I’ll pretend to be a smart and say “it depends”! Shorter rests mean that you’ll be less recovered for the next interval. So HR at the start of the next interval will be higher, and you’ll have less chance to “re-charge” your anaerobic battery, meaning more aerobic contribution/stimulus.
On the other hand, a certain amount of power (or maybe “work” is a better word) will be needed to get you to VO2 max. No point having short breaks if you can’t then do the work. So you’ll need to find the right balance to maximise the stimulus for you.
IMO I wouldn’t go longer than 1:1 work/rest. When I’m going this hard (which is ****ing horrible) I want to squeeze the most from it I can, as I don’t do it more then a couple of blocks per year.
Will let someone smarter chip in additional thoughts!
If you are gasping for air - it’s successful. When you cannot generate enough power to elicit this state of breathing - go home. From interval to interval your power will be lower if you are going max but the breathing should be there even with lower power.
Its 8 times 4 minutes. Starting a 120% and fading back tot 108% in 2 minutes and then keep it there for another 2 minutes with 2.5 minutes rest in between.
The previous one was 4 minutes at 110% and I definitely feel a difference. My HR and breathing rises way faster with this hard start without exploding during the 4 minutes :).
Again there is no standard prescription for VO2 max (other than maybe “all out”), so take all of this with a grain of salt…
I know %FTP isn’t really the most useful measure of how hard a VO2 max interval is from person to person, but your intervals look more like what my 3rd or 4th 4 min interval might look like when I’m wondering if I’ll make it through - and I’m 100% diesel. In other words, are your earlier intervals hard enough? Are you gasping and legs on fire?
FWIW analysing post-workout, I only dropped below 120% after about 2 mins of first interval on the two occasions I’ve done a 6x4 this year. Remember if you are following KM’s guidance these are supposed to be all out, so would expect to see higher power tapering off during each and across all intervals.
Then again you did so much work (and short RBIs) that by the end, there’s a chance you did elicit good VO2 max stimulus - but guess it’s impossible to say what’s optimal.
Perhaps I’m spouting rubbish - thoughts from the man himself? @empiricalcycling
Edit: I don’t doubt that your workout was better than flat intervals at 110%, so I think you’re on the right path to optimisation.
The literal interpretation of this would be a Wingate test every interval. I don’t think that’s something that many people would do - and probably not make for a very good vi2max workout.
The goal with the hard start is to quickly elevate HR. And the remainder of the interval needs to be hard enough to keep your HR at appropriately elevated level. But the hard start is not an all-out Sprint. If it was, people with high anaerobic capacity would destroy themselves in the first 10-20 seconds, and not be able to turn the pedals by 30 seconds. Ie Wingate test.
I keep wondering about that. I really struggle with vo2max workouts (lol…), in that I find it nearly impossible to do more than 90 seconds. I think I might have (relatively to me) high anaerobic capacity, and poor vo2max. However in normal riding, I can “mask” the poor vo2max by tapping into my FRC, but I can’t actually ride at vo2max for very long.
Yeah the main goal of the workout is to get as much time at VO2MAX as i can take. And if I start to hard, my legs are fried before i’m getting to VO2MAX . Maybe this is still on the safe side, but i managed to get at least 14 minutes of really high quality time @ vo2max (first set i was still way to fresh at the end of the 4 minutes).
Yes, it’s probably been covered here before, but good reminder - “all out” is meant to apply to the interval portion of the workout as a whole. So yep not a full on sprint out of the gates, but not conservatively paced. This helps to explain why power should taper off over the course of the workout, but not drop down really far to Tempo or something like that.
Was vo2 max breathing there? Like @4ibanez said it is highly individual.
For comparison, this is my 5x4. I am…I do not know what I am, as my anaerobic capacity is poor but 5 min power ok’ish. Nevertheless, it’s done purely by feel with doing intervals as hard as I (of course with thought the back of my mind how many intervals I have to do). The blue target from TR is 115% of FTP (for reference)
From 20min of work, 16 min was over 95% of VO2 max according to WKO5 (just reference point). Breathing of course was severe, every interval was done with RPE 9-9,5/10 (10/10 is for me 5min test when I fall off the bike and cry). It was the third vo2 max workout from a total of 4 in that week. So listening to KM and his whole idea of VO2 max, and also from Tim Cusick - max is max, just sit on the bike and rip as hard as you can. Doing this there is no possibility I could do 8x4 with 2,5min of rest. 5 is enough, I could maybe squeeze 6th with some great willpower. But you could see some difference in heart rate kinetics in the 3rd interval where hr rose more gradually - ending very high but it took way longer to rise up (I was gassed after two intervals before).
Of course, @SpareCycles has great articles about that, showing how your body is responding. Basically, hard start should be hard, >pVO2max to elicit a rapid heart rate response. In the end - if breathing is there it should be good enough to qualify this as a good vo2 max workout, despite hard, not hard start etc.
This moment during the interval (1min and 50 seconds in the interval), my heart rate maxed out at 175 and stayed there almost the entire time (94%max hr). And RPE was a 9 - 9.5.
Going to record it next week with my Garmin to see if my breathing is maxing out as well. But i think it does
If I could add my 2 cents, from what I remember, Kolie said he’d prescribe about 15-20 minutes of work, so probably 5x4-minute intervals; if you go all out, this is enough time to elicit the adaptations you’re looking for and doing anything more than that is just doing unnecessary extra work.
Correct me if I’m wrong. Otherwise, I agree with what Jarsson and Ibanez said. I just finished week 2 of my VO2 block and it sounds and it is absolutely brutal.
. Maybe this is still on the safe side, but i managed to get at least 14 minutes of really high quality time @ vo2max (first set i was still way to fresh at the end of the 4 minutes).
