Hey Vo2over, What is the 20-2-20 protocol? I think all FTP protocols are estimates to look for your lactate threshold, olba, or mlss. Using that number to create workouts specific to your goals i.e. >vo2max, >threshold etc.

From what I've read here the best way is to do a 40K TT. Problem is not all of us have that option on a regular basis and doing that on a trainer would be mentally brutal. I have used a 20min/5min test to gauge my fitness level and as a base for training, not a true FTP but it will get you in the ballpark.

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Just a question for you guys on your mental side.

Do you find doing a 20 min all out test easier or harder than 1 hour test mentally?

Personally for me, I find the 20 min all out more difficult mentally than 60 min, because I am actually going harder (physically). The higher continuous wattage just "hurts" more. For the same reason, I find a 5K harder than a 10K run.

On a trainer I feel that 60 min is harder, outside I feel that 20 min is harder. It's all mental, which I'm sure I am :)

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If your 3min test increased, but your 20min stayed the same, that would indicate a higher anaerobic contribution ergo a lower FTP. Odds are, depending on your training, if your 3min test increased, then your 20min will too, and the slope will stay the same.

The concept of threshold is reasonably simple, right? It refers to this idea that every athlete has a point at which working just a little bit harder means having to stop a lot sooner. Now, Andy Coggan has foisted this idea of FTP, which is really very reasonable. We know that one hour power is closely correlated to lactate threshold because of the work of Ed Coyle, so you go out and test for an hour and you get a nice number that is correlated with a physiological marker that we know is important with respect to performance. It is also nice because a 40kTT takes about an hour if you are well trained. If we looked at other things like MLSS or OBLA or whatever, we'd also find that they are highly correlated to one hour power.

The problem is that most cyclists (and triathletes in particular) don't want to go out for an hour and slay themselves. So we have a predicament on our hands. The Critical Power model presents a nice alternative because it has been validated many times, it is highly correlated with performance, and it is "direct" in the same way an hour long FTP test is "direct". In other words, we aren't looking at some indirect physiological marker like lactate, and trying to divine a "threshold" phenomena where one may or may not really exist.

We know a lot of interesting physiological things happen within the muscle itself as you cross Critical Power, even by just a couple of watts. For instance, you see rapid and dramatic changes in the levels of particularly important things (pCR, Pi, pH). We also know that crossing CP by just a couple of watts results in rapid fatigue and cessation of exercise. It is my suspicion / impression that the "threshold intensity" we feel is actually best correlated with Critical Power. For these reasons, I think the model is really very useful and this is what I use for all of my athletes, amateur and pro alike.

Using the model, what we are really tying to do is figure out where the power / duration curve "flattens out" to the point that you could sit on that power for a "long time". Your observation that raising the short term power (i.e. the 3 minute test) without raising the long term power (i.e. the 20 minute test) results in a lower CP is exactly correct. It now would appear that power is fading quicker from 3 min to 20 min, and thus will be lower at an hour. This is why it is important to test both numbers any time you use the model to figure out what your "threshold" is. If you are training appropriately for triathlon, both should be improving over time.

The take home message is this: There is no magical "threshold intensity". Whether you want to refer to FTP, or you want to calculate CP, you are basically talking about the same thing. It isn't that one is "real" and one is an "estimate". I'm not suggesting you use one to estimate the other. You are simply trying to figure out a power that you can hold for a "long time" and using that as the basis of your training program. Which one you use is basically irrelevant. I'd advise just picking one approach and sticking with it.

Hope that helped!

Phil
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Dr. Philip Skiba
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no, FTP is FTP. How much power can you produce in one hour. Metrics are power in watts, and time in minutes.

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Thanks Dr. Skiba!

For the OP, I have been using this model and have found it to be very useful as a coach and athlete. I use a 5 min and 20 min test personally.

As Dr. Skiba pointed out, it gets you 'the same' number as other protocals. But now I don't have to recovery my athletes during that week. It's also something that I can get them to do physically and mentally on a frequent basis to rebaseline if necessary.

In short: I'm a fan.

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Technically...yes. But, unless you have some ungodly amount of anaerobic capacity, you'll also find that the result of that calculation is typically within a handful (i.e. less than 5W) of the slope value (Critical Power).

Besides, tracking of FTP is typically done as a measure of your long term, sustainable power...i.e. the power you can maintain aerobically IS the definition of FTP (power average over 60 minutes is a proxy for determining that), which basically describes the Critical Power, or slope, of the Monod caculation.

Also, if your short term power rises, but your longer term power doesn't...then, by definition, your aerobically sustainable power will have been lowered. So yes, your FTP is actually lower.

Power at 1 hour is MUCH more about your aerobically sustainable rate than your anaerobic capacity.

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1) It ain't "Skiba's FTP test" - the critical power paradigm has been around for several decades, and I'm the one who originally suggested using it to estimate functional threshold power based based on a 3 and a 20 min effort (see this post from 2002 where I brought the critical power concept to people's attention: http://groups.google.com/...g/dbaf2ed122589566).

2) The reason that you don't want to add in the intercept is because the relationship between work and time isn't really linear (as assumed by the calculation). Ignoring the intercept gives you a slightly lower value, which helps correct for this non-linearity.

3) If your 3 min power increases and your 20 min power does not, then yes, you would calculate a reduction in critical power. That is, in fact, what would happen if the increase in 3 min power were due to an increase in anaerobic work capacity (which isn't quite the same as anaerobic capacity, at least as how I use the terms). OTOH, if the increase in 3 min power were due to an increase in fatigue resistance due to enhanced aerobic energy production, then your 20 min power should go up as well, and hence the slope of the line would increase.

So you invented power. Awesome. You and Al Gore have gotta get together.

No, but I did invent snarkiness, so I wish you'd stop imitating me as well. ;-)

Thanks for the replies,

Since I haven't done a 3min all out test and a seperate 20min test as per Skiba's book, the best data I have for a fast comparison is from by latest test using the protocol in Coggan's book. See chart below for CP and FTP data. I deduct that the difference between the measures is pretty small.

I have done the 20-2-20 test (best average of 20min hard, 2min easy 20min hard) and the "30min max test" suggested by Gordo (95% of 30min best effort) and found that results for me are within 5 watts between these and Coggan's protocol.

Gotta try the 60min test and the 3min/20min CP curve test :o)

I have a seperate question that maybe Skiba and Coggan would be nice enough to give me feedback on:

How hard to go on different VO2max intervals?

The upper limit typically used for VO2 work of 120% of FTP seems to hurt just right for longer 2-5min VO2 intervals.

For 30s/30s intervals (say 4x(5x30/30)) 120% feels "light", but maybe I am just fooled.

I have seen 100% of 5min max power prescribed by some for 30s/30s.

Skiba's book has 106-120% FTP (as Coggan) OR 95-105 VO2max.

I have yet to do the Montreal Track Test to see how that compares to 5min max effort so my only VO2max estimate is the 5min test.

For me: 120%FTP=337w, 5min=354w, 105%5min=372w.

What power should I target for 30/30s, 2min and 5min VO2max intervals?

For 30/30s, if I go as hard as I can backup for the 4x(5x30/30) I am around 410w; had to check that out :o)

Along the same lines, what is your opinion on 30/30s versus longer VO2max intervals as the best tool to raise VO2max?

Taking 95% of your maximal 20 min power is actually Hunter Allen's approach, not mine. It will almost always put you in the right ballpark, but I figure that if you're going to set aside the time to do a formal test, you might as well do something a bit more accurate.



Basically as hard as you can and still complete the intended number of intervals w/o fatiguing excessively.

(IOW, I wouldn't obsess over the precise intensity, as the frequency and motivation with which you perform such workouts will have much more to do with how much progress you make.)

Thanks so much Coggan and sorry for using CP/Skiba/Coggan etc. so freely :o)

So what do you personally prefer for VO2max and FTP testing (sorry if I should know)?

Regarding intensity with respect to VO2max intervals: There is substantial variability between athletes with respect to what fraction of VO2max CP / "threshold" may occur at. Thus, I think your best bet is deciding on how you want to determine what surrogate you want to use for your power at VO2max and then target that ballpark.

Based on my experience with triathletes, I find short (less than 5 min for sure) and sweet (as close to power at VO2max as the athlete can get) are optimal both in terms of response, and ease / speed of recovery.

However, don't lose the forest for the trees. As Andy intimated, consistency is really what is key. The optimal balance is highly individualized. Just pay attention to how you feel, what is going on in your key workouts, and you will find your own "best recipe".

Phil
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Dr. Philip Skiba
Scientific Training for Endurance Athletes now available on Amazon!

how do you feel about friel's 30min indoor tt for estimating ftp? (not sure if its truly friels but he does mention it)

I thought I would add this link as a good reference:

http://home.trainingpeaks.com/...threshold-power.aspx

So exactly where did the 20-2-20 come from? I want to be a CP/FTP historian :o)

Question about taking a % of 20 min power: Last year I did a flat TT, all-out, at XXX watts, which was fairly typical when I had good fitness & on a flat course. A week later I did a TT, all-out, with a sustained climb at XXX +9 watts (true data point). And if I jumped on my road bike and went all-out on a 20-min climb, I'd be + ~20 watts. So which do I use as a basis?

I think it was Rich Strauss of Endurance Nation.

It's always the biggest number :-)

Chris, I don't think either of those two climbing situations are unusual by any means. Many people fall into that category.

Given that flat terrain will likely make up the greatest % of your overall riding it would make sense to choose the first. Either way, I'm pretty sure the protocol specifically states that flat terrain is most desirable.

Thanks, Chris

Ok, so here's my wrinkle to this thread. We know that these principles apply to all activities, including running and swimming, and so it makes sense to design training for those sports in a similar way. However, it is much more stressful to run a 3 min and 20 min time trial than it is to do them on a bike. How do you (and I'm being specific here, I really mean Philbert and the rest of you) sort out your training/racing schedules to regularly get these data points?

>>Given that flat terrain will likely make up the greatest % of your overall riding

Not so much, really. I actually prefer road racing; TTing makes up less than 25% of my races (just happens to be what I'm more proficient at). With regard to training, the only time I spend on flats is for TT workouts (perhaps 4/15 hours per week), otherwise I'm in the hills/mountains.

Agree those numbers are pretty typical, just curious which ones to use. E.g, if I go off TT bike #s then I could be coming up short for road racing. Alternatively, if I use road bike #s, they might be too much for TTing?