FTP protocol - accuracy on the open road

Sheila Leard

... sorry if this got posted twice - I'm a newb!!

Protocol: Functional Threshold Power (FTP) Test: time trial for 20' at the best (hardest) effort you can sustain for the full 20'.

Hi Coach - when riding a sustained effort for 20 minutes on the open road I will need to account for turns, slowing for obstacles, variations in road surfaces. Does this affect FTP that much or dont't sweat it.

Other option get in a time trail course that's flat?

Thank you -

Darren Freeman

Hi Sheila, Welcome to EN.

Ideally to perform the FTP test you want to have identical equipment setup and conditions each and every time your perform the test.  If you have the ability to test indoors you should do it inside as you do not have to deal with all the road hazard, wind and weather conditions which you mentioned outside.  Although if you need to test outdoors you should perform the test on the same stretch of very flat road, under the same weather, wind and  traffic conditions each and every time.  

As for translating your indoor FTP numbers to outdoors; the common mantra is your power values will increase because of environmental factors such as more efficient cooling due to wind and maintaining a lower rolling resistant due to an increase in angular momentum of the wheels which makes it easier for you to maintain a certain wattage output.  Ok, enough of being geeky..

The short answer is use the exact same conditions for each and every test and stick to it.

 

bc4ua

To add to her question, what about FTP protocol during half/full training? Is it desireable to still do the test indoors? Or is the wattage you know you can hold during your Sat/Sun long bikes more telling?

TH3 FRB

I'll disagree with some of the above. While a consistent testing protocol is important, we are measuring power output, not something like rolling resistance or aerodynamics where the conditions can have a significant impact on the results. Of course it is desirable to keep everything as similar as possible from test to test within reason. If you are doing the majority of your training inside (OS for example) then test inside. But when the weather turns and you transition your training to primarily outsiode I think it's important to do the same with your testing. The trick here is of course exactly what your original question was all about. You'll need to find a location where you can ride 20min more or less free from interference. Don't worry about variations in road surface, inclines, or wind as long as they aren't extreme. It's really intersections and traffic that can get in your way. Turns are mostly fine as long as you can keep rolling but you definitely don't want to be stopping at a light or sign indefinitely. I test on a long stretch of road where I need to make 2 U-turns to get 20min. My NP drops 1-2W during the 3-5sec that I'm not putting power to the pedals. That's not enough to worry about but anything more and it would start to be a concern. If you absolutely have no options for getting a clean test outside then go ahead and test on the trainer but be aware of the potential differences in inside/outside power output.

Rumpole

Testing is a good test of mental toughness and a good way to get a handle of what FTP feels like. But the most important thing is that the value be repeatable for extended intervals. After a while, you'll know when it's time to bump--either because a 90 min ride came in at 20w over your test value, or because the old 20 min intervals feel too easy. After you train with power for a while, you'll know when to bump your intervals by 5w or so.

tgarson

I've commented pretty extensively on this in the past, and to avoid sounding like a broken record, the answer is yes. Yes to what everyone has said.



Yes you want your tests to be repeatable, and there is some value to doing indoor tests as a very controlled benchmark, but this comes with some pretty big caveats because you have to be able to extrapolate this indoor benchmark to outdoor pacing.

Yes to testing outdoors, in conditions that are as similar to the conditions that you will train, and most importantly race in.

And lastly, a big yes to acknowledging that we are triathletes, no 40k TT specialists. We aren't coming up with these numbers to pace a 60' minute maximal effort (what FTP is actually supposed to represent), but to pace multi-hour triathlon legs that need to be backed up with a solid run.



FTP's serve two major purposes. One is simply as a training benchmark and a motivator to help us set goals, strive for them, achieve them and continue to push ourselves to new levels.



The other major role is for pacing in competition. In this role, FTP is a component of our overall strategy, to be used along with RPE and/or heart rate, to developing a pacing strategy for an event that is validated by the cumulative data from recent rides in similar conditions as the race, including of course, your race rehearsals. Never, ever show up on race day and expect you should be able to ride at some target watts just because a 20 minute test and some formula tells you can without at least some validation that you can in real world conditions.

Sheila Leard

Trevor - thank you for the well thought out response. Your following statement is why I started to train with power

"We aren't coming up with these numbers to pace a 60' minute maximal effort (what FTP is actually supposed to represent), but to pace multi-hour triathlon legs that need to be backed up with a solid run".

Thanks - Sheila

Sheila Leard

Chris - I am learning what FTP feels like. As already mentioned it's easy to slack off when the ability to generate more power is there. Watching the watts keeps me honest.

BTW - is this the Chris Mohr of MohrResults.com ?

Sheila Leard

Joel - some local bike shops host  Time Trials. I can use their course with one u turn. Or better off go do the TT ... the race of truth!

TH3 FRB

Sounds like you have a good option for testing outside - either on your own or the actual time trial.

Pina

@Trevor Nailed it!

My 2 cents adding to Pacing strategy... it comes from cumulative data, not your FTP exclusively. FTP will set your IF and with training you'll learn what IF you can sustain for HIM/IM racing. I here too often that people say "I only held IF of .65" and then when asked about training files most of their long rides outside of intervals were closer to .60. In this case an IF of .65 race day was pretty damn good. If you want to hold .75 you've got to have cumulative data that earns you the right to simply do that. 

A great long ride I repeat preparing for IM is 5x50' (10 min recovery) at .75 to .80. The data will never lie to you. Hope this creates a clearer picture.