Just did a 8min TT...sufficient for constructing levels?

SketchySmurf

Hey, I just got through with my first TT.

Maybe I'm trying to fit a square peg in a round hole here, but can I extrapolate the data I gathered from this test and build reliable power levels with it? I know 30 minutes is optimal, but for the sake of argument, 8 min. info is all you have.

RapDaddyo

You can extrapolate your average power with a pretty big error range depending on the course and how you rode it. Was the course flat, rolling, hilly or what? What was the wind and was it consistent or did it switch from headwind to tailwind based on the course headings? How did you ride the TT -- constant power, constant speed, variable power (e.g., increase power uphill and upwind, decrease power downhill and downwind) or what? What do you and your bike weigh? What was the altitude of the course? Assuming you can extrapolate a reasonable average power for the TT effort, you'll have one data point on the power/duration curve and can make very rough predictions of your max power at other durations if your power/duration curve is "typical."

SketchySmurf

It was done indoors so all those environmental concerns should not be applicable.

I understand now that I have one data point—and this is where I get confused—to base my training on for events or circumstances involving that duration. So though it wont be immediately useful for training that lasts for an hour, I can build ranges for efforts lasting around 8 minutes...

rmur17

nah 8 min is WAY too short to construct typical power training levels. The gold std. is an HOUR TT effort. Personally, I don't have 40k's available so I extrapolate from my latest 30min hard TT effort.

8min can have a huge anaerobic contribution - that can really throw things off.

Do at least a 30min and report back

rmur

RapDaddyo

Well, a few people here will probably go ballistic when I say this, but I have studied my training zones and max power at different durations and I think I can derive functional training powers at basically any point on the power/duration curve. FWIW, at the moment I am using ~90% of my max power and this relationship seems to hold pretty well throughout the duration curve. Clearly, my training power is a sliding scale as a function of duration, but that's basically what you get with everybody else's levels/zones anyway. The physiological adaptation benefit is then a function of duration, with the cut-points I care about (levels 4-6 per AC's schema) being ~3 and ~10 minutes respectively. IOW, I would use interval durations <3mins for L6, 3-10mins for L5 and >10mins for L4. I'm not a physiologist and I haven't had Andy's 8-hr physiology lecture (yet), so I'm really just making an observation here that it appears that I can use ~90% of my MP (max power) at any duration and do intervals at that power. QED. BTW, this isn't coaching advice, just input from one cyclist to another.

frenchyge

Yep. For this reason I agree that a single 8min effort is too short to set interval levels from unless you're going to apply a downward fudge factor to try to eliminate the anaerobic contribution.

Possibly the critical power approach (as mentioned in Andy's power training paper) would work with this data.(?)

RapDaddyo

Disagree, old buddy. An 8min max power effort is valid for an 8min interval, which will be (by definition) an L5 (VO2MAX) interval. Granted, it's not ideal and it's not valid for setting interval powers at L4 or L6, but lots of people (including both you and me, if I'm not mistaken) have not done the "ideal" benchmark (40K TT per AC's schema).

SketchySmurf

*distant scream* nooooooooooo!!!

Ok, now thats out of my system...If 8 mins. is too short, what's the point in having them done? Friel recommends CP.2, 1, 6, 30 (did I miss any?)

Eddie Monnier from Velofit says he doesn't routinely test beyond cp30 or prescribe workouts less intense than CP90 because HR is a reasonable proxy for intensity.

Incidentally, can I approximate LT from my 8minute data set?

RapDaddyo

I don't know about LT, but maybe the following data point will be helpful. I've got a pretty good idea what my 8min MP is because I do climbing intervals in that range on a weekly basis. And, while I haven't done a full-out 40K TT for FT (functional threshold), I've got a pretty good idea what it is as well. For me (and only for me), my FT is ~85% of my 8min MP. That's the smallest possible sample size (1), but it's better than nothing.

HammerHead

Just to throw this into the mix, that's what CTS uses to develop their power (and/or heart rate) ranges. Actually two 3 mile TTs, so a little shorter even.

__________________
I'm only truly happy when I'm anaerobic.

frenchyge

It's valid for 1, sure, but why would you do a single, 8-min L5 workout? If you're going to do several 8-min efforts as part of an interval workout, then you won't be able to hold the same power for all of them because your anaerobic capacity will be depleted before the end of the set.

frenchyge

Sounds like he's trying to set the critical power slope/line, which changes things a lot from your original question. I was saying is that a single point at 8-minutes is going to be hard to set anything from, but now you're talking about doing efforts at 4 different points to determine a line, right? That's a different animal altogether.

My understanding is that the shortest efforts are used to determine the anaerobic contribution so that it can be subtracted to set the longer levels (where the anaerobic contribution is less of an effect).

RapDaddyo

First, I'm not suggesting that he does 8-min efforts at his 8-min MP. I specifically suggested that he use 90% of his MP for the 8-min efforts. Further, as I said, these will be (by definition) L5 intervals. And, yes, I think he can do a full set of 8-min L5 intervals at 90% of his 8-min MP. I do it all the time. But, you can't do (with any precision) what he wants to do, which is extrapolate data points all the way out his power/duration curve from one data point of such a short duration.

frenchyge

Ok, that sounds like the fudge factor correction that I mentioned before, so I'm okay with that.