20' power while climbing outdoors - does it correlate to flats?

bmr94539

Rode outside today with my wife and she has the great idea to hit Sierra Rd for the second of the 20' intervals.  It's a steep road and really hard for me to keep the rubber side down at less than 300 watts in a lot of places.  Anyway, after the ride I'm looking at TrainingPeaks and it shows my 20' power at 269 watts average (275 normalized) even thought my FTP on my trainer last time I measured was 223 watts.  Does this just go in the books as overcooking my interval?

Is this all equivalent?  Am I just whimping out in the test and not going as hard as I should?  Does power in the hills equate to power on the trainer or on the flats?  I figured power was just power no matter how you got it done.

I also noticed my cadence was considerably lower (maybe not enough gear inches on my compact crank 50/34 w/23 rear?), somewhere around 40-50 instead of my normal 90-100.

Dino Sarti

Someone who is wicked smart will have the answers you are looking for, but I am of two minds on this. My first thought is that a watt, is a watt, is a watt. If you are going up hill, down hill, or upside down riding on a wire, the PM does not know know this. It is just measuring watts and you are making them.

The other thought is the physiology. Mashing with powerful stokes and a low cadence versus spinning along at higher RPMs. I personally make better power climbing at a low cadence sitting up with my hands near the stem. My cadence is in the 70's and I am nailing it. On the flats, I tend to get more winded spinning at anything above the high 80's. I make good power, but I seem to sustain it better climbing.

Just my n=1....

zwuba

It's quiet normal that most of us will find it "easier" to generate power uphill than on the flats or on the trainer.
Nevertheless Dino got it totally right - A watt is a watt is a watt no matter where on earth you generate it!

As your avg power is that much off your last FTP I would tend to say your FTP must have increased since last test and should no be somewhere around 250W ... but you should do a test to proof it as the cadence was way off what you normally ride.

For the cadence thing - if you are doing high wattages at a very low cadence the effective force that is needed on the pedal is very high. Thus you are more fast-twitch muscle fibers that will also consume much more energy (calories).
When you look at the quadrant analysis of your ride I expect that these 20' will most likely land in quadrant 2 (high force + low cadence).

We as triathletes should always stay in Q3+4 when racing (according to Mr. Coggan and Mr. Allen) so we keep the energy consumption as low as possible

Joe Matchette

Posted By Bryan Richter on 26 Jan 2013 09:44 PM

Rode outside today with my wife and she has the great idea to hit Sierra Rd for the second of the 20' intervals.  It's a steep road and really hard for me to keep the rubber side down at less than 300 watts in a lot of places.  Anyway, after the ride I'm looking at TrainingPeaks and it shows my 20' power at 269 watts average (275 normalized) even thought my FTP on my trainer last time I measured was 223 watts.  Does this just go in the books as overcooking my interval?

Is this all equivalent?  Am I just whimping out in the test and not going as hard as I should?  Does power in the hills equate to power on the trainer or on the flats?  I figured power was just power no matter how you got it done.

Bryan - The big question with reference to this is "what were you doing on the first 20' interval?".  There are a number of ways to estimate FTP: either with a 2x20(2') test and take the Normalized Power for the whole 42minutes, or using the 5/10/20 test and taking 95% of the 20' section.  But these are just estimates...FTP is power output over an hour, so to get the actual number you would have to give it your all for a whole hour.

Overcook? maybe.  But once or twice is OK.  If it is a habit, then you are either digging yourself a hole, or you need to retest.

As Dino and Stefan said, it feels "easier", and I put that in quotes b/c work is work regardless of where it is done, to generate power while climbing.  Even if you keep your cadence at your normal riding power, going uphill makes it easier to work harder.

Finally, FTP testing is both an art and a science.  It can take a few iterations to get a good test.  What do I mean by that?  If you are not 'tongue-in-the-spokes' tired and legs are shaking at the end of the test, you might not have pushed yourself as hard as you are physiologically capable.

Bottom line -- hills are great places to get a lot of work done in a short amount of time.  I live in a mostly flat area and am envious of you who can go nail a 20-30' climb out your backdoor.

robin sarner

 So ftp closer to 260 ?    95% of the interval.

Keith Wick

There are two things of relevance that I see in what you are asking. (1) Your measured FTP was done inside on a trainer instead of outside. For most people you will find your inside/trainer FTP to be about 10-20 watts lower than your outdoor FTP (2) riding hills does make it easier to generate watts as the hill is partially responsible for this generation of power. Yes, a watt is a watt, but on the flats you are 100% responsible for the cranks and power generated, while on a hill the gradient does produce some watts. Think of it this way- when you are riding and going by perceived effort at X amount of watts and then you hit a very slight grade, but keep riding at the same effort you will see this sudden spike in your watts so your PM say X+ some number. The only other way to explain this is to remember the first time you went for a ride with your PM and hit that small incline and your PM gained 60 watts before you could even blink. I think the general rule for a hilly FTP vs flat is to subtract 3-7%.

Oh, and I just thought of a 3rd thing. What was your VI for that 20' segment. Since you mention areas of 300+ watts, it doesn't seem that it was a steady as should be for an FTP type test interval. That may also have something to do with your numbers. Regardless, it sounds like you put in some serious work, but you may want to be cautious about using this n=1 as your power number. After all, even a blind squirrel can find an acorn once in a while.

zwuba

Well as I'm pretty new to the PM business I have to admit I don't have experience on outdoor-tests but as longer as I think about it the less it makes even sense to do it in my opinion.

Even if you have a piece of road without any intersection how could you tell all cars and trucks to not overtake you when you're testing ... not talking about temperature and wind conditions at all.

From my mind everything will have an impact (mostly on your power output variation - VI too high) on your test score.



my 2 cents on FTP testing:

Do the test always and forever in the absolute SAME conditions!!

Al Truscott

I saw Keith's comment, "Hils generate watts" and heard a zen koan. Something which makes no sense, but nonetheless produces useful thought. Here's what flashed through my mind:

• The hill, of course, is not actually adding power to the pedals
• But most of us do sense that generating the same watts up a hill *feels* easier than those watts on the flat.
• So what's different on a hill than on the flat
• At least two things: we're going slower, and we are tilted at a different angle relative to the horizontal.
• Going slower: the biggest impact here is less wind resistence. We know that, @, say, 22 mph, most of our incremental effort is being spent overcoming wind resistence, not gravity, and this resistence, unlike gravity or friction, increases geometrically with speed. So when we're going, say 10 mph up a hill, it takes a lot less effort to speed up to 11 mph than it would to speed up to 24.2 mph (10% faster) on the flat. Since we're always making micro adjustments in speed, our kinesthetic sense knows there's a difference...it's "easier" to generate more speed going up hillcompared to the flat, when starting out at the same watts/joules. Also (much less important), there will be less friction on the tires at a slower speed, as less surface area/unit time is hitting the road.
• Different angle to hborizontal: this is a problem for a Newtonian (Galillean?) physicist. There may be some differences in how effectively power is translated from the legs to the wheel depending on the slope. Picture the chainring, and assume that the most efficient spot to generate power is when the pedal is forward/horizontal on a 0 % slope (flat). Call that 90* [Don't know if this is true, but it doesn't really matter, as we're looking at differences here, not absolutes.] Now assume that on the flats, with a seat tube angle of 80 degrees, that the strongest part of our pedal stroke occurs when the pedal is at 75* (15 degrees above horizontal). Shift the slope by, say, 10 degrees, and that puts the strongest pedaling effort closer to that 90* point on the chain ring ... the hill IS generating more power! Anyone who's ever played with putting the pedals on a tandem in phase or slightly out of phase will have an intuitive feel for this concept.

Anyway, I don't know if either of these ideas is true, but it's what flashed through my brain as I was waiting for my wife @ the Y this AM after our Sunday morning swim.

@ Stefan ... I agree it is risky AND inefficient to do FTP testing outdoors. It's hard to find a good spot. I'm willing to drive 7 miles to get to a road with nice, 12' wide shoulders, little traffic (traverses an Army base) and no lights or stop signs for a 7 mile distance. I do have to make a fdew turns along the way, but it is repeatable and not frightening.

Dino Sarti

@keith - hills are making power?  That makes my brain hurt...



@Al - how does wind resistance change power? It changes speed at a given power, but the meter is in a vacuum. How does the wind resistance impact power measured by a machine at the hub or crank?

this like a zen power discussion. 

bmr94539

 Thanks for all the good thoughts. I'll definitely keep doing my tests on the trainer. I guess I'm going to have to see if I can leave less in the tank on my next test.

Now that the OS is winding to a close, I'll get back to hitting the hills more.  Gotta get ready for Wildflower . 

Al Truscott

Posted By Dino Sarti on 27 Jan 2013 11:45 PM

@keith - hills are making power?  That makes my brain hurt...



@Al - how does wind resistance change power? It changes speed at a given power, but the meter is in a vacuum. How does the wind resistance impact power measured by a machine at the hub or crank?

this like a zen power discussion. 

YES - that was my feeling with Keith's comment, which generated my speculation. No question, the cyclist is the only thing generating power on the bike. No external forces involved. But cycling up a hill may make it easier to generate more incremental power due to less wind resistence against the bike/biker unit @ slower speed for same power output. And having a different set of angles relative to the crank/chainrings may make it possible to generate more power with the same muscular effort. Both of those might contribute to the feeling the it is "easier" to generate a specific power level while going up a hill compared to the flats.

Steve West

I've been waiting for Coach Rich to chime in about FTP on hills. I can't seem to find it (bad search foo) but I remember Coach explaining his method on a local hill he rides often.

I believe he goes there and hammers for 18' to 20' up this hill then takes 7% off the AP to find his FTP. There was some specific reasons he used but I cannot remember any.... Then again, I could be totally mistaken. Wouldn't be the first time.

Coach!.... you out there?

zwuba

No Steve you're right I also read that just a few days ago somewhere here in the WIKI -> http://members.endurancenation.us/Resources/Wiki/tabid/108/Default.aspx?topic=Alternate+Means+of+Determining+FTP

tgarson

@Steve

Coach Rich has described his local hill climb TT in the context of estimating his FTP a bunch of times, but I don't think you're going to get a simple "subtract X %" figure out of him. As far as I've always interpreted it, his point is that he is able to estimate his FTP from this hill climb based on a wealth of experience as a cyclist, he has years and years of riding with power and knows from actual experience rather than a mathematical model what his power for this specific interval means to him.

There are two things I will say on this topic that I think are very important. The first is in support of Rich's point. If you are going to be attempting to measure FTP outside of the conditions in which the mathematical model was validated on (specific power test routines under controlled conditions), then honestly an estimation is going to be just what you get. Whether it is a good estimation or a bad one is going to be something you have to learn from future rides and experience in different conditions.

My second point is that the goal of an FTP test is NOT to produce the highest number possible. The goal of an FTP test should be to produce an number that is as accurate as you need it to be. That last part is key because quite simply, not all FTP's are made alike. If it is the OS and I am going to be using my 'FTP' to do a lot of high intensity indoor intervals at a maximum of 20' in length, then doing an indoor maximal intensity interval at 20' in length is a fantastic way to estimate it.

Now, if I am going to be using my FTP a super long lower-intensity effort, like say an Ironman, and I am basing all of my pacing data off of something like a 20' hill climb than I can tell you right now that is a very risky decision. I challenge nearly anyone to actually go out and ride an hour at their 'FTP' based off of a short-duration, high-intensity test and come back to me with how accurate it is. If you are anything like me, you can barely hold your 'FTP' for 20 minutes, let alone an hour.

So I guess that's where it all comes full circle back to experience. If I know my 'FTP' is probably skewed high then I basically have 2 options. Do a more accurate test that reflects the conditions and equipment in which I am like to race upon, or simply tone down my goal IF to compensate for the fact that I know these numbers are slightly cooked.

I really want to drive that point home though. I know as much as anyone that trying to set new PRs for highest FTP is a fantastic motivator for training and by all means I encourage you to continue to do it. If a hill climb test is what motivates you to work hard, then by all means continue to do it. Just be conscious and cautions when attempting to use that data for pacing actual racing.

Al Truscott

To supplement Trevor's comments ... years ago on this forum a VWSM (LakerFan for the cogniscenti) stated that the best predictor of one's race day IM power is found on the "Mean Maximal Power Curve" in WKO/Training Peaks, looking at the power number at the 5 hour point.  In EN layman's terms, this is basically your NP for a standard race rehearsal.

This concept will become more understandable and relevant as we enter long course race season, and we may come back to it then. But briefly, if EN pacing guidance says you should be riding in and IM @ 69% of your FTP, and your find yourself only able to manage 65% in that final race rehearsal, that probably means (as Trevor is alluding to) that your "true" FTP is a bit lower than the one you were so proud of obtaining on test day. And you may need to Curb Your Enthusiasm on race day. Same thing applies to VDOTs and IM marathon pacing.

rmiller

I was going to chime in earlier, but decided not to because I didn't have any substance to add. However, after seeing Trevor's reply, I decided to chime in in full support of his second point. I think it is a very well said and well reasoned explanation of how to approach training philosophy. Yes, we use FTP to get an estimate, but it is not gospel. I feel like that is a major lesson I've learned over this OS - that these things like FTP, vDOT, VO2, etc - are tools to help us train, but should not always be treated as absolutes.

So, in the OP's case, the 20' segment uphill produces NP of 275, which, based on the 20' FTP test guideline, would result in an FTP of ~260W. The previous FTP test indoors was 223W, but we don't know when that was and how much fitness has improved since that test. So what? If the test that resulted in 223W resulted in FTP workouts that were challenging - who cares what the number was? Especially since EN vets have indicated that their FTP fluctuates throughout the season. If FTP were the be-all-end-all - the goal throughout the training season would be to maintain that FTP number.

Coach Rich

All, great discussion, with special props to Al and Trevor, ie, I think they most accurately capture what's going on here. My notes:

• Very important to understand how accurate your FTP "needs" to be, as a function of what you intend to actually do with it. This time of year, all we're really using it for is to periodically assess your fitness gain and move your wattage targets accordingly. So FTP "high," low, doesn't really matter. Just give yourself a target for intervals and be smart about not cooking yourself.
• As you get closer to the race season your rides will get longer and we'll start to fill out that curve that Al talks about --> you'll dial in your HIM and IM race day wattage as a combation of FTP * IF guidance, augementing this with your demonstrated ability to ride watts X for Y hours. And you'll have a ton more experience with intervals, tests, etc to have a very accurate FTP.
• Yes, for whatever reason, most of us can just put out higher watts on a climb. Seating position, hip angle, cadence, just mentally eaiser to tear yourself apart on a climb vs flats, etc. It just seems easier to disconnect your head from your legs on a climb vs flats. 
• My 7% on my hill is just a number I've found to be accurate over the years. It's also a function of how I personally train: I don't do formal intervals, I do a lot of climbing, etc, so I'm fine with my FTP being more of a "climbing" FTP, as that's the venue that I do 85% of my training in. 

Keith Wick

Posted By Al Truscott on 27 Jan 2013 02:29 PM

I saw Keith's comment, "Hils generate watts" and heard a zen koan. Something which makes no sense, but nonetheless produces useful thought.

 

Yes, that was the point I was making......holy take everything literally, batman!!!!  I admit, that it was not very eloquently thought out comment, but given the discussion I think many of you got what I was saying.  Revoke my WSM if needed