Determining FTP using a Kurt Kinetic?

This is just a thought that I will throw out.

A couple years ago I was in the exact same spot. A guy with a lot of desire and seeing a lot of guys and gals reporting progress by training in zones based on power output.

I had the KK trainer and was using a HRM, but I like you wanted to refine my training.

I checked around and fortunately in a metro area like Atlanta there were a number of sources to test my FT. There were coaches, gyms, bike shops, exercise physiologist and rental opportunities that advertised testing Functional Threshold. I went to one of the bike shops and they put me through my first test on a stationary bike equipped with a calibrated power meter.

Like you stated I then could take that data from the test and use it on the KK trainer with speed and the power curve chart. It got me a little closer to what I wanted until I could afford a PM.

I am not sure if you live in a metro area or a place that has such resources to get tested, but maybe that is something to consider if you do.

Thanks Felt Rider

Thats certainly something I could do, and I did investigate doing a battery of tests earlier this year, but my concern is simply how transferable the data is to another machine? My understanding is that different machines using different technologies/protocols will give different absolute numbers so they arent directly comparible?

I've looked at renting a PT wheel or similar, but with several bikes I ride frequently it seems a limiting solution? I'd love the Speedplay pedal mounted system to become available and prove effective so I could use it on any bike!

Is there some kind of extended interval or time trial effort I could do to estimate the speeds/zones to use simply on this machine?

I will let someone else help you with a refined answer.

I do know that using a trainer for a FT test will be difficult if that is the place you want to perform the test. It will take a lot of focus and a lot of cooling for a 20 minute all out effort.

I can say this about the KK power curve that it appears to line up with what my power meter reading for mph and watts. Just as the chart states for example at 17 mph on the trainer is right around 180 watts.

I agree with Felt that it's going to be difficult. There are two main problems. One is that it's really hard to put out your full FTP on the KK. I used to have one and I could not get within 20w of my road FTP even after weeks of using it. It's something to do with the machine's ability to carry momentum through the pedal stroke. (I now have a Computrainer and I can get very close to my road FTP with it, as measured by the same power meter.)

The second problem is that your estimate of power output is bound to be inaccurate. Even though the KK is pretty good, the power/speed relationship of any trainer depends on things like what tire you use, how much press-on force there is, tire temp and fluid temp. The KK does not drift a whole lot -- maybe 20 watts from cold to warm -- but it does drift, and the press-on force will change your power output as well. On my computrainer the amount of press-on force I use can change the readings by 50+ watts at the same speed, so it really does make a big difference.

So bottom line is you could give it a try, but I wouldn't put much faith in the results.

I have the KK Road Machine as well (great trainer btw).

If you go on this link: Stationary Indoor Bike Trainer - Kinetic by Kurt you will find the KK power meter. It costs $184, but some shops sell it for $150.
Depending on how bad you want to train with power, this is a nice option. The only catch is that the power will only read correctly on the trainer and not on the road. However, all the other functions (speed/cadence/heart rate/temp/climb), will work outdoors. Also, as sated before, the trainer does not give a 100% accurate #'s, but it's good enough.

I have it and it works great for me. I train with the power and zones all winter long, and use it as a regular computer on the road. I am upgrading to a PowerTap this year though.

Good luck,
-Greg

OK - seems like some flaws in my plan then...

My plan was to try and minimise the variables as much as possible by keeping 1 bike on the KK over winter, with a dedicated trainer tyre at a constant pressure left on the roller. With a warm up to raise the fluid temp I was hopeful the error levels might be relatively minor, although it will be in an unheated garage so ambient temperatures will vary widely.

I can see the issues with doing a test on the KK as well, but with those in mind, what test should I be using to get some form of approx readings?

Well the good news even though your plan may not pan out exactly like you wanted and the numbers not quite as exact the chart for physiological adaptation, though defined with hard lines, is actually more gray. Meaning there is not a definitive line for adaptation between lets say L3 and L4 as if to say, "at this very precise number these physiological changes occur." The physiological changes occur somewhere near those zones and probably vary per individual rather than precise lines.

If you can get to or at least near the sweet spot by RPE it is better than nothing. You can still manually enter data into a program like WKO by kind of guessing at IF, enter the time trained and the speed from your 705 and you can sort of track your efforts. Perhaps from that data you will start to get a picture and a history of progression or detraining.

So if you get your training in or near those zones with RPE or other methods for the time being you will do okay. When and if you get a PM you can then get it all more precise.

I think you will do okay. Sounds like you want to be structured and you are pursuing that avenue so I am guessing you will do well despite lacking a PM.

thanks for the encouagement

I've done a field test with the CTS Time Crunched Cyclist and used numbers from 5 & 10km efforts to calculate zones using the Friel calculations, and they come out fairly close and consistent. I've been doing intervals on the road using these numbers and they 'feel' very accurate in that a few bpm higher and I can feel the change in lactate/effort in my legs.

I suspect I have the HR numbers dialed in fairly well right now on the road, so maybe just doing some intervals on the KK at these zones and taking note of the corresponding speeds on the machine and basing some zones around those. As you say, there are no hard and fast numbers for the perfect development, so theres obviously a lot of guesswork at best!

Time for more reading...

I think you should be fine using the KK. I have one and have compared the calculated power output vs a powertap and it seems to be within about 10% or so which is good enough for the training you are looking at doing. Even if the error was higher the main feature you're looking for is consistency and I found that to to be reasonable.

To find your FTP just test the same way you would outdoors i.e. do a 20 min test as hard as you can divide that by .95 and call that your FTP. It's irrelevant if the trainer FTP is a little lower than outdoor FTP since you're going to be training indoors. The bottom line: After you determine your FTP, if you do a 2x20 set of intervals @ 100% and they feel too easy, just raise the speed (power) until they are hard but doable.

One more thing - you should have a large fan pointed at you for cooling.

gregf83 said:

I think you should be fine using the KK. I have one and have compared the calculated power output vs a powertap and it seems to be within about 10% or so which is good enough for the training you are looking at doing. Even if the error was higher the main feature you're looking for is consistency and I found that to to be reasonable.

To find your FTP just test the same way you would outdoors i.e. do a 20 min test as hard as you can divide that by .95 and call that your FTP. It's irrelevant if the trainer FTP is a little lower than outdoor FTP since you're going to be training indoors. The bottom line: After you determine your FTP, if you do a 2x20 set of intervals @ 100% and they feel too easy, just raise the speed (power) until they are hard but doable.

One more thing - you should have a large fan pointed at you for cooling.

Exactly, except I think you multipy by 0.95 instead of divide.

I also have KK trainer with the wired power thingie, and it works great for power training. It doesn't matter if it's your real FTP or not, as long as it's repeatable. And like the previous poster says, if you find the intervals too easy just raise the intensity.

There are also threads in here somewhere where people are discussing / speculating why they can't generate the same power indoors as they can outdoors. For them, this holds even for measurements on their powertap.

this matches my thinking - actual comparison to other power figures is irrelevant as long as its constant. With your 20min test suggestion I should be able to set some clear zones initially.

Sounds like the first step in my structured winter plan 😎

lanierb said:

I agree with Felt that it's going to be difficult. There are two main problems. One is that it's really hard to put out your full FTP on the KK. I used to have one and I could not get within 20w of my road FTP even after weeks of using it. It's something to do with the machine's ability to carry momentum through the pedal stroke. (I now have a Computrainer and I can get very close to my road FTP with it, as measured by the same power meter.)

Because of my work, commute and life schedule I have returned to a steady diet of indoor training.

My first week back on the KK trainer not only am I about 15 to 20w down from my road FT my effort is not smooth. The trainer (by RPE) feels smooth and the speed on the PT cpu may read a near constant speed, but my watts would bounce 50 or so every other pedal stroke. I could not hold a near constant wattage.

After about 3 weeks I see the data in WKO chart is becoming more steady looking or at least if I set a line at the top of L4 and the bottom of L3 my data is at least within that range. The first week it was a mess and was all over the place. :o

It will be nice when I can get to the point I can consistently hold the effort in one zone. 🙂

I know this sounds sick, but I am really starting to like the feel of the trainer again. I am not sure that I will match my outdoor efforts because I am betting as I improve indoors the outdoor effort will equally improve and I will be always chasing that outdoor effort. However it pans out I see improvement already starting to slightly rise in WKO, the trainer is starting to feel painfully delightful and riding on the road is just feelinng that much sweeter.

Lots and lots of work to do though. I am way behind all of you guys and gals.