diabetes? (You knowing your blood sugar levels indicates you are at least keeping an eye on them.) If so, discuss this with your doctor. But you should definitely make sure your blood sugar levels do not pass the relevant critical thresholds — even if you feel fine.

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Will definitely need higher carbohydrate intake to achieve higher sustained power. This will require reparation macros for me. I understand this, and will take time for me to achieve that.

Ketogenic is great for Z2, or brief Anaerobic efforts. Long time ago I used “Advanced Sports Nutrition” 1st Ed, by Dan Benardot, as a guide.

Not according to blood work. HbA1c 4.9% last, fasting glucose 88mg/dL. I started using a CGM precisely to understand what was going on when I felt loopy, and adjust behaviors. If anything, I likely have residual metabolic issues due to history of eating disorder – yes, been through therapy and all that, it’s still a challenge.

Thanks for your concern, and advise. :slight_smile:

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Good to hear you got your eating disorder under control :muscle:

You might want to consider fueling even your Z2 rides. In my experience, caloric control and making fueling a habit becomes way easier this way.


They feel easy until all of a sudden you reach a progress level where they feel like you are dying so ease into them as recommended by AT


Try some longer vo2max intervals (2 a 3 minutes) and see what happens :). If your not gasping for air at the end of the 3 minutes, your doing it wrong, (probably not going hard enough ).

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The VO2 max intervals in the picture above suggest that they are quite short. This won’t leave you in any state of near-panic like a 2 or 3 minute interval will. The effect is cumulative with the shorter ones. So i think they are a bit too easy for you, (maybe your FTP is slightly higher)

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When starting VO2max workouts with TR, initially ignore recommended workouts based on Progression Level (PL), Adaptive Training (AT) system just tries to determine your level. Simply jump into some Stretch or Breakthrough workout and adjust yourself from there. Once you find your starting point, only then let AT to recommend workouts based on achieved PL.

I have similar issue, from previous phases involving VO2max workouts, I know my starting point being around PL ~5, even if AT thinks it have decayed to 1-2. Now I start every VO2max phase with Sleeping Deer and let AT guide me from there.

Beside that, most useful recommendations are in posts above. In addition, keep using high cadence (105+). It helps you reach into VO2max state easier, i.e. shifting stress from legs to cardiovascular system. That’s the goal.


@svens that makes sense to me and thanks for the tip on Sleeping Deer, that looks great!

Not sure when progression gets reset, have only been at TR for few months. Completed a short 2 month program, and started a longer (205 days) program attempting to peak sometime spring. My current threshold sessions are closer to, but less than, what I expect vo2max to be. From what I can tell, it’s duration above FTP that seems to matter most in vo2max. Similarly 200% FTP anaerobic sessions also aren’t taxing due to even shorter duration max effort intervals.

Another thing to consider is that TR calculates VO2Max based on some % of FTP for simplicity sake, but VO2Max isn’t tied to FTP. So divorce yourself from the 110, 120, 130% numbers. increase the % until you get that gasping for air feeling towards the end of each interval.


Yeah, if you find TR proposed starting PL for VO2max easy, anaerobic workouts are likely even more so. It probably means that anaerobic power helps you to fly through VO2max short intervals. I don’t do anaerobic stuff often but during some refresher block, I’ll start with Scollop and progress from there.

Note: both Sleeping Deer and Scollop are good starting points for me personally. For you different PL may be better suited. You just have to experiment.

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Exactly. Max is max, so for vo2 I would go as hard as possible for each interval and then see where that lands you. Vo2 when done properly should feel absolutely horrible.

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This is correct in general. But in TR context, it is good to know some specific hard but achievable workout that can be completed even without recent stuff in that zone. By doing it at the beginning of loading block, it helps AT to quickly determine starting point from where it can start assigning you productive workouts.

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