Shayne

Did an indoor TT yesterday. I don't have power on my bike yet but will in the next week or so. The TT was done on Compu-trainers and my avg. watts were 369 for 15:07. Is there a rule of thump guesstimate for getting ftp from this effort. I've done these indoor TT's in the past and the 369 watts matches up well with those efforts.

I was just wondering.



Thanks
Shayne

johnybutts

Shayne, please tell me you weight like 400 lbs?

You can always estimate your FTP to give you a ballpark from a 15 minute effort. Though, you'll almost always be more accurate the longer your effort is (up to an hour I guess).

When you get your power-meter next week ride around for a few days, then hammer a 20 minute effort, multiply by 0.95 and that'll be a reasonable estimate of your FTP. Also get the book "Training and Racing with a Power Meter" by Hunter Allen and Andy Coagen (sp?).

Additionally... there's an ongoing post about training with power, meant for people who have just started power training, check it out, a lot of answers/questions will be addressed in that thread.

waterrockets 

It depends on your anaerobic work capacity. If you have higher AWC, then your FTP will be further from that number.

My AWC screws up my FTP test estimates to no end. When I've done an 18' TT at 368W in the past, my FTP has been ~340W.

merlinextraligh

The CTS field test takes 92% of an 8 minute effort. I've seen 95% suggested for 20 minute efforts. So something between 92-95% would be in the ballpark.

johnybutts

waterrockets... you realize with your 0.95 estimate on that 18 min effort is only about 2.5% off from your real FTP value. Seem that the magic number for 18 minutes is 0.935 for you, not quite as dramatic as you put it, especially considering it was an 18 min effort not 20 you expect to take lower than 95%.

waterrockets 

Yeah, that's true, it's not a huge difference outside the normal scale. Same with MAP tests, I'm just at the bottom of the scale on these things.

Shayne

Thanks for the comments.

Yes, I'm a big dude. 6'-4" up to 210 lbs right now. I'll trim down to the mid 190's for race season, going to put a big effort into weight control over the next year to slowly get down into the 180's. Just did a BodPod test and it was a wooping 18% bf.

Also, just got my Racing and Training with Power book on Saturday. SRM is replacing the batteries in a used setup that I just bought. I'm a new cat 3 and it seemed to make sense to jump to power now.

Thanks again.

Bullseye

Good deal. Since you are bigger/stronger, I'm going to guess that a traditional FTP estimate from 15 minutes will be a bit higher [more anaerobic] than a full 60 minute test would yield, so keep that in mind.

-bullseye

Shayne

Ok, that makes sence. I do turn myself inside out on these things. It's the national 10k course. A mistake I see a lot of guys make, is to go at the same level as a local 10 mile TT. I think you can go harder because it's shorter. I went at a pretty good pace for 2 min., got my HR up to about 6-8 beats over what I normally TT at. Then checked my avg. watts, it was 365 at that point. For the rest of the race I targeted 370, weather going up or down. Then gave it all I had left for the last 2-3 min. to end with a 369 avg. Results just came out and I was good for 1st out of 50.

DanielS

You could do a 3 minute test and then use the results of that, and the results of your 15 minute test, to calculate your Critical Power (CP). This will take into account the effect of AWC. Look it up in the Allen & Coggan book. CP is a good estimate of FTP, as I understand.

cat4ever

Oh great, you're getting a power meter. Crap for me.
Nice job yesterday!

cat4ever

Okay, now with a relevant post. My 15 minute highs are +/- 40 watts over my 50+ minute highs in time trials. That's comparing the 10k time trials to the 40k's I've done.

Shayne

Ha, gotta do something to keep with these guys in the old man age group. Don't worry, I'll save you spot next to me on the crying bench.

Enthalpic

Let me save you guys some keystrokes while venting a pet peeve.

If you want to symbolically say approximately use the ~ symbol. +/- requires more keystrokes and means something else entirely (the standard error of the measurement).

fly:yes/land:no

monster. how close were you to the course record?

crispy010

I hate you already





joke, it's a joke... geez

ldesfor1@ithaca

if I were you, I'd set FTP @ 345 and go from there.

I'm a similar size (6'3.5", 194) with similar power output....

just an educated guess.

ldesfor1@ithaca

oh, and nice to have another big diesel to motivate me this winter. thanks!

umd

Just because someone is "bigger and stronger" does not mean that they would have more anaerobic capacity, it just means their bigger would be bigger in general. You could have a tiny guy that has a large contribution from anaerobic capacity in a 15 minute effort, and just has very lower power numbers overall.

The monod method uses multiple tests over different durations to determine the extent at which the anaerobic capacity contributes to the effort, rather than doing a single fixed effort and assuming some universal multiplier (e.g. 95% of 20min)

Shayne

No one around here's been under 15:00 so that's the goal. There's one of these a month, 4 total so 3 more chances. I know of at least 2 others that have the same goal. I was happy to be 3 seconds faster than my best from last year, on the first event. Since it's a standard course, I'm sure the record is smoking fast. I heard someone was around 13:30 but it was just benchracing talk.


The monod method uses multiple tests over different durations to determine the extent at which the anaerobic capacity contributes to the effort, rather than doing a single fixed effort and assuming some universal multiplier (e.g. 95% of 20min)

Interesting. How much effort should go into testing for ftp? Does WKO+ need a perfect number or is it ok to be off by a few watts? I guessing you get a feel for it after awhile, but that's just a guess.

oh, and nice to have another big diesel to motivate me this winter. thanks!

We get to shine in these indoor tt's. We can make watts, yet have the same frontal area as everyone else.

procrit

You can be off a few watts and it'll be fine. And yes, 340-350 watts sounds like a good place to start.

cslone

Man, I'm so much more aero than you.

Nice job over there!

ldesfor1@ithaca

i wish we did... i got's too much frontal area.

but yeah, the Indoor TT circuit and I are friends.

NomadVW 

Whassup?! I'm big @ 6'2"!

As to the original question: FTP from 15 minute effort, no.

Any FTP estimate you make will need to take into account longer/shorter intervals, either establishing AWC (ala Monod) or accounting for AWC (long interval, MAP testing, or blow out efforts ala CTS)

ldesfor1@ithaca

Nomad, you know that I quiver in fear of your FTP! just post a bit more and I'll train harder.... but until you weigh 185, your w/kg still is rediculously far out of my reach.... offering an unrealistic goal.



-L