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Post deleted by Kraig Willett
Re: TT Pacing Strategy Analysis [Kraig Willett] [ In reply to ]
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Sounds like the results you have found is what I have always been inclined to do- vary the power a bit. I always beat myself up for it, and now I know that maybe I wasn't so off-target.

It has been years since I have used the SRM crank. Now, I wish I had access to it. But I do remember when I had used one. Quite a fascinating piece of machinery, for certain. Your article makes me think of acquiring one once again.

Very informative article. I may have to sell a few things to get an SRM crank to try out what your srticle says.
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Re: TT Pacing Strategy Analysis [Kraig Willett] [ In reply to ]
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Very interesting work. I've always used a variable effort in my riding, and I can actually have better TT times on slightly hilly courses compared to flat as a pancake courses. I think it is partly because, as you said, the human body is not a robot. My heartrate can recover very quickly on a few seconds of downhill rest, so I don't have to worry about it going "too high" (whatever that really means is another question altogether) on a short hill, as long as my muscles don't get that "freshly baked" feeling. Also, I'm a relatively heavy (read this as meaning I coast downhill well!), naturally fast-twitch kind of athlete, and I've only spent a few years trying to convert over to slow-twitch endeavors....so I don't do as well at the constant-state sub-anaerobic efforts as I do on the blast and coast efforts. This is also why I won a lot of races back in the 80's...if I was still around at the sprint, I never lost. Another fellow, a slow-twitch relatively fast grinder, and I, would sometimes break away on a steep hill. Then I'd follow him on most of the flats. He'd follow me up and down the hills...it worked well, and we successfully used that technique together on many races. I'm gradually losing that blasting ability, but my flatter riding is faster...I guess I'm slowly becoming a slow-twitcher after all! I'll still use the variable effort riding technique though...it feels so familiar, plus, it just may be faster, too! Thanks for the link to your work.



Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)
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Re: TT Pacing Strategy Analysis [Kraig Willett] [ In reply to ]
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Hey Kraig.
I believe it's pretty much spot-on, the average is higher when you increase the lower, not the higher speed. Makes physical sense to me
This is the same pacing one should use against headwinds ( harder effort ) and tailwinds ("rest") - I believe the results would be pretty much the same.

Now on a personal note for all TT'ers out there. I lost my big TT of the year because I lined up for the start and I was afraid - of my race, of the competitors, afraid of the course. I had a great ride, my avg heart rate was the highest I've ever got for a TT of that distance ( 191 for 45 mins ) and I "gave my all", but I didn't have that "eye of the tiger" thing - and I knew when I finished I didn't "had it". It's not (just) about your pacing, your power, your aeroness. It's about the pain, and enjoying that pain so you push harder to "get" even more pain. Just didn't happen.
Ok, turning this into a rant, yada yada. Better luck next year.

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Re: TT Pacing Strategy Analysis [Kraig Willett] [ In reply to ]
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Interesting analysis. Did you consider the physiological effects of going anaerobic in a TT? Presumably if this race was on a flat course you would do it at your Lactate Threshold effort. To increase power 5% on the hills you would have to increase your output above your LT. This approach would have you constantly fluctuating to above LT and below LT efforts.

I have heard that in longer races, like Ironman races, that every minute you spend above LT on the bike costs you much more than a minute on the run due to increased fatigue.

What about in a shorter race, like a 45 minute TT? How bad is it to go above LT?

(My approach has always been to make myself stay below or at my calculated LT for the first 25%, ride as fast and smooth as I can for the middle 50%, ignoring calculated LT during this period, then consciously riding well above my LT for the last 25%. However, this approach is based on my own experience, not science, so I am curious what others do and what science says.)
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Re: TT Pacing Strategy Analysis [MarcK] [ In reply to ]
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In Reply To:
Interesting analysis. Did you consider the physiological effects of going anaerobic in a TT? Presumably if this race was on a flat course you would do it at your Lactate Threshold effort. To increase power 5% on the hills you would have to increase your output above your LT. This approach would have you constantly fluctuating to above LT and below LT efforts.

I have heard that in longer races, like Ironman races, that every minute you spend above LT on the bike costs you much more than a minute on the run due to increased fatigue.

What about in a shorter race, like a 45 minute TT? How bad is it to go above LT?

(My approach has always been to make myself stay below or at my calculated LT for the first 25%, ride as fast and smooth as I can for the middle 50%, ignoring calculated LT during this period, then consciously riding well above my LT for the last 25%. However, this approach is based on my own experience, not science, so I am curious what others do and what science says.)
I think 'science' questions whether a true LT exists at all, and I think it's also been demonstrated that blood lactate levels vs. power output (and HR) is highly variable from day to day.
Last edited by: JustCurious: Jul 2, 03 9:11
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Re: TT Pacing Strategy Analysis [Kraig Willett] [ In reply to ]
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Now this topic is right up my alley! I did the Pro/1/2 TT last thursday and your analysis of the course is very interesting.

I did pretty well, finishing 23rd and only a second behind Chris Horner of Saturn. I don't have a power meter or spedometer on my TT bike as I prefer to focus on my HR. My HR data was a little high but I think the 96 degree temps. had something to do with that. I will post my HR graph later on tonight so you guys can look at it.

I find the Fitchburg course tough because of that first hill. It is VERY difficult to keep you HR down on that first hill. As much as you try to keep your HR down, your power output is going to go higher on that hill. There is a fine balance between getting over that hill in a descent time and overcooking yourself for the rest of the ride.
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Re: TT Pacing Strategy Analysis [Kraig Willett] [ In reply to ]
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I did this analysis of some potential TT pacing strategies for the recent Fitchburg Stage Race TT for a completely different audience, but I figured you all might be interested in the results. The model I used was simplified (no inertial considerations - yes, I am working on that ;-) ), but the first order results have corresponded well with the literature available on the topic.

The results didn't really surprise me that much (go harder on the hills and recover on the descents), but what is really limiting any further progress on the approach is how I model the power profile and, more importantly, how this relates to _individuals_.

Anyway, have a look if you get the chance, and as always, I value your feedback.

http://www.biketechreview.com/...pacing/Fitchburg.htm


Couldn't this be viewed as sort of analogous to the theory behind a typical interval workout...

By alternating work intervals with recovery you're able to spend more total time at higher intensity, higher power output levels and do a greater total amount of work in a given time period than you could with an all out, but constant level of effort.
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Post deleted by Kraig Willett [ In reply to ]
Re: TT Pacing Strategy Analysis [Kraig Willett] [ In reply to ]
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If you have the condition that the average power is going to remain constant, then it is completely obvious that the power will be most advantageously expended going up hill. When you are going up a hill, your speed is low and nearly all of your energy goes into pulling you up the hill against gravity rather than pushing air out of the way. Going downhill, any energy you put into the pedals will just allow you to get a slight increase in speed against very stiff wind resistance. The greater percentage power variation you allow, the more the time savings will be.

Unfortunately, the real world is not so simple. We pay for our power spikes afterward. Unless you can model the penalty we pay for high intensity climbing, your model won't help much.

I think everyone puts more effort out when climbing. If the hill is some reasonable length, I try to push over the top and then back off on the downside. I am no model of efficiency though. Put a power meter on Lance and you will get your answers fast enough.
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Post deleted by Kraig Willett [ In reply to ]
Re: TT Pacing Strategy Analysis [ajfranke] [ In reply to ]
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VERY well put, that unless we can model the penalty for our power spikes, the results don't mean that much.

This penalty amount is what I think is one of the differences between individual cyclists. If you have a group of cyclists that can all put out a steady 250 watts for an hour and have very similar flat TT results, why does one person have such a much better hilly TT result? I'm not talking about a climb...usually the lighter fellow will win that one. But, on a hilly TT the fellow that can exceed 250 watts at times, and then recover the quickest, will be the one that stands out of that crowd. Different people have different physiologies that result in varying ability to recover from these peaks of power output.

I happen to be one of the riders that can maintain a higher average speed on hilly courses than flat ones. Or, probably more accurately stated, I lose less average speed on hilly TT courses compared to my buddies. I'm a decent flat TT'er, but I'm an excellent hilly TT'er.

That's a big problem in trying to model this equation, Kraig. The physiological differences between riders that in one case seem to be very similar (flat course TT'ing), but are very different when put in another situation (hilly course TT'ing). My guess is that you'd have to know what type of physiology an individual has, and then have a variable assigned to that type of physiology, in order to get a real good guess on that individual's estimated TT. Let's don't even get into the differences in aerodynamics where one guy coasts downhill faster and has a little better flat section time. Yikes! So many variables...it's quite an endeavor to undertake.

Keep up the work! These are interesting ideas you keep bringing up for us to ruminate upon!



Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)
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Re: TT Pacing Strategy Analysis [Kraig Willett] [ In reply to ]
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No Kraig, I am afraid I can't eyeball the course and tell you how many seconds you could save. I would have thought it would be more than 4 seconds actually, but a 5% difference is not very much. I suspect you would have a bigger savings if you had the model rider powering well over the hill and then throttling back.

I have no clue how you would model how the power spikes suck the zip out of your legs. I only know that once I blow, I am toast for about a week. I need to nurse my power very carefully. Take me and someone half my age who does say an Olympic length triathlon in about the same time. If you have us do the race every day for a week, he would be crushing me everytime after the second or third day.
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