Intensity factor for a TT

The Flash!

Hi all!

If I didn't reach a 1.0 in intensity factor during my last TT, does that mean I could have gone a little harder?

The Flash!

whoawhoa

It could also mean you have overestimated your FTP. How long was the tt?

The Flash!

It was just over 25 minutes....

I've done to previous 20 minute tests and they are within 5 watts of each other. My IF was .95 for the TT and I was about 6 watts below my FTP. I'm thinking I left a little too much in reserve....

The Flash

djconnel

Another possibility is you weren't as strong on the day of the TT versus the days of the test, due to fatigue, illness, different environmental conditions, bike position differences, etc, so you didn't actually leave anything in reserve.

The Flash!

I have been feeling a little more tired than usual, but at the end of my 20min test, I was really out of breath. In the TT, I kept my cadence down to save some energy for the final headwind run. I was out of breath by the end, but not during the previous 7 miles. Should I have stepped it up a bit more in the beginning?

The Flash!

frenchyge

6 watts is 5% of your FTP???

In any case, I would expect a 25min TT to be paced at slightly above FTP, rather than below. Are you using the 20MMP x .95 to estimate your FTP?

djconnel

Well, I'm not an expert in time trials, by any means! But my feeling is it's really important to not get badly bogged down in headwind sections, so while you could have invested more power up front, given the conditions, better to have held a little too much back going into the final headwind, then to have held back too little (best to hold back just the right amount, of course...)

The Flash!

Sorry...forgot about that calculation....I was actually above my FTP then....my 20min wattage is 252, which makes my FTP 239. In CP, I have 252 entered in my FTP wattage section, so I'm thinking that is the wrong number in there. Need to go back and recalculate that IF then.....

The Flash

The Flash!

It did seem to work out for me, especially when I was passing all of those riders at the end! I probably could have gone faster with that tailwind in the beginning, but I would have been hurting in that headwind. This course traditionally has a headwind to start and that's where I blew up in my first TT there. Did much better on the second one when I learned to hold a better pace to start. Now I've just got to learn to tighten up the pacing some more and really find out how far I can go before I blow up!

the Flash

jbvcoaching

Was the testing done on your TT bike/position? Similar terrain to what you TT'd on?

The Flash!

Similar terrain, just a closed off 7-mile loop with no traffic. However, I did the test on my road bike. Do you think I need to repeat the test with my TT bike? After adjusting CP for the .95 of my 20 minute time, my IF is now 1.04.

With that in mind, I am wondering if I produce more power on the TT bike? I do like the position a lot better as I have relatively short femurs and the TT position does make me much more comfortable.

The Flash!

Thorman

If you're like most people you probably produce less power in your TT position. My FTP is ~10% lower in my TT position. I setup a second athlete in Cycling Peaks for my TT FTP so that I get the correct values for IF and TSS.

jbvcoaching

Well, it sounds like you can repeatedly do 252W for 20 minutes on your road bike in training, but you only did 239 or so for 25 minutes in a TT with a number pinned on (i.e. - motivated). So just from this one test I'd say that you, like many people, are producing slightly less power in a TT position.

Had you not tested or trained on the TT bike?

The Flash!

239 is from when I take my 252w *.95 to get my FTP. I actually kept 248w during the TT. I am thinking that I am the opposite. When I did the 252w on my road bike, I had a much higher heart rate at the end. When I just did the 248w during the TT, I still felt like I had more to give. Given my wide shoulders and upper body, the road bike is always a much harder ride due to wind drag. I "feel" much faster/powerful on the TT bike...

I train on the TT bike pretty regularly, but I have not done a 20 min test on it yet. Now that I am in the full swing of TT season, I'll be on the Plasma much more often.

The Flash