VO2max on bike when tired: Triathlon Forum: Slowtwitch Forums

VO2max on bike when tired

Nov 4, 20 12:25

Maybe one of the coaches here with a bit more experience can help me and my friend with a question...

Today I did a VO2max session on the bike - the 3rd session from Zwift Academy:
4x6 minutes with 4 minutes rest
Each 6 minutes was:
50 on/10 off/40 on/20 off/30 on/30 off x 2
On = 120% and off = 55%

My body was a bit tired from the last few days of harder training - but the session was okay and I did the last two 6 minutes around 130% of FTP.

My max heart rate on the session was 160 and I only had 35 seconds above 157 which is 90% of my maximum heart rate. 90% of maxHR is what I read the ‘place to go’ when training my VO2max and 120-130% of FTP should also be a good place to train my VO2max.

My question is something like:
My output/power was in the VO2max area with 16 minutes above 120% of FTP, but my heartrate/internal load only had 35 seconds above 90% of maxHR. Was this session still a true VO2max session or how should I classify this workout?

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Long Distance PB: 8:25
Instagram: larsschmidttri

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Re: VO2max on bike when tired [Schmidt-DK] [ In reply to ]

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imswimmer328

Nov 4, 20 12:52

Post #2 of 11 (1570 views)

I tend to think of on/off sets like that as anaerobic capacity workouts rather than vo2 max. You do reach vo2 max, which is more felt in your breathing than anything else, but you spend so little time there that it isnt as effective as just doing 4x6 min because of all the recovery. The emperical cycling podcast did a really interesting series on vo2 max that changed my perspective on this kind of training.

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Re: VO2max on bike when tired [Schmidt-DK] [ In reply to ]

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mcalista

Nov 4, 20 15:28

Post #3 of 11 (1490 views)

These short interval-short recovery workouts ARE VO2Max workouts, as you maintain a high level of oxygen uptake throughout the set, rather than the drop in oxygen uptake you typically get in the longer recovery interval of the classic 3 minute VO2Max workout.

There is some evidence that the longer interval method is slightly more effective at raising VO2Max, but the short-shorts take less of a physical and mental toll on you - and there is a LOT to be said for that when looking at your overall training week. They are also an excellent stepping stone at the beginning of a VO2Max block of 3-4 weeks towards longer intervals. I'm not familiar with the Zwift Academy approach, but 3rd workout in sounds like a good place for these.

Short-shorts are also good at maintaining VO2Max without adding huge amounts of training stress.

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Re: VO2max on bike when tired [Schmidt-DK] [ In reply to ]

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desert dude

Nov 4, 20 16:13

Post #4 of 11 (1469 views)

Schmidt-DK wrote:

Maybe one of the coaches here with a bit more experience can help me and my friend with a question...

My max heart rate on the session was 160 and I only had 35 seconds above 157 which is 90% of my maximum heart rate. 90% of maxHR is what I read the ‘place to go’ when training my VO2max and 120-130% of FTP should also be a good place to train my VO2max.

My question is something like:
My output/power was in the VO2max area with 16 minutes above 120% of FTP, but my heartrate/internal load only had 35 seconds above 90% of maxHR. Was this session still a true VO2max session or how should I classify this workout?

What does vo2max stand for? What is the purpose of a vo2max workout? If you ask those questions I'd grade this workout as not meeting the end goals.

Brian Stover USAT LII
Accelerate3 Coaching
Insta

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Re: VO2max on bike when tired [Schmidt-DK] [ In reply to ]

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rockdude

Nov 5, 20 6:56

Post #5 of 11 (1306 views)

Schmidt-DK wrote:

If I understand your question, it is about power Vo2 vs heart rate Vo2 and where did this workout land. We can quickly get into the weeds on the physiological response of this this workout so I want go into it. In General, if I were you, I would look at the power to classify this workout. Your heart rate response was likely depress from several days of hard training. Try this workout fresh and likely you will see a higher heart rate. If you think the workout was not pushing you hard enough try bumping up the power to 130%. If you really are trying to replicate a true Vo2max response, then do the on sections of the intervals all out and go to failure.

BoulderCyclingCoach.com

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Re: VO2max on bike when tired [rockdude] [ In reply to ]

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jn46

Nov 5, 20 7:54

Post #6 of 11 (1260 views)

I raised the same questions with coaches and people significantly more knowledgeable than me back in the summer. Essentially I was struggling to get the HR up into vo2 zone, albeit power was there, so was wondering if I would be getting desired adaptations.

Advice similar in that fatigue, even small, can play a big role in HR response, and its likely the sets you are doing aren't long enough to see the HR lag.

I was doing a lot of microburst 40/20 (3 sets of 12 mins), alternating with what I thought was classic 3 min intervals.

On advice I ditched the 40/20 and moved to 5 minute intervals, aiming for 6 in total but doing as many as I could, usually falling short of 6. Those extra two minutes made a significant difference in HR response. When/if I go back to microburst I'll probably try 50/10. I think if you are well trained already 30/30 is too much rest, and 6 min sets too short for microburst.

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Re: VO2max on bike when tired [Schmidt-DK] [ In reply to ]

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Geronimo

Nov 5, 20 9:28

Post #7 of 11 (1226 views)

I'm guessing the next v02 max workout will be extending the intervals? I.e., instead of 30/30s it's 60/60s, building towards 3-5 minute reps or something? I've seen v02 max progressions that start with workouts like this, which I think you could call a "v02 max prep" workout more than a v02 max workout. You're working at a power level that if you kept going, you'd probably reach v02 max, but you're not actually spending any time consuming as much oxygen as you're capable of.

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Re: VO2max on bike when tired [Geronimo] [ In reply to ]

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jn46

Nov 5, 20 9:41

Post #8 of 11 (1210 views)

60/60 would be too much rest for vo2. Natural progression for microburst would be 40/20, 50/10 then just extend the number of reps and sets.

I've also read a good way to target vo2 for the longer intervals is to do a big effort, well above vo2 and into anaerobic, for the first 30 secs to a minute to get everything raised to make the most of the interval.

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Re: VO2max on bike when tired [Geronimo] [ In reply to ]

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desert dude

Nov 5, 20 10:32

Post #9 of 11 (1191 views)

Geronimo wrote:

You're working at a power level that if you kept going, you'd probably reach v02 max, but you're not actually spending any time consuming as much oxygen as you're capable of

Which is a big clue as to how vo2max intervals should be done. Remember all, vo2max is when you increase the workload but there is not an uptick in o2 utilization.
Now think about the body's response to that sort of demand.

Brian Stover USAT LII
Accelerate3 Coaching
Insta

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Re: VO2max on bike when tired [desert dude] [ In reply to ]

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bentus

Nov 5, 20 11:03

Post #10 of 11 (1170 views)

With all work above threshold you will reach vo2max if continued for long enough. There is an intensity duration trade off which 40/20 and intervals like that try to maximize but science is not 100% clear where the exact sweetspot is with intensity high and duration long enough to create the best stimulus.

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Re: VO2max on bike when tired [bentus] [ In reply to ]

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desert dude

Nov 5, 20 11:15

Post #11 of 11 (1154 views)

bentus wrote:

With all work above threshold you will reach vo2max if continued for long enough.

it should read: With all work you will reach vo2max if continued for long enough - fixed that for you

Brian Stover USAT LII
Accelerate3 Coaching
Insta

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