Indoor vs outdoor sweet spot 2x20

I moved last summer to a new area that is very lumpy and rolling. It’s hardly ever flat which makes doing steady state work difficult.

I’ve been 2x20 SST on the trainer and it’s easy. I was even thinking to start progressing to 3x15, 3x20, etc.

The weather was nice so I tried to do the same 2x20 outsides on rolling terrain. It was difficult hitting the power target. I was sometimes hitting 400 watts cresting a hill or 120 watts going down the other side. I did better on the second interval but it was still a challenge to hit the target power. I’m shifting and changing cadence a lot in order to get there.

After the ride, I felt totally worked over. This was much more of a workout than steady state sweet spot on the Kickr!

Is outdoor sweet spot my new secret weapon?

Let me rephrase your question…

  • “Is not following my prescribed workout as closely going to make me faster than following it?”

I am not in the know on that, but just want to share a perspective from an outside view. If there is a goal of hitting a general power target, and you are exceeding or not meeting that (or having wider variation from the goal), that would seem to be “not ideal” or as directed, in my eyes.

I get that you feel more “worked over”, but that is not necessarily a good thing, when looking at the broader picture of your training plan. If it over stress you, to the point of missing on a future workout, or having more fatigue than you can handle and recover, it is a problem, not a “win”.

It may also lead you into different strain or energy systems than intended, which may mean you are missing out, even if you feel like you got more from the effort.

Context matters here, and you have to look wider than the single workout to really see what the impact may or may not be.


I hear ya. I was definitely not trying not to go above threshold during the 2x20 intervals but it was almost impossible in an undulating terrain. I did better on the second interval and I’ll try doing this workout again outside.

I felt like the constantly changing cadence and gearing made it a lot more challenging than being on the trainer. Maybe this is a good thing?

  • No question is it more difficult to nail a workout like that with varied terrain.
  • Again, you have to define what “good” means in this context.

  • Are you looking to learn how to apply even power on varied terrain? If so, then it is potentially a “learning opportunity” as much as a “training session”, which is good if you need that ability.

  • Are you looking to nail power to a target range and keep it tight? Then it is potentially not good, and more detrimental if the choice is between nailing the workout inside vs having more variability outside.

There is no simple answer, because what matters can be very personal, and relate to you and your needs in any event or place you aim to apply your fitness.

  • If the outside workout aligns with your ultimate goals, and the deviation doesn’t hurt you in future workouts, it’s likely ok.
  • However, if it’s different and difficult with no relation to your needs, and you are potentially not hitting the desired training demands, it may be a bad thing.

We can’t answer this for you, at least not without a ton more info. As with so many things in this area… “it depends” is totally true here. There are few absolutes, especially when we get into the weeds a bit here, splitting hairs on training effectiveness. I am no research hound, so maybe there’s hard data on this. But I tend to think (from years reading others commentary on lots of research) that we don’t really “know” this with enough certainty. Much of this boils down to basic principles, and seeing how YOU actually respond to the training and recovery you experience.

In most cases, outside workouts are a compromise. They seldom have the control we get inside, but if you gain other aspects from being outside (the simple joy of actually riding a bike for one) it may be a very worthwhile tradeoff vs doing it inside. You can see several other discussions on the basic pros/cons of inside vs outside workouts in at least a couple of other threads.

But back to your original question / implication… I don’t think you found some holy grail of training here, just discovered a different way to approach a goal, that also has different pros/cons that come along with it.


That’s IMHO the problem with doing long intervals outdoors: at least in my area there are very few routes where I can do a 20-minute long sweet spot or threshold interval. If it is longer than 30, I have to ride for a very long time to get to a long, continuous climb. Shorter intervals are much easier. I have several hills nearby where I can do <= 5-minute intervals and quite a few places where I can safely do sprints.

So I think you should choose your outdoor workouts carefully, and/or adapt the route accordingly. I like to do Z2 workouts outdoors (but choose your route accordingly, I have to avoid all those tasty hills as if they had the plague). But I’ll also do group rides to improve my drafting skills and also practice things like out-of-the-saddle efforts (because the techniques outdoors is different from indoors). Proper sprints should also be practiced outside (make sure you do them in a safe environment!).


All very good points. To expand on this: nailing your power targets is what makes your “muscles” faster. And it is not a good idea to leave the designated power zones.

Learning to pace yourself outdoors and be as efficient as possible can actually mean the opposite. You should learn to use (and mostly conserve) your momentum. For example, on the flats where you have to deal with gusts of wind, this might mean you have to keep your speed/cadence roughly constant and just deal with the change in power. Or it could mean to punch up small hills so as to reduce the loss in speed.

The two are complementary aspects of training, and I wouldn’t want to mix them.


Same bike, same power meter. I never use erg mode.

Bet the overall KJ was higher in the outdoor workout. That and the time in higher zones will have done the damage. Maybe some muscular fatigue from higher and lower cadences than usual too?

Outdoors workouts are great fun but a lot more hassle unless you’re blessed geographically!

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How much variation are we talking about?

Could you share charts, and/or average and normalised power for the intervals?

I am in the same place today. Feel a bit more worked over than I normally do for a 90 min sweet spot workout. This is 15 mins SS with sprint starts.

I was all over the place power wise with it being super windy and rolling terrain. I do think part of mine is that I ride erg mode and had not done a outdoor sweet spot this year yet. Power for each interval ended up pretty dang close to where I was supposed to be though.

So I call today’s ride a win - got outside and did a structured workout.

Here is the 2nd interval. It was actually 25 minutes. I know that I’m occasionally going above threshold which is probably not desirable for a SS interval.

I’ll get better at these as I do them more and keep the power better in check. I was trying to keep power between 185 and 200 watts.

I do think that the varying cadence might add a beneficial training effect. Basically the torque is constantly changing while I’m trying to keep the power the same.

A lot easier to see if you displayed in TR and highlighted SS, or in WKO. I find Strava terrible for reviewing power data.

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Looks like over unders in a random pattern. If your goal with sweet spot is to build muscular endurance and work on lactate clearance, I’d say, this workout helps. Maybe not as good as a more steady target, but not worthless either. Before the age of trainers and locked-in power targets in erg mode, this is the kind of riding people did.

Looks like you rode a loop twice. If you ride the same loop over and over, I bet you’ll get pretty good at anticipating the terrain.

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I think you’ve got it. There are zero long, straight flat roads around here. This is really the flattest course I have around here and it’s undulating. I’ll get better at modulating power. Maybe I should concentrate more on not going over threshold and worry less about power dipping to 120 watts? That will keep most of the workout subthreshold.

I was wondering if the constantly changing cadence is actually a better workout. Or, maybe just different and a different stimulus can sometimes be good or complementary to work on the trainer. I definitely felt like I got a good muscular workout.

I think that’s it. If you’re in rolling terrain use that to your advantage with either this type of steady state work (albeit less than ideal than a steady grade) or focus on some VO2 max intervals. If you have a few 5 min climbs, those are great for that. Riding the trainer is great for efficiency but you lose something when you never ride outside. It’s good you’re experimenting with this, and as you say these outdoor workouts can complement, not replace, your trainer sessions.

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Physiologically I think it’s better to ride these intervals in a steady state fashion, but it’s worth remembering that the vast majority of us are training for outdoor events which aren’t pan flat – so you’re going to need to learn to pace your efforts, even if you do flat TTs.

I recently did some efforts outdoors on the TT bike – it’s tricky but if you aim to keep the power +/- 5% you should be able to keep your VI at 1.00.

I bet the more you do these outdoor efforts the better you’ll get at keeping the power fluctuations tighter

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While I live in the Chicago area where it is predominantly flat, there are some short little risers here and there. It is a learned skill to hold steady power over rolling/uneven terrain, and it sounds like you’re doing a good job of using all the tools at your disposal to do so. Keep working at it and I’m sure you’ll get things down pat.

One thing I’ll note is that holding steady power is not the same as holding speed. So when the road tips up, you’re likely to back off the speed to hold the power level steady. A lot of riders I know have a hard time with this because they want to conserve momentum during outdoor workouts, and more often than not, I’ve found you have to let that go and accept you will be slower up the hills. The bonus is you’ll be faster on the descents to even it out because you’ll be keeping that steady pressure on the pedals, however.

Doing longer efforts of rolling terrain definitely takes practice. It probably isn’t and will never be as precise as indoors but I think it will make you better at outdoor riding if you can get it pretty close. As you do more of these intervals outdoors they will get better. I’ve been doing things outdoors and my interval precision has gotten much better but it has taken deliberate practice and much more checking in on power than when indoors. Here’s a ride from last weekend with some 15-20 min SS efforts.

The intervals are much more defined than what yours looks like. It takes alot of shifting and cadence changing but I have gotten much better at adjusting by feel. I also run an 11-32 cassette with 52-34 chainrings even though I live in a very flat area so that little pitches don’t force me out of my power range.

The last bit is through a more urban area so the power gets messy there.


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!