Hi @robertehall1, the episode where we discussed these intervals was 113 with Sebastian Webber. We actually discussed the name “VO2max intervals” in that episode and brought up the fact that the title gets thrown around but it’s more important to understand what the intervals are about. Sebastian wasn’t a huge fan. My feeling is that there is no one proper title, but they are frequently called VO2max intervals.
I’m not a fan of them because they are extraordinarily hard to execute. A single 5 minute effort at VO2max done hard properly should leave you pretty wrecked. To do five in a row at that intensity is almost impossible. As a result, most people don’t do these intervals hard enough.
In my opinion there are better ways to target the same energy system(s) that is more doable - two good ones are 1 minute intervals with 1 minute rests and 30 second intervals with 30 second rests.
In terms of gains in VO2max, most of us hit our peak VO2max very early in our cycling careers and its debated whether we can actually improve our VO2max at all once we’re fairly well trained. My feeling is we can budge it, but not much. So, I personally feel that while 5 minute intervals with 5 minute rests are frequently called “VO2max intervals” they don’t directly target VO2max. I think they target a variety of systems including our ability to recruit anaerobic metabolism.
In terms of why different intervals take different timeframes to see gains, it’s because they target different energy systems and some energy systems take longer to adapt than others. As a general rule of thumb more anaerobically targeted work takes less time while aerobic work takes longer.
Good stuff, thanks! Do you like the Ronnestad short stacked intervals for VO2 development (3 sets of 13 X 30sec:15sec)? I’ve been consistent with 4X8 min threshold intervals all winter. I’d be interested in more discussion on how/when/frequency to add in the VO2 intervals. Maybe an idea for a podcast or Q&A.
Hey Robert, I’m not as familiar with Dr Ronnestad’s specific intervals but they sound like a variation on Tabata’s which I am a big fan of as we move into the season. There’s a lot of different versions - 20/10s, 30/30s, 40/20s, etc. Each works slightly different systems but they all focus on our “top end” systems such as anaerobic capacity.
That type of work takes much less time to maximize the gains. I’ve seen studies that show you get most of what you’re going to get out of them after six to eight sessions.
@robertehall1I’ll echo Trevor’s response on the # of sessions. 6 is my minimum that I’ll target in a block, upwards of 8. I do like that approach of the 30/15 as the 2:1 work to rest ratio aligns nicely with achieving a high % of VO2 max as shown in Dr. Seiler’s Workshops on the short stack intervals.
@ryan and @trevor and @ThermalDoc - so I’m reading this thread a little lagged… but I’m curious about Ryan’s comment that the hard start would throw heart rate response ‘out the window.’ I realize the original focus of the thread was on 4x4 at 108-110% of FTP kind of range, and that threshold intervals are obviously different – but the thread kind of morphed over to talking about threshold. So, here’s cheap Zwift images of 2 workouts… left one is ‘hard start’ or ‘primed’ with 30s 120% into 5 minutes at FTP, 3m rest in between at 55%. Right one is 5x5minutes, 90s rest, nominally 100%FTP, although i raised it some for reps 4 and 5. HR is more squared off in the left one. Same HR max. Pretty much the same TSS, avg watts, etc. I can tell you the primed version is harder, which is part of the point Ryan was making! The 30-60s settling back into threshold after the 120% is tough. For the 4th one I had to talk myself into it - not to worry, some sense of recovery would come despite being at FTP.
I could grab my Xert charts if they would be easier to discuss, or see what intervals.icu would do with the data (just read about that on Ryan’s post; haven’t tried it yet). I don’t have wko5.
@TKskate, thank you for clarifying. Yes, my comment was specific to approaching the 5x5 with a hard start and keeping the short recovery. I actually did that on a workout not long ago where I was starting hard (not 120%, but still hard enough/above threshold) and saw a continued rise in the HR response. So that ride was much more challenging to complete and I would suggest that if the goal was to target that aerobic metabolism, I missed the mark for some of that session.
Yes, the rest was different in the two rides. For the primed FTP version, it was 3 minutes rest, and for this version of the straight 5x5’s it was 90s. Eyeballing my charts, I feel like I had sufficient recovery in both versions, and that i could have gotten by with even a touch less. certainly the straight 5x5 can do w 60s. The primed one maybe could drop the recovery to 90-120s. I think one can make a case for both versions – not in the sequence i did them!
What would you recommend for FTP % goal for 4 min VO2 intervals? 110-120% FTP range?
How would you recommend progression of these workouts? I’m focusing on VO2 work for the next month.
(1) progressing the number of intervals, with the same FTP % target; or,
(2) keeping the same number of intervals, but increasing the FTP % with each subsequent workout
Hi @robertehall1, great question. When I’m doing these, start my first session as 4x4 at somewhere in that range, but don’t set a hard target. I’ll usually aim for closer to 120%, and use my HR response and perceived effort to adjust and maintain a consistent effort throughout - if that’s 110%, completely fine. Other days if things are going well, it might be 130% or higher. I really let the HR and sensations in the legs guide me.
After that session, I’ll go for between 4-5 intervals, 2x per week for that block. So in reply to your options in question, it’s a little of both. With the goal being to accumulate time in zone 5, I’ll look at my weekly total goal time and keep it fairly consistent because it’s hard sometimes to keep accumulating more time as you build in fatigue with this kind of work.
I would recommend consistency, so rather than try and build %FTP week over week or extend the number of intervals to the point where you’re doing like 40 minutes of VO2 work in a single session, I’d rather see someone consistently accumulate, say, 35-40 minutes per week over 2 sessions and not over-cook themselves since those sessions are so taxing.
If you’re progressing, it could look something like this at the same FTP target:
Week 1: 4x4 day 1 + 4x4 day 2
Week 2: 5x4 day 1 + 4x4 day 2
Week 3: 6x4 day 1 + 5x4 day 2
This would be what I would consider a fairly advanced progression. Even with some pros I’ve coached in the past, we would stick with 5-6x4-5 min intervals for zone 5 work 2 days per week. We’ve done the occasional overload block of 8 sessions over 4 days (AM+PM) as 5x4 minute intervals and then take big recovery to give you an example of an extreme option. But overall we never really exceeded that per session 5x4 time frame.
It could also look like like this as a 2-day block:
Week 1: 5x4 day 1 (115% FTP) + 4x4 day 2 (120% FTP)
Week 2: 4x4 day 1 (115% FTP) + 4x4 day 2 (120%FTP)
Week 3: 6x4 day 1 (115% FTP) + 4x4 day 2 (120%FTP)
What are your thoughts on how you’ll arrange this block so far?
Ok, sweet, I think I’m in the right ballpark. I was going to do one Ronnestad workout per week and one 5X4 min per week. I think I’ll try to progress the interval numbers for the ronnestad, and the FTP % targets for the 5X4min. Thanks for the advice.
My first one (earlier this week) was 3 sets: 10 X 30s:15s at 130%, 10 X 30s:15s at 125%, 10 X 30s:15s at 120%. I think I"m better at the on/off compared to steady 4 min as my anaerobic capacity/repeatability is relatively good. The steady 4 min interval is harder for me.
I’m asking, as I’ve noticed some people refer to them as any of the list above.
Having read through this thread, it’s interesting to see the comments about ERG mode and self-pacing. I have a non-smart wheel on trainer, paired with a left-side PM. That means all my training is done this way, or out on the road. Does ERG mode make a big difference, or is it just convenient? I ask, as many of my friends that I guide/coach use ERG mode, and they struggle with certain workouts; especially when going from 40% of FTP to the range at 106-120%.
BTW, here’s my workout from earlier today. I’d consider it a success, but not sure what the experts would say.
@geraldm24, I usually refer to them by their ‘intervals x duration’, or 4x4, 5x5, etc. and try not to attach too much extra information to them right away.
The ERG mode point is a great question. I think there is a convenience factor, for sure, and like it when your goal is to remain as steady as possible with intervals or just mentally you want to not think about things too much. Just get on and pedal. My preference is to limit ERG mode as much as possible because I prefer to help riders develop that “feel” - I have a long-time client that loves, loves, loves ERG mode (and I can’t talk him out of it! ). Just the other day he completed a long ride that had some relatively wide power targets in it and was frustrated when riding outdoors because of how much the power jumped around. Aside from that being the nature of power, some of that frustration can come about when you move from all ERG mode training indoors to attempting to replicate workouts outdoors. Learning how to use your gears, and make micro-adjustments in your cadence, etc. to keep steady is a really important skill that we all can continue to work on. So my bias is to push riders, whenever possible, to creating power on their own rather than letting the computer/trainer set it for them.
In addition, when going >FTP on those sessions, I sometimes find that on days when the legs are good, but not great, that load that the trainer puts on the legs when you have a specific % set is just too much, and then you’re left reducing the % to find what power feels reasonable to the legs (by that time though, you might just be wrestling the bear, no longer producing quality work). In those >FTP sessions, I prefer to give riders a range to aim for and then have them settle in based on their internal response (RPE, HR) on any given day. They can still get the workout accomplished, and it doesn’t have to be, e.g., exactly at 107% or 112% - they can get the quality out of a range.
Since we are talking 30 / 15s. I gave them a good run for their money in June / July 2020. Events were cancelled and the gains have gone now but I did enjoy them. I adjusted the percentages of the in intensity in erg mode till my heart rate was peaking between 90-93%. I progressed them from 3 x 8 x 30/15 to 3 x 13 x 30 / 15 then would rotate back to 3 x 8 x 30 / 15 at a higher intensity.
I did set some personal bests on local 4-5 min hills that July. I’ve only managed to get within 10 seconds this summer past. It was great for those length hills you can do above threshold and near VO2max.
Here is my heart rate response from a 3 x 12 x 30/15 in July 2020. The short 15 second recoveries were great for keeping the heart rate high during a set. With 30/30s my heart rate drops much further and I’d end up nearer threshold HR.
My workout was 15 min warm up, 3 sets of 12 x 30 / 15 with 3 min recoveries between sets, then a 15 min cool down. This workout below was an hour and 2 mins.
Great workout analysis. Those are so much fun, and yes, I find that when it’s 30/30 you tend to settle in closer to a threshold HR response, whereas the 30/15 keeps it somewhat above. It seems like you timed these well, and although the events were cancelled, the body responded well with those PRs. Nice job!
I eventually invested in a Kickr Core, thanks to my Bank/Health Insurances’ wellness program (zero cost in hard currency; all loyalty miles. The plan wasn’t to buy it exclusively for my benefit, but also so I understand the system when working with my “athletes”. Some mates are IT challenged and can’t get the workouts working in free mode. Now I can assist, properly.
I must say as my first proper workout on it today, having erg mode was good for the motivation; that 4th 8-Min interval was a bit harder than I had hoped for, but having it on ERG mode help me to hold it until the end. I can see/feel the benefit of having it, but still prefer the self pacing efforts as it requires attention to the feel.
). Just the other day he completed a long ride that had some relatively wide power targets in it and was frustrated when riding outdoors because of how much the power jumped around. Aside from that being the nature of power, some of that frustration can come about when you move from all ERG mode training indoors to attempting to replicate workouts outdoors. Learning how to use your gears, and make micro-adjustments in your cadence, etc. to keep steady is a really important skill that we all can continue to work on. So my bias is to push riders, whenever possible, to creating power on their own rather than letting the computer/trainer set it for them.
