Interval training on varying terrain

I live where the roads are constantly rolling. Even on the “flattest” roads or those with long hills, the pitch varies +/- 2% around the average pitch within every mile. So when doing intervals like 4x10 sweet spot, I can produce NP and average power for each interval at sweet spot but the total time in sweet spot is more like 20 mins vs. 40 mins. As you might expect, I’m also racking up a fair amount of Zone 3, 4, and 5 time in each interval when I go below or above (or overlap) the sweet spot zone on this rolling terrain. I shift a lot to try to keep in the sweet spot but can’t seem to get more than half the time in the zone on this terrain. I’ve been doing structured training for years and ride the roads with the least amount of undulations within range of me. Short of doing these intervals on a smart trainer, any better way to get more time in sweet spot on this kind of terrain? Does it matter if the NP and average power for the intervals are on target?

Hey @steve2!
Is the 20 vs 40 minutes based on average power or normalized power?

We recommend using normalized power and manual analysis for segments lasting 8-20+ minutes when you are riding on rolling terrain. If the normalized power falls between 84 -97% of your FTP then yes, you are hitting your sweet spot!

Another thing you can do is adjust your garmin/wahoo to show rolling power average for 3 seconds. This will make it to show a reading that is not as sporadic and more indicative of the actual zone you are holding.

Here is a podcast of ours that you might find helpful too!


Lacey, Thanks. Both my NP and Average power are in the sweet spot for each 10 minute interval but the total amount of time I’m in the sweet spot range is only half the interval time. So doing 4x10 sweet spot intervals, even though my NP and average power is in the sweet spot for each interval, instead of having nearly 40 minutes in the sweet spot as I would if I were on a dead flat road or consistent 1% uphil or smart trainer in ERG mode, because of the road undulations where I ride, I’m only getting about 20 of the 40 minutes in the sweet spot, the rest being below 84% or above 97%. So what’s the effect of that on the effectiveness of my training, adaptations, etc. Does it provide less training benefit than if I were getting more time in the sweet spot range yet still producing the same sweet spot NP and AP for each interval? And if so, what do you recommend I do about it, short of moving?

this is not true - you are getting in the work - the ‘time spent in zones’ bins is misleading in this way.

So, in the extreme, if I spent roughly half of each interval above 97% and half below 84% such that I never spent any time in sweet spot (other than going between above and below it) but my NP and AP for each interval was firmly in the sweet spot zone, that’d be just as good for my training as would be spending all my time for each interval only in the sweet spot range? If so, please help me understand why it would.