More on Estimating FTP

A lot of readers took exception to my suggestion in a recent post that you could get a very rough gauge of your functional threshold power (FTP) based on several variables, the major one being your body weight. This could prove useful if you wanted to set a FTP goal for your bike training.

Someone pointed out to me that there were also contrary comments on other websites such as SlowTwitch.com. (One guy there threatened to throw away all of my books for writing such an extreme piece. I wonder how he deals with topics such as abortion, gun control and the war in Afghanistan. :)

 

I realized that as I was reading these comments that several were made by triathletes. It was hard to tell in many cases, but the SlowTwitch.com comments were more than likely multisporters. That flipped on a light bulb for me making me aware of yet another major variable that would downgrade someone’s FTP if the guidelines in my original post were followed – time in the saddle.

 

The less time you ride in a week, on average, the lower your FTP is likely to be. I suspect that if we compared the FTPs of roadies and tris we’d find that for comparable levels of competition within their sports that the roadies would have higher FTPs. I don’t know that for a fact but I’ve seen something like this happen four times in the last five years with clients and myself. I’ve had three clients who went from multisport racing to bike-only racing for various reasons. In each case the athlete's FTP increased significantly. The biggest change was for a 50-something male with a couple of decades as a very competitive triathlete who went from 240 watts at FTP as a triathlete to 280 watts as a road cyclist – a 17% increase in less than three months. The same sort of thing, only not quite so great a change, happened to me when I had to stop running five years ago due to a knee that didn’t like it any more after nearly 50 years of running. My FTP increased about 20 watts over the course of a season.

 

So why do I think this happened for each of these triathletes? More time in the saddle. And, along with that, more hard workouts in a week on the bike.

 

I would say, based on what I’ve seen in such athletes, that the less time you ride in a week the lower your FTP is likely to be. Obviously, if you only ride once a week, no matter what you do the remainder of the days in the week (don’t forget the specificity principle of training) you will have very little improvement in cycling fitness. If you gradually built from one to seven days a week you could expect a significant change in FTP. Why? More specific cycling-related stress. Stress produces adaptation (ala Hans Selye). Greater stress means more adaptation. More adaptation means more fitness in general including a higher FTP. (There is specific training you can do to improve FTP which I will get to at a later time.)

 

Most competitive age-group triathletes ride 3 to 5 times in a week getting perhaps 6 to 12 hours of saddle time. Serious road cyclists typically ride 6 or 7 times a week with perhaps 12 to 20 hours of butt-on-saddle time. More bike-specific stress. Higher FTP.

 

So my very rough guess (no science here – strictly opinion) is that if you are a typical triathlete you can subtract in the neighborhood of 10 to 20% from the FTP you estimated from my previous post and probably come closer to a number which is appropriate for you given all of the other variables. The more you ride the less you'd subtract. If you ride a lot, however, like more than 15 hours a week as many serious Ironman triathletes do, your FTP will be on par with most comparable road cyclists.

 

I hope no one takes this to mean that I believe triathletes are poor cyclists. This is not intended to be an indictment of triathlon in any way. It’s merely an observation of a key difference between triathletes and road cyclists when it comes to FTP - an observation which needs to be considered when estimating what your FTP could be with more focused training.

On the whole I think we can figure that a triathlete’s FTP is likely to be lower than that of a road cyclist with everything else being equal – weight, age, gender, body composition, altitude and experience. To be on par they would have to train the same amount and in the same way.

Good luck to everyone doing Ironman Canada next weekend - especially TrainingBible Coaching athletes!

Comments

[Ted]

Joe, I have also observed lower FTP on the TT bike than on the road bike (by 10-15 watts).
The more aggressive the aero position, the more likely the watts are to be lower.

[Ken_sharlin]

I completely agree with Coach Friel in this case. The only thing I would add is that no one has mentioned who would use this calculation in the first place. The calculation is only useful for the cyclist who has just purchased a power meter and has not yet had an opportunity to go out and peform a 30 minute time trial effort to determine their true lactate threshold based on their average power output. Perhaps another scenario might be to compare the estimate with the actual to ask whether the cyclist is undertraining or whether (if a large difference exists) the power meter needs to be re-calibrated.

[Mahting]

Hey Joe, I was a little taken aback by the fact that you could estimate such a thing as FTP because I thought it was more "Scientific". fter reading last weeks post about estimating FTP I went ahead and did it. I will make a few comments prior to saying if it worked or not. I train with power, have a very experienced coach, race as a CAT 2 and am a road rider not a multisporter. I have a very accurate read on my FTP. The estimation was almost spot on if I would train specificly for it, however training for crits chages that a little but I was impressed.

[Joe Friel]

Ted, Yes a very good observation. The more aero you become the more power you sacrifice. It can be a very good trade off for TT and tri however.

[Pat]

Can FTP be improved? Using your estimation, and testing with my power meter, I seem to be about 30W short of where I should be... can I expect to make up that 30W, or more, in one year of training?

[Flemish cyclist]

Hi, calculated 262 W, measured 260 W. Wow !

[Joe Friel]

Pat--It certainly can as I mentioned with examples in my last post on this topic. can you do it in one year? Too many "it depends" to be able to answer that. The last one I mentioned is a pretty basic "it depends" --how many times you ride in a week chronically.

[Ethan]

Joe- As a cyclist in my 2nd year of riding I'm not sure if my body can handle lot's of training hours week to week. I've been averaging about 10 hours/wk (with some variation depending on the period that I'm in). Two quick questions: Since more saddle time=higher FTP, should we aim for the highest number of yearly hours that we can handle without it having a negative impact on form? And as we become more experienced (from years and years of riding) is a cyclist's body typically able to handle a higher load of workout stress?

[Joe Friel]

Ethan--Thanks for your comment. Being a bit conservative is always wise regardless of one's experience in the sport. It's just that the absolute volume tends to rise as more experience (and resistance to injury, illness, etc) improves. Ride at a volume always that allows for performance improvement. The key to this is adequate recovery weekly, monthly and annually. All of this is explained in my Cyclist's (and Triathlete's and Mountain Biker's) Training Bible.

[Sean]

"So why do I think this happened for each of these triathletes? More time in the saddle."

So does this not say:

More Training = Higher FTP

And does this not go against your basic premise about quality (volume) of training versus quantity?

BTW you are missing the beautiful 110 degree riding weather here in Scottsdale.

[Joe Friel]

Sean--More time in the saddle also means more opportunities to do quality training.

[Lisa]

Hi Joe - I'm beginning power training with my indoor cycling class, and have just finished a 30 minute test with them - gave them the chart with percentages to fill in. Here's the problem I encounter when adapting power testing to indoor cycling classes: all of the tests are premised on either an outside ride or an indoor ride in the saddle (efficiency decreases so much out of the saddle). Some of my people do not even ride outdoors, so I want the training to be useful to them as well - they like being out of the saddle - a lot. How do I maintain the accuracy of power zones as measures of intensity and give them the time out of the saddle that they want? I've considered doing separate testing to measure zones out of the saddle - does that make any sense?

[Joe Friel]

Lisa--Thanks for your comment. Either in or out of saddle is ok for FTP testing. I really don't care which my athletes do. I know they won't stay out of the saddle for 30 minutes straight or in for that matter. They'll undoubtedly do both when riding in a workout anyway. Some are actually slightly more economical when standing. And the economy difference between seated and standing is really insignificant. It's roughly 20-25% for everyone. A much greater concern is the temp of the room they are riding in and the wind moving over their bodies. That's a huge variable.

[Angela]

I agree with more time on the saddle will improve FTP. I tested this last year, for three base periods riding 18-20 hours per week. At the end, I surprised myself seeing a big 25% increase in my power from my last FTP test done. Believe me, I was very happy and re-tested the following week to make sure the power tap is not broken or reading incorrectly. pretty cool...