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Thread: 2x20 Vs 4x8

  1. #21
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    Default Re: 2x20 Vs 4x8

    Quote Originally Posted by MarkC View Post

    In vague terms, unlike the FRC math, "tolerance" its how quickly you can recover from higher wattage efforts.


    -Mark
    This is one of the parts I find interesting. The research and numbers just apply a logical explanation to what I've always observed (long before I had a PM). If your w-prime or FRC are larger than average, it makes sense that it takes longer to fill back up. My experience (with what seems to be atypical physiology in this regard) bears this out. I see other riders able to do consistent 5-6 minute hill repeats (Boston people all know Blue Hill) with just the roll back down the hill for recovery. I can't do it if I go full gas on the way up. Not even close. From a training goals perspective, anything that I can do to shorten the recharge time is going to be hugely beneficial.

    The other more interesting piece is the time dependency of w-prime. I can't tap into the entire capacity in less than 4 or 5 minutes. In fact, my 2 minute best power isn't much higher than my 5 minute. There is more in play here than just w-prime for sure. GC shows you the percentage of w-prime used up and available on a graph (I am guessing that some of the newer computers can show this on the handlebars), so you can see how close you get to 100% depletion at various durations and effort levels.

    I also have a crackpot theory that w-prime/FRC is greater when you stand up, because upper body muscle mass is also involved. Usually I can get about 5% more watts out of a steep climb where I do some standing than I can on a flat pursuit effort of the same 5 minute duration. This year I've been trying harder to close that gap as I feel seated power at high rpm is more relevant to what I want to achieve. I'm too heavy to climb well anyway!
    Last edited by jellysidedown; 1 Week Ago at 07:32 AM. Reason: too means too
     

  2. #22
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    Default Re: 2x20 Vs 4x8

    If your 2 and 5 min power are not that much different (and you can't recover quickly enough from 5-6 min. repeats)- you are likely trying to do the 5 minutes efforts at too high of a power level.
     

  3. #23
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    Default Re: 2x20 Vs 4x8

    Quote Originally Posted by boots2000 View Post
    If your 2 and 5 min power are not that much different (and you can't recover quickly enough from 5-6 min. repeats)- you are likely trying to do the 5 minutes efforts at too high of a power level.
    Actually referring to all out testing, max power for duration. Just don't have a big 1-2 minute ability. Two minutes full gas is maybe 15% higher than my 5 minute best.

    Doing something like 4x8 with 3-4m recovery I'm much lower. Typically I like to do those as the first phase of a kitchen sink ride rather than a standalone session. So I don't go nuts, maybe 10-20% above CP for starters and then see how it goes. You can always dig for more on the third or fourth one.
     

  4. #24
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    Default Re: 2x20 Vs 4x8

    A few data points to stoke the fire. Last week 4x8min w 2 minutes recovery (terrain was rolling so...). Threshold HR is low 160s and FTP around 230
    W-HR
    243-161
    236-160
    232-161
    228-159

    Two days later 2x15minutes with 5 minute recovery
    207-153
    224-160

    Yesterday towards the end of a 1h 5m climb that averaged 199w and 149bpm, and finishes at 2200m

    Last 30 minutes at 219w 159bpm
    Last 20 minutes at 227w 162bpm
    Last 10 minutes at 229w 164bpm

    Scratching my head as to why the 4x8 no's aren't bigger
     

  5. #25
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    Default Re: 2x20 Vs 4x8

    Disclaimer: No judgement in what follows - hoping to help. Assuming you are interested in building fitness over time and the focus on FTP is not necessarily for an hour effort but as a useful metric for setting training zones.

    Quick reaction to your date is you may not be working hard enough for the intervals.

    Lots of reasons for why that could be.

    1) FTP estimate is wrong
    2) Not targeting the right effort level for the work (high or low)
    3) Mental focus
    4) It takes practice and experience to do intervals well
    5) ???

    Question: How are you power testing to define the FTP? The classic 20 minute test needs to be done with the right protocol which includes a priming effort of a few minutes prior to the 20min work. Not just taking your best 20 minute from a ride. Also want to look at the steady state work not the burst at the start and the surge at the end. I kinda look at 20 minute tests taking out the first and last 2 minutes. Another power test is warm-up, 8 minutes max, ten minute recovery, 20 min constant power effort at 90-95% estimated FTP. The 20 min effort is typically 80% FTP. When I do this test am typically 290-310w for the 8 min and 240-245 for the 20 min.

    It takes several runs to get comfortable with testing to get consistent (useful) results. Most riders don't test near often enough. Because it stinks and it hurts. It may be a good idea to test a few times perhaps using both protocols to nail your FTP and then set some target powers for intervals.

    If you think the current FTP estimate is correct then two suggestions:

    1) Forget about 8 min intervals. Those are long(ish) for VO2max and tax different systems. Lets try to nail your VO2max effort level and find a workout you can nail before moving deeper. I would try a 5 x 2 min interval set with 3-4 min rest between efforts. 270w target would be 117% of your FTP. A typical target for this type of workout is 115-120% When you can do 5 x 2 min at 115% increase to 2.5 min. Then 3min.

    When 5 x 3 min is solid you can start reducing the recovery time or think about different durations. 4 x 6min is a very useful workout to boost FTP and extremely hard to complete at 115-120% of FTP.

    2) 2 x 15 is a great workout. You should be able to do this at FTP. When I do 2 x 15 the target is actually CP20 x 1.05 (5% over CP20) In my case CP20 is 250 so I'd shoot for 260w. Suggest you stick with your FTP estimate and not worry about CP20 or other targets for now. When you nail a couple 2 x 15s at 235w then bump it up to 240, then 245, etc.

    In terms of fitness over time and building FTP over time, one can go very complex or keep it simple. I've found simple works well during the season. AVO2max workout and a threshold workout once a week is a good foundation. Add in a strong and long ride (group or solo) on the weekend and a race. So a typical week:

    Monday - rest
    Tuesday - VO2max
    Wed - tempo
    Thursday - Threshold (2 x 15, 2 x 20, 1 x 45)
    Friday - Openers
    Saturday - RACE
    Sunday - Long ride

    That will be 500-550 TSS at an IF around 0.8

    Base and Build are different since there is no race day and we have winter so long ride day may be inside.

    Full disclaimer - I'm a guy you don't know on an open forum. I probably don't know much and no guarantees any of the above is insightful, correct or useful.

    -Mark

    Complete aside on power tests: It turns out that a 5 min all out blitz is a decent test in well trained athletes who know how to test. You have to go as hard as possible from the gun. What happens is you start huge and then fade. As long as you dig hard to the end of the interval, the last 90s or so will give you a good approximation of FTP. It hurts like hell but it's fast. Some coaches use this a a sneaky test protocol. Rather than saying: "Let's power test on Thursday" they say "do a 60-90 min ride and somewhere in there give me a 5 min all out effort and don't give up to the end". Athletes don't see that as a power test so the coach gets some data without introducing anxiety.
     

  6. #26
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    Default Re: 2x20 Vs 4x8

    Quote Originally Posted by MarkC View Post
    Another power test is warm-up, 8 minutes max, ten minute recovery, 20 min constant power effort at 90-95% estimated FTP. The 20 min effort is typically 80% FTP.
    Typo in my above post. Should read: The 8 min AP is typically 80% of FTP. For example, a 300w AP in an 8 min test equates to an FTP estimate of 240w.

    In the example, its a good estimate if you follow that up with a 20 min effort at 240w. The 20 min piece should feel pretty good. Robust but not eyeball bulging difficult and your HR shouldn't be soaring.

    etc etc etc
     

  7. #27
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    Default Re: 2x20 Vs 4x8

    Mark,

    Thanks so much for such an in depth response!

    I haven't done a full FTP test since the spring, so it's entirely possible my estimate is suspect. I did bring it down about 10W and 5 BPM from where it had been, but it could be off more.

    There's also been a lot of dieseling and not very much intensity since then, so I may have lost my sense of what hard really is as well.

    I do have a few years of structured efforts on the bike behind me, (preparing for and racing TTs) and a decade of running track workouts and races, so I do have a pretty good sense of what hard work feels like.

    The feeling I have while doing the shorter repeats is I just can't generate enough power. I started feeling "normal" in the second of the 2x15s, and the last 30 minutes of the climb earlier this week, so may-be it just takes time to get my engine going.

    Regardless, I think you are right about the 2x20s and that's were I'll put my focus for the next few weeks.

    Thanks again - much appreciated.

    Larry
     

  8. #28
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    Default Re: 2x20 Vs 4x8

    Quote Originally Posted by zank View Post
    I've been really interested in FRC and how it relates to cyclocross. Mine has been coming up in WKO4 as I've been doing some more 30 sec, 1 min, and 2 min efforts. No where near 32 kJ, but over 20 in WKO4. Cusick said their algorithm considers over 23 kJ as "High" and desirable for a cross racer.

    I was going to post this in the WKO4 user group on facebook, but does anybody know if the FRC calculation is based on set FTP? In other words, if my FTP is set low, does that inflate FRC? Or is it based on the power duration curve?

    I wish the wattage group was less confrontational and combative. I'm too intimidated to post there :)
    Just saw this. Yeah, I avoid the wattage group. I want this to be fun...

    FRC definitely relate to what you say your FTP is. The standard response to getting a high number is that you must have your FTP set too low. But it's the job of the software to pull out your power profile from all of your data and make the calculations for you. That is what the "profile" that shows on your summary page in GC does. It recalculates each week, but I'm not sure how far back in time it goes to make each calc.

    Skiba has noted on the GC discussions that anything over 25kJ is suspect. Simply not seen. So I wonder if my FTP is set too low, but I've been dumping my data into GC for years and the calculations keep coming back at over 30kJ. It bases your CP/FTP calc on efforts over 20 minutes near as I can tell. I do plenty of 20 minute efforts. I try to do an HoP about once a month but it's probably less than that. Still enough to get a good calc of my CP, which currently is calcing to 260ish. So the FRC number comes from how far above that you can go for x duration. If I do 375 for 5 minutes then that is 300 seconds at 115w over CP, so 34.5kJ. Again, the knee-jerk response is always that my CP must be higher than that, but I've never been able to back that up with a long duration effort. I've also been doing this for 30+ years, long before the days of the power meter, and nearly all my race wins and good results were with big efforts in the last few minutes, such as races that ended on a climb that takes a few minutes. So whether it's 25kJ or 35kJ, I can be quite certain my FRC is high relative to my other abilities. I brought it up earlier because the time to fully "recharge" is going to be longer if your FRC is bigger. But of course the rate of recharge is what is trainable, and extremely relevant to cyclocross. I think that's much of the point of microbursts, 20/20s and that sort of thing. Cross is almost always above CP when you're on the gas, and then trying to recover.

    I know a lot of people don't use GC, but the second graph demonstrates how it tracks w-prime/FRC usage and recharge. In practice you can hover on the high and low points and see what it give you for actual numbers. Recharge is based on how far below CP you are for how long.

    gc_frc_recharge.png
     

  9. #29
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    Default Re: 2x20 Vs 4x8

    Quote Originally Posted by zank View Post
    I've been really interested in FRC and how it relates to cyclocross. Mine has been coming up in WKO4 as I've been doing some more 30 sec, 1 min, and 2 min efforts. No where near 32 kJ, but over 20 in WKO4. Cusick said their algorithm considers over 23 kJ as "High" and desirable for a cross racer.
    Mike, you got my interest so i went back and pulled this one from NBX cross last year. Not a lot of "recharging" going on after the initial FRC depletion. All those little bumps matter though. You may only get 20 seconds to recover, but that's what you need to train. The other thing to note is that for cross the graph is going to be deceiving, because when you're off the bike running the power meter is reading zero. The software thinks you're recovering/recharging but in reality it's anything but. The biggest recovery segments shown here are probably the long beach run!

    nbx_frc.png
     

  10. #30
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    Default Re: 2x20 Vs 4x8

    Quote Originally Posted by jellysidedown View Post
    Mike, you got my interest so i went back and pulled this one from NBX cross last year. Not a lot of "recharging" going on after the initial FRC depletion. All those little bumps matter though. You may only get 20 seconds to recover, but that's what you need to train. The other thing to note is that for cross the graph is going to be deceiving, because when you're off the bike running the power meter is reading zero. The software thinks you're recovering/recharging but in reality it's anything but. The biggest recovery segments shown here are probably the long beach run!

    nbx_frc.png
    When your saying thats what you need to train, do you just mean replication, like doing 2 x 20's on a "course" or do you mean more or less doing sprints, with short recoveries, like an over-under type workout.

    I have no understanding of FRC, but will do some reading today. Is it available in GC? do you have an resources or guids on how to use GC best? I currently have TP for both my partner and I, previosly had used GC but gave up as I was getting close to the season, and wasnt able to use it as well as I liked. I like TP a bit more because my PMC would include both power rides and HR rides (power+HR on rd/cross, HR on MTB) a feature I couldnt figure out on GC, but Im sure its possible.
    --------------------
    another jaunt
    REBAR

  11. #31
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    Default Re: 2x20 Vs 4x8

    Quote Originally Posted by s_curran View Post
    When your saying thats what you need to train, do you just mean replication, like doing 2 x 20's on a "course" or do you mean more or less doing sprints, with short recoveries, like an over-under type workout.

    I have no understanding of FRC, but will do some reading today. Is it available in GC? do you have an resources or guids on how to use GC best? I currently have TP for both my partner and I, previosly had used GC but gave up as I was getting close to the season, and wasnt able to use it as well as I liked. I like TP a bit more because my PMC would include both power rides and HR rides (power+HR on rd/cross, HR on MTB) a feature I couldnt figure out on GC, but Im sure its possible.
    In GC the FRC equivalent is w-prime (w^1 but I don't think we have superscript in this editor). Make sure you have the latest stable version too. The interface isn't the most intuitive thing to customize, but once you get used to it it's not so bad. To customize the PMC, for example, click on the "more" in the upper left. of the chart. A Chart Settings dialog opens. If you go to the Preset tab and select PMC (Trimp) and Add Current, I think that is what you want, but I'm not sure. I only use Bikescore (Skiba) and Coggan (TSS). Other charts are customized in a similar fashion. The options available in the Chart Settings dialog vary depending on the type of chart.

    I sort of think of FRC as like a booster battery. At CP or below, in theory you can go for a long time. Anything above that and you're tapping into other energy systems that have finite capacity. But by riding below CP your body is capable of replenishing them, to a point. So above CP you are "draining" and below you are "recharging". I am not knowledgeable enough to say whether you can change the size of your reserves through training (although I think you can, by increasing the size of your glycogen stores, if nothing else). I also believe you can become more efficient at the recharge phase. This is where the duration and effort level of the "off" phase of your intervals comes into play. It is kind of the essence of real interval training.

    In the context of this thread, I feel it plays a big part in how well you can perform the various interval durations being discussed. The intensity and duration of the recovery phase being the main factor.

    My feeling is that doing VO2 or any above threshold interval, you are going to be tapping into your FRC. Even in a longer interval (over 8 minutes) if you are making a "surge" at the end to boost your average for the interval, that surge is surely you using up what's left of your FRC. Fine for a one and done TT or effort, but probably not what you want to do in a series of repeats. In most cases it's probably preferable to meter out your effort evenly. Exception to me would be doing the microbursts or 20s/20s stuff that are popular in CX season. These are too short to be looking at your PM and if you let them jump all over the place they probably more closely replicate CX riding.

    That said I'd be curious to see what GC models for your w-prime. You're a bigger guy who throws out a lot of power. I would expect larger people to have larger FRC as it's not tied to weight. It's just a number.
     

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