30/30 VO2 max efforts

Just completed my first 30/30 session. 3 sets of 7 30s efforts. However my tacx neo takes a few secounds to adjust to the higher watt setting so I found that I wasnt hitting the required watts at the completion of the 30 s effort. Commonly 6-10 watts below. So to compensate I raised the required power setting by 5% for the 2nd and 3rd sets. On looking back I found I was hitting the required power targets originally set at 100%. My question is how do you ride the 30/30 intervals. Flat out and risk power spikes sarly on or constant efforts.

I take the lazy approach and just don’t worry about it. Mark it as Easy and progress quickly onto harder VO2 workouts. They’ll get hard soon enough once you’re on longer intervals and/or higher power targets.


That small a difference is really not going to make any difference. Personally I’d put it on resistance and just go as hard as you can for 30 secs, recover go again.


I second what @GoLongThenGoHome said and use resistance mode… that said, given your question, I assume you are running in ERG, keep in mind that while it takes a couple seconds to ramp up at the start, it also takes a couple seconds to ramp down at the end, so overall, you’ve likely hit the 30s ints at the target power


I have the same trainer and did review the issue with TR. There was no solution other then to get out of Erg. The 30 second intervals will be 27 seconds at the recommended power. It isnt worth worrying about.

Took me a while to find it, but this should answer your question(s):

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Another, slightly tangential tip:

Do 40/20s or 30/15s instead.


Agree with not overthinking it. Just use resistance mode or do it outside.

One small thing though - 30/30s aren’t each done “as hard as you can”. They should be well under a max effort since the OP is doing 7 of them in 6.5mins for each set. When done in resistance mode/outdoors just tune into the hard but repeatable level (exact watts don’t matter). Might take a few goes to hone in on it but you’ll find it before long.


Agree with what others have said, but want to add that one downside to a fantastic training platform like TR is that it shows you those pretty blue lines and makes you feel like you didn’t perform as intended if your lines don’t look perfect. Ignore that. Especially for short sharp VO2 efforts. Just be sure you put in the 30 seconds and don’t worry about if they started or ended a few seconds outside “the lines”.


Yeah, 30/30’s are the gateway to the 30/15s or similar. Looking at your HR during these shorter recoveries is a good way to visualize how your oxygen throughput remains high for an extended period of these short/shorts.

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IMO I don’t think seven sets of 30x30 are enough, especially when you say it takes a few seconds for your trainer to reach the target. Your body probably spends too little time begging for oxygen while dealing with decent lactate levels. You take a five min rest right when you get to the most productive part of the set. I’m okay with not being able to finish the VO2max workouts as prescribed. As @Helvellyn suggested I’d do 40x20s or three sets of 30x30s 10-12 reps.

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Hey @Phil_Bickerstaff,

This is a good question!

The best thing to do here is to simply complete the workout as it is prescribed. Do your best to keep a really steady cadence throughout the sets, and maybe try an even lower gear than usual for these “On-Off” style workouts.

Make sure you’re using the smallest chainring (if you have more than one), and I’d try shifting to somewhere around 3/4 of the way up your cassette or higher to see if it helps. Keeping the flywheel speed low for these types of workouts is going to help to keep your trainer feeling responsive.

It’s totally normal for your average power for these short intervals to be slightly off from the target, so don’t focus on that too much. Rather, focus on your form and knocking out the workout as best as you can. After looking at your latest workout “Coy” I’m confident that you’ll get the proper stimulus from the workout by simply following these steps. :slightly_smiling_face:

From there, make sure that you’re answering the post-workout survey honestly.

There’s a place for every type of workout, and 30/30s are there for a reason! :stuck_out_tongue_closed_eyes:


For 30/30s in erg mode on my Kickr, I have to rev the rpms over 110 3-4 seconds before the interval starts. This prevents getting bogged down when the resistance changes. Then, I resist the urge to fight ERG mode and just maintain the rpms (about 100) until the end of the interval. Average power for the interval will be spot on.


My method for short/shorts is to be around 90-100rpm in the low before the interval, then kick up my cadence right when I feel the resistance ramp up in that 1-2 seconds before the official interval. I aim to hit around 110rpm in 3-5 seconds. This “jump” effectively creates a sort of hard start and overcomes the trainer lag above and beyond TR sending the ERG resistance change about 2 seconds early. Below is a pic of 3 kicks in a 30/30 session on a Kickr in 34x14 ERG with pure cadence adjustments from slow to fast to overcome trainer lag.

A rider can fine tune the jump by the cadence delta they choose. You can minimize the spike by having a smaller rpm delta from the lead-in to the kick. Doing this, I get a solid load in the interval but I don’t even sweat the times I miss the entry because we are taking about general loading on the body and being short on an interval average by a bit is not likely a “problem” in the grand scheme.


I think that depends what intensity you do them at. Plus if you are new to 30 / 30s you may initially find them hard. But as you progress you find you can complete more per set and more sets. They are a good introduction for getting back into your VO2 sets.


Yes and no. For seven 30 / 30s I find that I can recover enough in the 30 second recoveries to go just as hard again. If you do them resistance you usually find what level you can do in the first set / few intervals. Agree that if you’ve progressed the number of intervals and sets then you want to be targeting something slightly lower.

I like to reach that fish breathing out of water sensation before the end of the set. If that’s where I end up and can still complete the set then I’ve pitched my effort about right.


In addition to what @eddiegrinwald said, I wanted to drop this article in here about trainer modes:


Sprint intervals

ERG trainers perform a brief ramp up to an interval’s target power. For longer, less-intense intervals, this ramp-up is hardly noticeable. However, this ramp is more pronounced for short, high-intensity intervals. If an interval is between five and 20 seconds, riders may want to consider riding in Resistance mode to avoid any lag time in reaching their target watts.


Agreed. The blue lines are just there to give you an idea of what the workout is going to be. If you’re power deviates wildly from the prescribed line then maybe dig into it and see if you should do it differently next time. But don’t worry if it’s not riding that line perfectly every second of the workout.

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Yeah, when I do these the first couple need to be paced a bit so you don’t blow up. But the last couple of each set should be more or less all out.

VO2 is around your 10 min max. You should do 30 seconds around that 10 min max pace. If you are going all out that is a great workout but not VO2 and in my opinion a completely different workout.