VO2: 5x5 continuous or 5 individual efforts?

Whilst I have a perfect hill that I use if I want a 5x5 Vo2 max session (with perfect 5 minute rest intervals!), what (if any) are the real world benefits of doing them continuously as opposed to a general ride where I can ride different hills but the rest might be as much as 9 or 10 minutes?

Is the main factor here that heart rate will not be elevated? What if I could nail each interval with a longer rest at 118% but maybe only hit 110% for the last 1 or 2 if doing continuous.

A brief science lesson welcomed.

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The purpose of doing them with not too much rest is to create the proper stress level in your body. Chad at TR did this talk in the podcast 261 i think. Like doing short shorts as chad calls them 30 sec with 30 rest. The Creatine/Phosphate cycle takes between 1 to 3 minutes to recover. If you make the recovery too long then heart rate drops a lot hence when you come to do the effort getting the Heart lung working again feels really tough and later intervals are difficult. Hence you are finding the last 1 or 2 are needing to be done at 110%, This is still a VO2 effort. It Might be better to try 115% with the same recovery time and see if you can nail them all at 115%.

Your VO2 system will not be taxed doing single reps as it would by doing a set of reps.

Think of doing 20 push-ups in a row vs doing 4 push-ups 5 times spread over 12 hours.

Remember, VO2 is NOT a power target. You are not doing VO2max workouts to develop 5min power; you are doing them to develop a physiological process – uptake, delivery, and utilization of oxygen. Power is set as a general guideline because generally this point works for most people to illicit VO2 adaptations.

However, many studies have shown VO2max intervals can still force growth at lower power levels (e.g. 100% FTP). Even if your last couple of intervals are at reduced power, what are your other markers like HR and breathing telling you? Your legs might not be able to produce that power, but that does not negate the functions of the rest of the VO2 chain.

Have fun on that hill. :+1:


Great answers both :+1:

Continuous it is!

If you were looking to increase absolute 5-min power you could and should definitely increase the length of the rest/recovery interval so that each 5-min power interval is done absolutely the most fresh. Like other’s have said, for repeatability you want as little rest between intervals as you can handle.

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Wouldn’t how often you do such workouts and how motivated you are when you do them have a bigger impact than precisely how you do them?

I’m going to do them twice a week for the next 4 weeks. Motivation won’t be an issue. :+1::+1:

Maybe switch it up then.

TR’s Elephants is 6x5min @ 108% with 3 minute recovery valleys.

5 min is a good amount of recovery. You should be able to push higher watts. Maybe 110%.

You can also try hard starts to minimize the delay before reaching VO2max. Because a real life hill is fixed length, your overall interval would also be shorter.

That would certainly be a really killer workout if you can nail that 5X, with any length of recovery interval. Seems pretty daunting, as it’s pretty much all out.

Which begs the question though… if you dial back your power to 110%, how long is the repeat? Would it be closer to 5:30-6:00?

Not another doping thread…


It’s not all out, though. All out would probably be 5-10s power, 30sec power at the most.

You don’t even want to do short/shorts using all out power because it won’t be repeatable.

I recently did Mount Foraker, 7x5min @ 112%, with over 24min in VO2max. However, I was doing hot starts @ ~175% which is around my 1min power. Most of the 5min was spent around 100%, definitely not all out, yet resulting in much more TiZ than doing the intervals at the prescribed 111%.

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I meant all out in terms of absolutely nothing left in the tank, not unlike a ramp test.

After 3ish minutes @ 118%, you’d be digging real deep for a further 2 minutes.

How else am I going to get faster w/o doing VO2 intervals? :rofl: No, just weird screen protector/predictive typing doping — I hate both.

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@Supermurph19, here is my opinion for what it is worth. Let me explicitly state some assumptions:

1.) VO2 max adaptation is maximized by spending time at or around VO2max
2.) More time at or around VO2max means more adaptation

You will spend more time at or around VO2max if you do the ‘5x5 continuous’ workout. The accumulated fatigue of previous efforts will allow you to get to a VO2max condition faster in the next interval.

For me, the first interval is the critical one. :smiley: I’ll post a pic below but I found that I had to go WAY HARDER in the first interval to make O2 consumption match the 2nd (or 3rd or 4th) intervals. If you wait 10 or 15 minutes between intervals you have to do that level of effort every time and that sucks.

But even with a constant effort 5x5 approach you won’t start to maximize work at or around VO2max until probably the 3rd interval.


Nice post thank you

from a science standpoint i think it was answered really well; the key of real world is that a race is going to be more like the go HAM for 5 minutes, get to the next climb, GO HAM, etc etc. So by #5 in the second scenario, you will be more kj’s deep…a different type of workout, for sure, but so much benefit.

you know i’m a big fan of different stimulus so my vote is do both kinds!

good luck out there!!!



Is it the time “around” VO2max, or how close you actually get to 100% of it that really matters?

I ask because I see lots of workouts designed to maximize time around VO2max, but I don’t know of any data to actually show that that matters.

Related: does it matter if you get to VO2max by drifting up to it, or are adaptations maximized by hitting VO2max at a higher HR and lower SV?

You want to be maxed out for as long as possible. The answer for VO2 intervals is… go harder.

Aren’t those two somewhat contradictory? I mean, if I go as hard as possible, I won’t be able to go as long as possible. So which is more important?

Guess you need to train more. :muscle:

Nah, the days of chasing the $12k dream are now behind me. I did get to see parts of the world I wouldn’t have otherwise, though.