Indoor vs outdoor sweet spot 2x20

Yep. End of the year last year my intervals looked like yours. Practice, practice, practice makes things better for sure.

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I live in an area with pretty much continuous short rolling hills like what you’re describing and did a fair amount of outdoor workouts last year (and the last 2 weeks as we’re getting spring weather in the Carolinas. Couple thoughts that I have:

  1. There’s absolutely value in doing steady/sustained workouts outside even if your power fluctuates, especially if your target type of riding involves sustained power. It’s an important skill to be able to control your power on variable terrain or in changes of pace, especially if your doing any longer events or rides. To you exact point, 2 20’ intervals may have the same NP, but one where you’re constantly spiking into VO2 range is going to be much more costly than keeping the power in say a 20% range.

  2. One of the best ways to control you power spikes is to anticipate the terrain, and adjust your power/shift proactively. This means downshifting right before you hit an incline and shifting down early enough that you never feel excess strain on your legs going up a roller- conversely, shift up a gear and focus on pushing down right as you are cresting a hill to avoid having your power drop on the downside. My NP is always a little lower on rolling terrain than flat because I avoid having spikes which take me way above my target zone. But you make up for that because outdoor workouts are usually longer including time to ride to and frim your spot for intervals.

  3. There’s some intervals that you’re just better off doing on the trainer. For example, over/unders can be tough to do on rolling terrain, especially if you have steep uphills and downhills. Any workout where you’re trying to stay in a very tight power range is also probably better on the trainer (think intervals just over threshold like Stromlo or Black Hawk)… Depending on your event (like a TT), you may want to do them outside as it gets closer to practice dialing in your power, but early in the season, you’ll spend more time at your goal intensity indoors.

As an example, here’s a workout I did outside on consistent rolling terrain on my TT bike- targeted one hour at 90-94% FTP. You see some variation (the drops were from the couple busy roads I had to cross), but I’m largely right within that range.


Here’s McAdie +1 outside last week. Again some variation, but got pretty close on all the intervals with proactive shifting. I did choose a flatter route for the first 2 intervals which is why they look better.


Hope this helps!


I’m not good at holding long intervals outdoors stable powerwise but my mate is. On a sporting TT though I seem to hold more steady power than him though. He’s about 4mph or more faster and usually wins or podiums. It won’t obviously be as simple as the training style but at a high level if you do have the ability to hold a more constant interval its better training :thinking:

Quality-wise, doing such long, steady workouts indoors is going to be much, much better, especially if you don’t have any suitable roads nearby.

Not when you are changing power as well. During my trainer rides I often use changes in cadence to break the monotony and make it easier for me to keep track how much time I have left. So for example, on this week’s 3x20x30 seconds at VO2max, my typical cadence was 107–117 rpm, but every fifth interval I’d do it at 90–95 rpm. During sweet spot intervals, I do the same.

But when you are just changing cadence, because your power fluctuates wildly, I think this is a bad idea.

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While I agree with this, I think you can and should practice pacing on different days. I prefer to substitute my weekend workouts for e. g. a “pacing workout”. Last year, I went out specifically to work on different pacing strategies. Once, I wanted to be close to 90ish % on average, so I was a little above that for climbs and a little below that for descents (when possible and safe). My average speed that day was great, even if I didn’t get any PRs that day. (That’s tricky, if I don’t set myself goals for outside rides, I am always tempted to snag up a PR.) Other days when the wind is very gusty, I try being steady. And yet other days, I try to stay in Z2 even on the climbs.

But overall, I don’t like to mix “muscle” drills with outdoors skill drills.

I’m a fan of doing these outside and learning to control power. Don’t overthink it and allow for some zone flex while learning to read the road.


one other thing you can do: for outside days, don’t try to do something that requires a level of precision that you can’t achieve. Rather, try something like, see how many minute at sweet spot (or tempo) you can accumulate during a long ride. You ride to the power when the terrain allows, not when it doesn’t, but that’s okay. More like variable intervals, a different workout. But you’re not trying to put the square peg in the round hole.

One thing I did to try to get better at holding a constant power outside for tempo/SS type workouts was to intentionally start not looking at the head unit for periods of time. After I’d done a bunch of outdoor intervals I would say “I’m gonna ride to that next sign (or whatever is 30s-2m up the road) and then check my power” Then I would try to hold steady power and when I reached that target I would look at the computer and see how close to target I was. It helped me to really dial in my RPE to the appropriate target without constant feedback from my computer.


I’ve seen it mentioned a few times now that the quality will go down if the power varies and that inherently makes outdoor sweetspot work less usefull. While I won’t totally disagree with that statement I would note that the physiological adaptions we are after overlap in zones 2-5

So some variation is fine if you can limit the coasting and the sprinting by appropriate gear selection and shifting as well as being able to make power at a wide range of cadences.

When I was doing a lot of indoor workouts in Erg, telling myself it was higher quality was reassuring. As you pointed out, adaptations span zones or as I like to say “our bodies are not robots.” Going back to outside workouts has convinced me that quality is in the eye of the beholder.


I tried the same intervals but at low cadence. That was actually a little easier to execute.

Next I tried the same interval but just tried to keep the lap average at the target power. I didn’t worry about going over threshold while cresting hills or lower power on downhills. This was more like normal riding except for trying to hit an average power.