12 Comments

1. 

   John on October 25, 2012 at 8:41 am

   This tool is awesome – takes roughly 4 seconds 🙂

   When I enter my data; 158lbs, Male, 800 foot elevation, and riding 4 times a week = the chart shows I what I’ve come to believe as my FTP – which has been 250ish watts – as being the low end of Stages’ Zone 4. We would love to see your results as well.

2. 

   Jennifer Ashbrook on October 25, 2012 at 11:18 am

   Personally, I am not a fan of these kinds of mathematical models. IMO, this is sort of like the power training equivalent of using 220-age for setting heart rate training zones. FWIW, when I plugged my data into the estimator, the FTP estimate it gave me was well off of my FTP based on the standard 20 min test. And it wasn’t just a little bit off, it was WAY off. There’s no way I would be hitting power targets in training if I tried to use this tool to estimate my power zones…

   There are just too many variables that might affect an individual’s FTP beyond age, gender, altitude, and number of rides per week.

   I’m not totally convinced that it’s all that necessary for your average IDC participant to know their FTP. It would be equally (maybe more) valuable to have students note their average wattage at VT1 and VT2, as you might do for heart rate training. With proper training, their power averages at VT1 & VT2 should improve over time, allowing them to track improvement without ever knowing their FTP.

   But basing training levels on an inaccurate mathematical model could lead to frustration and ineffective training for riders trying to stick to zones that aren’t accurate for them.

3. 

   Chuck Cali on October 25, 2012 at 11:36 am

   For the record, when we figure out a way to get our riders actually wearing HRM then we can do ventilatory threshold testing. Alas that has so far been a losing battle.

   Normalizing power to weight is not a shot in the dark like 220 – age. The beauty of power in this context is that it is already on the bike when our riders arrive. Giving our riders a place to start is a good idea that is easily modified by having them try to hold that calculated number for 20 minutes.

   Also let us not for get that Friel is referring (and think Cameron took her numbers from Friel’s book) the expensive power meters installed on outdoor bikes that measure power differently than Keiser, Schwinn and FreeMotion.

4. 

   Chuck Cali on October 25, 2012 at 11:48 am

   correction I think I may have offended the free motion people with my mention of how they measure power. My apologies. FreeMotion does measure power more like and outdoor meter does, at the pedal.

5. 

   Jennifer Ashbrook on October 25, 2012 at 11:53 am

   It may not be a shot in the dark, but as I said, FOR ME, the estimate was WAAYYY off and would be completely useless for training (I’m talking > 25% off). There is no way I could hold the predicted FTP for 20 minutes… I would be lucky to hold it for five. I suspect there may be some gender bias in the model. My point about VT1 & VT2 is that you can essentially use RPE (how the rider FEELS at a given level of effort) to set power zones without doing a 20 min FTP test. No heart rate monitor required… Noting power level when things start to feel hard is, IMO, more valid starting point than a mathematical model. And your point about different power meters measuring and reporting power differently is one of the (many) reasons I’m not fond of this kind of model. It’s better to set your zones based on real life effort on the actual equipment you’re using to train.

   My 2 cents, anyway… 😉

6. 

   Jennifer Ashbrook on October 25, 2012 at 12:09 pm

   p.s. Just for fun, I plugged the estimate the calculator gave me into a power:weight calculator, and the estimated FTP would give me a P:W ratio of about 3.5 w/kg – which would put me right on the borderline of riding at the low Cat 2/high Cat 3 equivalent. I’m not a bad rider, but I’m certainly not Cat 2 caliber…

7. 

   John on October 25, 2012 at 12:16 pm

   This feedback is excellent! Keep it coming 🙂

   FYI Cameron is somewhere over the Atlantic right now, on her way to South Africa. I’m guessing that she’ll jump in here once she can.

   Additional random comment – I’m watching the first snow of the season here in Minnesota… not sure if that’s good or bad for this to occur so early. I’ll never forget carrying my then 1 year old daughter Abby through the 30″ Halloween snow we got in 1991.

8. 

   Chuck Cali on October 25, 2012 at 2:48 pm

   Jennifer,

   Good discussion here which does segue nicely into my post ‘A good reason to come back’. Our riders skills as well as their reasons for being there are diverse. However, in the grand scheme of happy customers (even if our personal numbers don’t jive with the predicted) versus effective training I think a point to consider is that our leadership – even in an arena we are skeptical about – may interest some of your riders. Hence giving them a good reason to come back.

   There is no doubt that for some, training to achieve better results can be more than they’re looking for, which is why every class is NOT about just power or heart rate or perceived exertion.

   Jim said it best, teach the bike. Today our bikes (indoor and out) are far more capable allowing us the flexibility to add some quantitative classes.

   Thanks for your candor. I’m with John here, great feed back.

9. 

   Jennifer Ashbrook on October 26, 2012 at 5:27 am

   Just another thought – it also occurs to me that Friel’s model is probably based on “athletes”, and not folks just out to get some cardio exercise on a bike that goes nowhere. As such, I suspect it may over-estimate FTP for many of our participants. Personally, especially for folks starting out, I would prefer to err on the side of UNDER-estimating FTP. If the FTP estimate is too high, then the new rider will find they can’t hit those “targets”, and will think “well, I just suck at this…”, be discouraged, and maybe never come back. Perhaps some kind of power:weight based formula might work, but with more forgiving factors for age, gender, and fitness level. Of course, that would assume that folks are honest about all of those variables in plugging their numbers into the formula…

10. 

    John on October 26, 2012 at 10:15 am

    Jennifer that’s my concern as well = our desire to “crowd source” this to understand if it’s applicable at some level to our “Club Athletes” as I call them.

    As Cameron explained in the Podcast, our goal as Instructors is to communicate in multiple ways so we will be heard by our students who “hear” very differently from one another.

    As an example:
    My experiences with attempting to communicate VT2 (AT/LT/ Threshold) based on breathing falls short for some students who confuse the initial change they feel crossing VT1 = a perception that they are at VT2 – when they’re not.

    Adding additional points of reference like discussing the existence of VT1 and the feelings that accompany it (which is ignored by almost everyone) can help a student.

    So I see great value in having a way to identify a ballpark range (that’s adjusted for weight, gender and general fitness level) but I completely agree that it needs to be realistic. Best I can tell the only way we will get there is by sampling our demographic.

11. 

    Cameron Chinatti on November 8, 2012 at 3:07 pm

    Woohoo! This is great, gang! Finally, back from a whirlwind trip across the pond and beyond. 25,000 miles in 12 days — not bad if I do say so myself 😉

    Jennifer, Chuck and John – thank you so much for your very insightful comments.

    Jennifer, you should most definitely consider purchasing Joe’s e-book (since I know you’re a data junky!). Primarily, because it does address the short-comings of the estimated power calculations. One of the big culprits is upper vs. lower body lean mass. In fact, I did a little experimentation with this and found it to have a substantial effect. Individuals with more of their lean mass in their upper body (I tested this on a body builder that attends my class for his warm-up and cool-down) are going to see numbers that are skewed significantly on the high-side. On the flip side, the Stages R&D team (Male Category 1 & 2 cyclists) found that their estimated numbers were all lower than their actual FTP. So clearly it’s not perfect…

    But as Chuck so eloquently mentioned, “Normalizing power to weight is not a shot in the dark like 220 — age. The beauty of power in this context is that it is already on the bike when our riders arrive.” He is spot on. Even if this estimate is not “accurate” per se, what it does do is provide a frame of reference that, for the most part, doesn’t even exist yet with power in the great indoors.

    During our Stages trainings I jokingly mention, that the day that Shape magazine starts talking about increasing sustainable wattage in time for bikini season, will be the day I can start my career as a pearl diver (yes, I think that would be fun!). The reason I bring this up is because we’re still just attempting to get people to even care about power output in the first place.

    My travels this last week took me from South Africa, to Dubai and eventually winding up in Dublin, Ireland. While in Dublin I experimented with implementing this power estimate during a short 3-hour session that we have been doing consistently over the last 2 years. 3 hours is NOT enough time to get people to understand the gold-mine attached to their handlebars. So I decided to show them the estimate and see what happens. After doing their calculations for them, and writing their various zones on their Power Post card, they had (for the first time) something to refer back to. At the conclusion of our exploratory ride, I explained to them that in our Stages long course, we actually figure out their personal power prescription with a very specific ride (FTP). This most definitely peaked their interest and witnessed the lightbulbs go on in a major way.

    Perhaps this is because my Irish students were absolutely brilliant, but it is my opinion that this is just one more method to get our feet in the proverbial door. At the end of the day, we’re just trying to get people to use their investment (the power consoles that they paid extra for) wisely and consistently.

    So all that to say, please share this with your students see if it’s realistic and more importantly see if it gets them to explore this “new” language of training with power 🙂

12. 

    Shala Grogan on February 24, 2013 at 10:38 pm

    Interesting. I tried it. The estimate gave me 223 and the first measurement (during our stages training) was 154. I thought my 154 number was pretty good. Now I feel kind of like a power loser!

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