2x20 and ft questions...confused, please help

BlueJersey

Power meter is a training tool, not something that will make your faster in a race. Most people dump their power meter on a race day. Any training you do with a power meter is to induce adaptation == making you faster for longer duration. They don't necessarily simiulate a race condition. They could if training on a hill climb or simiulating the power and duration required to launch a massive attack. And sprinting. You are too obsessed with the 1 hour FT test. Very unlikely you will be completing a 40km TT since that distant is too long for beginners. Also, in a race, it is more important for you to be able to generate 150% above your threshold power to match surges and attack. In a race, you don't TT for an hour. It is better for you to work on your max power output for your 20 minutes duration than to focus on your average power on a hour "TT effort."

whoawhoa

I would guess it is both. As you get more used to using a pm and let power drift more on upgrades/downgrades it will probably seem easier. If you try to ride hilly terrain at constant power perceived exertion will probably be up.

Off topic, but where do you live/race Chris? I think I've raced against you before, and I'm surprised your ft isn't higher. Do pts need to be calibrated or something?

cshong88

I live just north of Baltimore...I just started cycling seriously though back in August...and only did one TT, JFX in October (I think it was October). Did we race? If you live around here, we should do some riding together or something.

BTW, when doing 2x20s on the trainer and determining FT from them...is FT the avg. power of the 2 intervals or is it the avg. power plus the 5 min. rest interval in between?

-Chris

whoawhoa

No, I live in Georgia. Weird coincidence.

RapDaddyo

Ignore the rest interval. Your FT would approximate your AP of the high-power intervals only.

BTW, if your primary interest in knowing your FT stems from wanting to do your intervals at the target power levels to induce the desired adaptations (e.g., Andy C's schema), there is an alternative approach, one that I use for all of my intervals. The approach is simple. For every duration from ~3-30 mins, find your max NP (by trial and error). In CyclingPeaks, this is easy because you can set up a power/duration chart to give you this for all durations. I then ride all of my intervals at 90% of this MP number. So, if my MP for 10 mins is x watts, I will ride my 10 min intervals at .9x. I then just let the terrain of my courses dictate my interval durations. If I have a 4.5 mile 25 min climb, I climb it at 90% of my 25min MP. It turns out that these power levels also fall into Andy C's schema, with the shorter durations coming in at the upper end of Andy's range and the longer durations coming in at the lower end of the range.

frenchyge

The answer to that is kinda two parts: 1) I ride my trainer almost exclusively in the winter, and outdoors almost exclusively the rest of the year, so I don't have a great need to translate between the 2 modes. If I had to make one FT adjustment in the fall, and a second in the spring, then that wouldn't bother me a lot. 2) Part one, above, is not really necessary because after a short adaptation period (1-2 weeks) I find that I'm able to generate just as much power on the trainer as I did on the road, and vice versa. I did a trainer ride last summer when I first got my PT and I couldn't hold 10 minutes at what I could do for an hour on the road, but after riding the trainer a few times I was able to train at a level consistent with my summertime outdoor rides.


Personally, I don't worry about cadence too much and don't even have the cadence hooked up on my trainer bike. For me, RPE does seem a little higher at higher cadences, though, so it might be something to watch if your cadence differs a lot between trainer and outdoor riding.


Whoawhoa hit the nail in his response to this, and I think it'll become apparent for you after a couple weeks with the PM. Outdoors, the power varies hugely between a slight incline and a slight decline. If I were to try a threshold interval on the rolling terrain here, I would aggressively charge up each hill, and then mash a really big gear down the other side. My power on the climbs would probably be 375-425w going uphill and 200-250w going downhill, but not by choice. That'd just be the best I could do in each case.

If you were trying to maintain target power on the climbs, then I'm not surprised that your interval power ended up too low because it's very difficult to maintain a high power on the downhills.

cshong88

I find that doing this approach though leads to a higher RPE...if you are working on the uphills harder and then working hard on the downhills too (which sometimes is even harder for me), things get tiring a lot more quickly than on the trainer...is this how you feel too or this just an adjustment thing?

frenchyge

I can't say, since I don't do intervals outside and inside during the same week. That's just the approach that I'd have to take to do a 20-min interval outside. Keep in mind that the NP calculation will naturally weight the high-power segments more, so that helps. For example, a 5 min climb at 350w followed by a 3 min descent at 200w yields an AP of 294, but an NP of 316w. It's possible that riding a little above target on the climbs and then pushing hard on the descents will get your NP where you want it.

cshong88

Well, now I'm curious about Coggan's writing about 2x20s being FT...

He says that what you can routinely produce during 2x20s is a good estimation of FT and in a particular thread here he mentioend that routinely meant day in and day out.

However, I hear that many coaches assign 2x20s at the lower end of the threshold range. Even Coggan says that 2x20s should be done just under race intensity (or at least that's what his Training with power thing says).

My question is...if 2x20s are meant to be done at the lower end of the threshold range or just under race intensity...how can 2x20s be an accurate estimation of FT? Wouldn't it be lower?

And what is the RPE of these 2x20s? After doing the 2x20s on the trainer indoors (213, 214W), then only being able to do one 20' outside the next day (191W), I tried a 2x20 yesterday again on the trainer...but only could do 2x15 at 211W each. So....are 2x20s when done day in and day out like Coggan says, mean to be done at an RPE that makes it a struggle to finish or just really hard? Basically, if I can do the 2x20s at a certain intensity every day...is that my FT or is that lower than my FT?

whoawhoa

I don't know why a coach would assign 2x20s at much lower than 100% of threshold power. Where, exactly did you see that he wrote this?




I would not put too much stock in your second effort at the workout, since you had completed the same workout the day before and also may have not paced very well given the terrain. How much recovery did you have after those two days before your 2x15?

Also, 2x20's every day are not realistic. I would use whatever your best effort at 2x20s is for your threshold, so long as you didn't go absolutely into the red zone to finish the workout. That should be plenty close enough. The usefulness of setting ft is to calculate training zones, normalized power, tss, etc, not to micromanage every interval session to the watt. So if ft is off 2-3%, that's not a big deal.

cshong88

But I'm confused because Coggan whose research etc. i am trying to base my training off of said that 2x20 power generated routinelyis FT, not your personal best for a one time 2x20. That 2x20 was done when I was very fresh, but it was also a very very hard workout...and again, routinely means day in and day out (according to him). And with school work and all, it is not very often that I can feel as fresh as i did going into that 2x20 i did earlier.

I would think 2x20s could be done at least every other day. Should I really keep FT at 213 (my avg power from the 2x20s) or decrease by a little and by how much?

And I am right then to say that 2x20s should be done at 100% FT? When Coggan says day in and day out 2x20s, does he mean for these to be at 100% FT? (well...i guess they should be at 100% threshold because he does say that 2x20 power generated routinely is FT). But on the other hand, he says in his trainign with power manual that 2x20s should be done just below race intensity...which is less than FT...what's the deal with this?

RapDaddyo

Based on three pieces of data, I think your FT is lower than 213w. First, you said that it felt like a near-MP effort at the end of the interval. Second, you said your power declined over the course of the interval. Third, you had difficulty doing an NP of 213w on your road course. That scenario screams out that 213w is too high (at least right now). FWIW, I do all of my intervals >2 mins at 90% of my MP for that duration. Why not 100%? Because the recovery is longer and the benefit is no greater. So, why should I pay a price (in terms of more valuable training time riding at a recovery pace and thus gaining no training benefit) for no incremental gain in adaptation? Exactly. That's why I ride at 90%. Following my approach, if the 213w felt like a near-maximal effort at that duration, I would do my weekly 20s at ~192w. If the 213w was not a maximal effort, but close to maximal, I might use 200w for my weekly 20s. You'll know soon enough if you need to increase your power -- it will seem too easy at 192w (or 200w or whatever you decide to use).

frenchyge

I'm pretty sure that means 'during a typical 2x20 workout' rather than 'every single day'. Most people seem to do their 2x20's once or twice a week, while fairly well rested.

Remember that the goal of the workout is to improve power at LT, rather than to determine FT. From that perspective, lower L4 is perfectly fine.

Do a few more workouts with your PM and get a better feel for what power you can produce during a hard, 1 hr workout. 2x20s aren't supposed to be an accurate assessment of FT, they're a rough indication based on a possible difference between training motivation and intensity, versus teeth-gritting TT pace.

Intervals should be done at approximately the highest power that allows one to complete *the whole set.* The end of your second 20-min rep should hurt pretty bad, being as how you'll be at the end of a 45-min (total) hard effort.

frenchyge

To be clear, and so we're not giving conflicting advice, 213w was not his maximal 20-min power. 213w was the average work power over two 20-min efforts with a 5-min rest in between.

If you want to follow Rapdaddyo's method, then go ride a single, 20-min effort where you are totally dead at the end, and then multiply the NP for that ride by 90% to set the power level for your typical 2x20 workouts. That way, you'll be nearly dead by the end of the *second* rep rather than the first.