Heart rate during 30/30s versus longer intervals

Just in my first week of my second trainer road plan after a couple weeks of less structured but quite intense riding and then an easy week to recover up for the new plan. I believe my ftp is set pretty appropriately at around 284 which might be even a bit low going by some of the numbers I was doing on longer climbs during my less structured weeks.

I did a 30/30 workout today, which is probably my first hard 30/30 workout and in terms of difficulty it was definitely hard (gendarme +8 so 140% ftp). I noticed that compared to similarly hard v02 sessions at lower power but longer duration my heart rate never climbed quite as high even at the end of each block of work.

Is this typical for 30/30s given the short duration and repeated breaks or should I realistically need to go even harder on each one…or is it a sign I am maybe not recovered enough? Otherwise feel fine and was able to finish the workout though it was mentally difficult to do so many reps for me versus the mentality of “just a few more” when the sets are longer.

Curious to hear anyones thoughts and experiences.

Heart rate is something that varies quite a bit from athlete to athlete, so it’s totally possible that this is “normal” for you.

If your FTP feels like it’s set correctly and you still felt fine during the workout, I don’t think you should be overly concerned with a higher HR for efforts like these ones.

While you do have repeated breaks between short bursts in these kinds of workouts, they are still intense sessions, so it would make sense that your HR might shoot up a bit – especially as you get deeper into the workout and all those efforts start to compound. Your HR won’t go down quite as low during your “off” intervals as you do more and more efforts, which means you’ll be hitting the “on” intervals at a higher initial HR, so it’s normal to see your HR creep up.

Good call on checking in on your RPE, though! That’s an important part of your training to consider. If you start to feel flat/fatigued or unable to complete efforts as you get deeper into these kinds of sessions, that might indeed be a sign that you may not be recovered enough. For now, though, what you’re describing sounds expected to me.

Hope this helps – feel free to let us know if you have any other questions on this!

The phrase often used in the studies on micro intervals is 'maximum sustainable pace’ i.e.somewhere between max aerobic power and flat out. It follows that ERG mode and a fixed percentage of FTP may well not hit the spot.

Another problem with generic prescription of micros is body composition: the shorter the work interval the greater the relative contribution from anaerobic capacity so if you’re a sprinter you’ll need to work far harder to maintain 90% HR than I do (all day guy with the sprint capacity of a stoned sloth): for me 130% FTP is enough to do the trick whereas 8 min intervals go at almost 115%.

Lastly have a look at the rest interval length: you might find that 15secs rest is short enough that the work intervals get you to 90% and keep you there.

TL;DR resistance mode and as hard as you need to keep above 90%HR for as long as you can cope with.

30/30s aren’t vo2 but anaerobic work. The rest is too long for your heart rate to get anywhere near maximum uptake if you aren’t unfit.

Do 2:1’s if you want to do on/off vo2 (30/15, 40/20 etc).

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I’ve also found that my HR doesn’t get quite as high during on-offs which I think is simply due to the frequent rest intervals. :anatomical_heart:

More “traditional,” long, sustained VO2 Max intervals might push you to true VO2 Max more effectively, but this doesn’t mean that 30/30s aren’t a good workout – they just have different goals than workouts with longer ~4-5 minute intervals.

It sounds like Gendarme +8 was a good workout for you, so I’d say that it was a success regardless! :muscle:

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Hey dude. I think I’ve answered this question or a similar question about 5-6 times already on the forum - the “I did on-offs and I don’t know if I hit VO2”. There are tons and tons of threads where this labelling confuses users.

Do you think it might be appropriate for TR to reclassify 1:1 short on-offs (aka 30:30s) as Anaerobic in the app, rather than as VO2?

I appreciate they are “easier” for most people, so could be considered an introduction to higher intensity - but you could also replace these with 1:0.5s (e.g. 30/15s, 1min/30s etc) at a lower % of FTP?

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Thanks for the feedback!

I agree that there has definitely been some confusion regarding VO2 Max workouts and whether or not each of them is designed to bring you to your true VO2 Max or not and further, how each individual athlete can tell when if/when they are, in fact, working at VO2 Max.

We typically categorize most of our workouts based on the power zone that they are targeting rather than any one physiological state that you might encounter while doing them. This can be confusing because you might not reach your true VO2 Max when doing all of our VO2 Max workouts, and the same sort of applies to the Threshold power zone with the varying structure of the workouts in that classification.

LT1, LT2, and VO2 Max are all somewhat specific physiological states that we work around in a variety of different workout styles. There are Threshold workouts where you are definitely working above LT2 at certain points (hard starts, over-unders, etc.), but the focus is still on lactate tolerance/clearance near LT2. The same goes for VO2 Max workouts. The goal of some of those workouts (on-offs for example) isn’t necessarily to spend time at VO2 Max but to get more comfortable spending a good amount of time in that specific power zone.

This is one of those things where it’s hard to please everyone, but we are listening to your feedback and I’ll make sure to bring this up to the rest of the team for discussion. I do agree that there is a lot of terminology in cycling that could be improved given what we know now! :sweat_smile:

Thanks again for the feedback and for all your help!