Seven Gravel - IF of .89 for 6hrs - big diesel or wrong FTP or other?

In May I completed my first race, a UCI gravel WC qualifier called Seven in Western Australia. It’s a brute of a race, 126km and a little over 3000m of climbing. Somehow I managed to finish and maintain an IF of .89 for the 6hrs and 19min it took to complete. Trying to figure out what this means in terms of future performance/expectations and set appropriate training. A few details about where I am at in my cycling experience.

  • Recently got back into cycling three years ago, mostly MTB, started road biking about 18 months ago and have been using TrainerRoad for about 12 months. Currently 48. I don’t necessarily come from an endurance background (mainly ice hockey when I was younger and MTB for fun)

  • Since getting on to TR I have stuck to a LV plan trying out different plans, I do my three structured rides Monday, Wednesday and Friday. Weekends I am outside, road, MTB, gravel. Usually between 8 to 11hrs a week. Getting better at staying in Z2 for weekend rides.

  • In the first 6 months of TR I had a 25W bump in FTP but was stagnant pretty much through to the race, post race I dipped by 5W and switched to trying to focus on a bigger aerobic base and now back up 8w to my peak FTP according to AIFTP of 288. I rarely fail TR plan workouts especially now that I have toned down intensity of weekend rides (although they are longer) but definitely have some hard workouts.

With the weather of late I have been doing more of my weekend rides (Z2) indoors and wonder if that’s the reason behind the FTP bump. I am also curious if it’s realistic to have an IF for that long or if it’s really suggesting that my FTP is higher.

Appreciate the wisdom and perspectives of those who have been down this road before

0.89IF over 6 and a bit hours would be well outside the norm I would think.

You’re either an exceptional talent at tolerating just below Threshold, or more likely, you’re due an FTP bump.

Could be many things, maybe fatigue was masking your gains?

What sort of Threshold workouts did you get up to that were challenging, but doable?

I find when I am in a sweet spot block that over and unders where the over is 90 to 120s can be challenging. The last threshold that was tough was Picket Guard

The weekend prior to the race I did a 4.5hr road ride at 0.92IF. A couple of weekends ago I did a 4.5hr @ 0.81 on Saturday and a 3.5hr at 0.83 on Sunday, mind you that was at the end of a block and I knew I had a recovery week to recoup. That said the Friday before the above was Mesachi +5 which was well within my wheel house.

Perhaps Adaptive Training isn’t yet able to give credit to these bigger unstructured weekend rides (although I am doing more to keep in Z2 ish)

Well, what does FTP estimation say?

I have been using the TR AI FTP in all the IF calculations. At the time of the race it was roughly 285.

Another possibility would be differences in power measurement on the trainer, and on the bike. How are you measuring power in each situation?

Also, cooling? Underpowered fans indoors may mean you can produce more power outside than inside.

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Great points @mcalista, I have compared my trainer power to my crank power a couple of times and it’s within 1%. That said one reason I haven’t paired it is my outside power is one sided only and of course that might introduce some variability. (what TR and what Garmin think is my FTP is pretty darn close)

I hear you on the cooling, definitely notice a difference RPE with temperature but does anyone not? I did invest in a new fan and it has been a lot cooler here this winter which maybe is contributing to the recent hero numbers.

Do you feel completely destroyed after all of these long .80 - .92IF rides?

There is either a large discrepancy between your indoor power and outdoor power meters or your ftp is too low. Unless you had a bunch of sprinting and huge power surges, it is very unlikely your IF would be above .85 for a 4hr plus ride (thinking of the .92 4-hour road ride there). I don’t think it’s possible to hold .89 for 6 hour. That all said, you must be under testing on your ftp test (ie the denominator of IF calculation is too small).
I’d recommend you do a 20min test on the trainer setting wattage to 305 and see how you fare

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I agree with KWcycling. I think you are someone that doesn’t do well at short power relative to your ability at long power, so it’s throwing off your numbers. It’s generally considered that for 6 hours you should only be able to manage an IF of roughly 0.70 to 0.75, maybe as high as 0.80, so your real FTP is probably around 330-360 W.

Try the longer (20 min) test at a higher FTP and see if you can manage it. Your actual FTP is generally considered to be 95% of your highest possible 20 min power. Remember that you’re supposed to feel desperate to stop at the end of the 20 minutes. If not, test again another day at a higher wattage. My suggestion of the first try would be 320W.


Like all the others, I am very skeptical you did 0.89 IF for 6 hours. Just in terms of energy systems that seems super unlikely (the longer the more fat you need to burn). I reckon your FTP is underestimated by about 20–27 % = 0.89/0.70. That is bad, because e. g. sweet spot and threshold workouts will be tempo workouts.

You wrote that AI FTP estimated your FTP, does that mean you never did a ramp test? And what is your cooling situation on the trainer? Most people have multiple fans. In the summer (= hot and humid where I live) I also need to turn on the AC. If I don’t, I will crap out through no fault of my own. Even with the AC running, I sweat buckets in the summer.

How much did normalized power differ from average power? I don’t think it’s likely that this was some kind of ‘NP-busting’ ride, but that could play into this as well.
Thinking about the steady-state case, where average power == normalized power, I can’t imagine someone being able to hold 89% of their FTP for 6 hours straight.
Can people really do a 6 hour sweetspot interval? Or is normalized power making this the wrong comparison?
(I will admit, I am a bit of a NP ‘skeptic’, as I fee like it’s really an educated back-of-the-napkin estimate that is taken way too seriously and as a result compromises all the metrics that it is baked into.)

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Post your average power and Normalized power for those 4.5 and 6 hour rides you mentioned. Also, note if there was any significant stop time.

It’s true that if AP and NP differ too much, NP becomes less representative.

You mention that you’ve been posting “hero numbers” lately with improved cooling and cooler weather. That actually points to your old numbers being handicapped and your FTP being higher than estimated.

You might want to try and see what it estimates your FTP at.

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@Craig_G, no not really. I am tired but I can do them back to back and still tackle the structured workouts on the trainer during the week. I was pretty destroyed after the race but that’s because I suffered some cramping I think. An example of two weekends prior to the race, Wednesday was Warlow +2, Friday (1.5hr threshold over under), Friday was Grassy Ridge (VO2 max), Saturday 2hrs outside, IF .96 TSS 195, Sunday 4hrs outside, IF .88, TSS 316, then rolled into Upper Park on Monday and Leconte on Wednesday… etc.

@KWcycling @huges84 @OreoCookie appreciate the perspectives and recommendation to try the 20min test. I was doing a ramp test before AIFTP but haven’t ever tried the 20min version. I do get the sense that I might have a bugger en

Post race I have been working on mostly SSB low volume and trying to stick to that and can pretty easily complete each of the 1hr workouts where the time at sweat spot is roughly 50min @92% and could keep going. Not sure how those are supposed to feel post but perhaps an indicator that the FTP set too low.

As for heat, yep, it’s a factor on the trainer, I have one big kick ass fan but maybe need two, especially in the Perth summer. That said I try to do my trainer sessions first thing but it can still be hot in the garage.

@huges84 A little more detail on those rides

  • Race 6hrs. 5mins moving time, IF .899, NP 252, average power 203, TSS 479. There was a lot of up and down in the race though, a little over 3000m which maybe why NP and average are not close. (and gearing, on the ups I was at threshold more or less the whole time) fueling about 90g/hr

  • 4hr 37min ride, IF .92, NP 260, average power 228, tss 387 - fueling about 80g/hr

  • Last weekend did a 5hr 31min, IF .77, NP223, average power 180, TSS 332. This felt really good, purposely tried to have a negative split - fueling 60g/hr

I’ll have a look at, thanks for your time and perspective.

Any disadvantages by using my bike power meter to drive the TR workouts? I have done some work to see how much variability there is between the 4iiii and the Wahoo and they seemed to be reasonably close, certainly not out by 20 to 40watts but maybe i need to try again.

On the longer efforts I have been using both HR and power as I try to stay in a Z2 level of riding and there does seem to be in the same ballpark both indoors and outdoors at least at the moment but cooling isn’t a problem indoors at the moment.

I appreciate all the TR wisdom and experience, I am not really chasing the FTP but as @OreoCookie says if I don’t have it set right I am not getting the most out of structured rides.

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One thing to look for in particular is whether there are some differences over the power curve - differences in L/R balance at different power levels is the one area where SS PM’s can be misleading. You could well be 50/50 at z2/tempo, but as fatigue catches up, you might be 48/52 at threshold 3 hours into a ride.

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^ I was going to post this as well.

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Those are some pretty big differences in average vs normalized power, that’s why you’re getting a high IF over that long of a time. Lots of hard efforts with lots of recovery time in those rides, but it’s not exhausting in the same way that holding a constant 250W (assuming 285W FTP) is for several hours without a break.

A couple examples of dieseling along at sweetspot :slightly_smiling_face:
Trainer ride with 90 minutes at 89-90%

Outdoor ride in the rain and cold with 2 hours at 88%:

Compare that to a ~3 hr race, where you have lots of efforts with recovery, but also end up with an IF of 88% overall. Still tired at the end, but it’s different from a long, sustained interval.

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