Lighter. Lower FTP. Lower W/kg. But faster? I don’t get it

Hey Everybody.

Has anybody an explanation? I’m lighter than last year but my ftp dropped too. My w/kg was last year much better. But I was in my A-race half an hour faster (3:25 instead of 3:50). The long climb took me 10 minutes less (40 instead of 50m).

I don’t get it. And my doubts about the ftp test are back. :face_with_monocle::neutral_face:

You’re fitter. No black magic. Just because someone’s W/kg is higher, doesn’t mean they’re faster. Sounds likes you’ve improved on your sustained aerobic power for climbing, plus any other environmental factors that are impossible to quantify (wind, draft, group dynamics, confidence, familiarity, etc). Good job :+1:t3:


Fitness is interesting.

For other considerations, you don’t mention any condition similarities or differences.

  • Things like wind, temperature, humidity can really impact a person’s results.
  • Add to that the group dynamic (if present) where you may be drafting.
  • Or even without drafting, the presence of a rabbit or other motivation can lead to huge variations.
  • Mindset and your anticipation of the event can also impact. Maybe you knew the course better and anticipated a better power delivery on the 2nd attempt. Pacing and such, especially on a repeat event can make massive differences in results.
  • Equipment changes to the better should be considered.

All these aren’t meant as answers, but sparks for you to consider the many, many other things that may lead to the differences you saw.


How much lighter? How long/steep is the climb? Temperature/wind differences compared to last year?

Chopping 10 minutes off a 50 minute climb is enough to have me wondering if there is a device calibration issue. A waxed chain and a fast rolling tire isn’t going to get you 10 minutes on a climb!


How much time did you spend at or near FTP? Your LT1/AeT/Z2 could be significantly higher after another year of training. FTP is but one measure, and depending on your testing may not reflect fully on your capabilities. Your anaerobic power may be down but your aerobic power may be up and contributing more.

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Sounds like you either raced smarter this time or your current power profile isn’t accurate. If you have both times you raced it uploaded, you should be able to zoom in on that segment and make a direct comparison in terms of power/pacing/heart rate.

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FTP alone means nothing unless you are running at actual FTP. And that means measuring FTP not estimating. Aside from that all is to be said is congrats. You earned results!

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That’s right. I should have mentioned this. Nearly everything is the same or similar. But especially the climb was nearly 1:1.

I will post the strava file later, but I have found something remarkable about the FTP test. :arrow_down:

I did a FTP ramp test again. Yesterday, one day after the first one.

50 watts more.

The difference? The selected gear. The first one was on the small ring and on a smaller gear in the back. The second one on the big ring an and a bigger gear in the back. (To avoid chain crossing)
Both erg mode.

My opinion: the faster spinning flywheel has more momentum and bridges little weaknesses better than a slow wheel. You know what I mean?

So if you get into an overtraining or you stimulus is to little depends fully on your daily gear selection.
@Nate_Pearson @chad


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This is nothing new. What you found is the difference between high and low inertia. It has been discussed here ad nauseam. Feel free to use the search function. In summary:

Riding in the small ring and mid-cassette (straight chainline) will give you low inertia. This is like clmbing. Riding in the big ring and mid-cassette (straight chainline) is high inertia. They do feel different especially the higher the wattage.

Again, search function is your friend, keyword “inertia”

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Thanks. didn’t know that it was so obvious and there is no info from TrainerRoad itself.

I think the likely explanation is:

FTP is just a single data point along your Power Duration Curve (regardless of whether you do the Ramp Test, 20min, etc.). A race, particularly one lasting longer than an hour, and depending on the terrain, may require high power and high fatigue resistance at several points along the PDC, both sub-threshold and supra-threshold. Last year, for example (prior to joining TR), my training focus was on 10kft GFs. So while my FTP dropped 7%, my 6hr power increased by 28%.

If you really want to compare to your power year over year, you should do power profile checks when you do FTP tests (see p.43 of the new edition of Training and Racing with a Power Meter by Allen, Coggan & McGregor). If you use WK04, Time to Exhaustion (TTE), Functional Reserve Capacity (FRC) and Stamina are also important metrics to track (also described in the book and on Training Peaks website).

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Generally speaking, if you’re training in ERG mode, you’re going to pick a gear and leave it there. Even if the bike goes outside every so often, chances are you’ll put the bike back on the turbo and use the same gear again. We are creatures of habit.

I ride the turbo in ERG mode in the small ring. I never put it in the big ring. Why? For one, it’s quieter. Secondly, it feels harder. Lastly, it’s mountainous here! When I go outside, I have no problems putting out the same power in either ring on the flats or climbs. <-- This may vary for many others. If I were to prep for a flat or mostly flat TT, I would probably do some specific ERG training in the big ring.

Do not overthink this. If you’re going to use ERG mode. Pick a gearing. Do your FTP test in said gearing. Then do your training in the same gearing.


I always wanted to do a power profile and exhausting test. But time is money. :wink::grin:

50W is a huge difference though. And if anything isn’t it easier to push high watts when there is higher inertia (I.e. large ring), which is the opposite of what happened here? Certainly most people find they can push more watts going uphill than on the flat.

You have it backwards.

High intertia - big chainring
Low intertia - small chainring

Think about the speed of the flywheel when in the big chainring vs the small chainring for the same exact wattage. It is much faster (hence more inertia) in the big chainring and thus louder, even on the new Kickr or a Neo.

This is another can of worms for a different discussion/thread. Actually, probably been discussed here before.

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btw: even without doing power profiling, etc, since you raced it last year you could compare the training block prior to the race (e.g. prior 120 days) last year to this year for numerous points on the curve. I’m not familiar with TR’s analytics as I am a WK04 user, but perhaps TR analytics will allow you to do that.

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Sorry, need coffee, did know that! Still don’t think that inertia can explain a 50W difference, but the main thing is the OP is faster on the road which is ultimately the objective of all this…

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Yes, you found what many of us feel. Lengthy discussion here.

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