tag:blogger.com,1999:blog-7494097266323039749.post4931771700422322950..comments2016-01-14T07:47:50.763-08:00Comments on Training and Racing With a Power Meter Journal: Prediction of muscle fiber type from powermeter data, part 3Hunterhttp://www.blogger.com/profile/10476979058435683579noreply@blogger.comBlogger14125tag:blogger.com,1999:blog-7494097266323039749.post-12619156556960785412014-05-06T23:04:54.994-07:002014-05-06T23:04:54.994-07:00I think that ergometer is the best way to fitness ...I think that ergometer is the best way to fitness your body and muscles. It might not be the bad idea and I really wish that an ergometer is in your fitness tracker. <br /><br /><a href="http://ergometer.org" rel="nofollow">Ergometer Test</a>Anonymoushttps://www.blogger.com/profile/06803174374677999408noreply@blogger.comtag:blogger.com,1999:blog-7494097266323039749.post-19092011333867376802011-06-06T08:51:49.753-07:002011-06-06T08:51:49.753-07:00I went through the numbers reported in figure 4, a...I went through the numbers reported in figure 4, and it seems to be the other way around: 18% advantage for seating over standing.<br /><br />I obtain seated: 713 W at CPV 2.05 m/s and AEPF 346 N.<br />Standing: 586 W at CPV 1.36 m/s and AEPF 431 N.<br /><br />This can also be easily seen graphically because the mid point for the X intercept for the standing line is found below the seated line. <br /><br />I'm sure Dr. Coggan can reconcile this better with the other points he made in the blog. I will only venture that the main reason why people stand is not for power but for added force (which is shown by the part of the standing line above the seating line). <br /><br />From an endurance point it may seem counterintuitive, but there could be a benefit in standing too: if I'm standing and pedaling at the most efficient speed for standing, which is lower than seating, I'm using less power than if I were seated and pedaling at the most efficient pedaling speed for seating. In turn I will be taxed at a lower metabolic rate.Giovanni Cirianihttps://www.blogger.com/profile/14699613390034881999noreply@blogger.comtag:blogger.com,1999:blog-7494097266323039749.post-48229518541533945272011-04-11T09:10:22.300-07:002011-04-11T09:10:22.300-07:00I was going to comment on the latest post but you ...I was going to comment on the latest post but you seem to have disabled that feature :) Anyways, I just wanted to mention that I was using a Quarq with 1s recording via Joule for my data collection. I have also not noticed the spikes that you mentioned in the blog post above this. And to give a little more credibility to the 1s recording I have been averaging ~60% TypeI and 40% TypeII using this method. I recently got a track bike and was experimenting with what the maximum cadence I could achieve when I remembered that max = 2x optimal. Using this method and adjusting for crank length I also got 60% I and 40% II (238RPM w/ 165's I think). Anyways I thought it was interesting/exciting that both methods gave me the same result so I thought I would share.Jasonhttps://www.blogger.com/profile/10786349413799076515noreply@blogger.comtag:blogger.com,1999:blog-7494097266323039749.post-82720004191511258102011-01-26T10:51:06.197-08:002011-01-26T10:51:06.197-08:00The *theory* is that by increasing your cadence, y...The *theory* is that by increasing your cadence, you reduce recruitment of fast-twitch motor units (not increase recruitment of slow-twitch motor units). This theory, however, ignores the fact that both the force *and* the velocity of the (intended) muscle contraction play a role in determining the level of central motor drive at which a given motor unit is recruited. Thus, in point-of-fact what the research actually shows is that the cadence at which you pedal has little influence on the overall pattern of motor unit use. To the extent that it does, however, those with a lot of slow-twitch fibers would want to pedal more slowly, not more rapidly, as this would mean that these primarily-recruited motor units are working closer to their optimal speed of contraction. Again, this is in fact what has been found in at least one study, i.e., self-selected cadence was lower in those with a higher percentage of slow-twitch muscle fibers.Andrew R. Coggan, Ph.D.https://www.blogger.com/profile/07152375621226680227noreply@blogger.comtag:blogger.com,1999:blog-7494097266323039749.post-61680927309319973792011-01-26T10:00:11.794-08:002011-01-26T10:00:11.794-08:00How does that fit with the ideology that if you in...How does that fit with the ideology that if you increase your cadence, you increase recruitment of ST fibers because you are reducing the force requirements? With that thinking she would want to use a high cadence to utilize her predominantly ST fibers. Should we focus more on our 'optimal' cadence instead?Jasonhttps://www.blogger.com/profile/10786349413799076515noreply@blogger.comtag:blogger.com,1999:blog-7494097266323039749.post-60332145483544822382011-01-26T09:23:03.313-08:002011-01-26T09:23:03.313-08:00I can think of a number of situations in which the...I can think of a number of situations in which the enhanced self-knowledge gained via such testing could potentially be useful. As you suggest, selection of gear/cadence during TTs would be one of them. <br /><br />Indeed, this was exactly the case when my wife raced the 2007 Missouri state TT on her pursuit bike. As an inveterate trackie, the notion of using a gear bigger than something in the low 90" range was abhorent to her. Based on the results of F-V testing, though, I knew that she was clearly skewed toward the slow-twitch end of the spectrum. Based on her functional threshold power, CdA, etc., I also knew that she could go well under the hour. I then calculated that to keep her cadence close to her optimum (for submaximal power production), she would have to use a huge gear, at least by trackie standards. She was skeptical, of course, but agreed to use a 50x13, or 104" (I'd actually pushed for something even bigger, but we compromised). She went on to smash the course record with a 56:52, >8 min faster than the 2nd-place woman and faster than all but six men. However, more important (to me, anyway) was the fact that she said she never really felt the urge to shift up or down during race, except during the last couple of kilometers where the sight of the finish line and a slight tailwind had her wishing for an even bigger gear. Without the understanding achieved (in part) via the F-V testing, though, she would have used a much smaller gear, and would have likely produced less power and gone slower as a result.Andrew R. Coggan, Ph.D.https://www.blogger.com/profile/07152375621226680227noreply@blogger.comtag:blogger.com,1999:blog-7494097266323039749.post-10729811473266616212011-01-25T15:18:31.613-08:002011-01-25T15:18:31.613-08:00Can this information be used for any other purpose...Can this information be used for any other purpose? For example, can the 'optimal' cadence help determine a target cadence for time trials?Jasonhttps://www.blogger.com/profile/10786349413799076515noreply@blogger.comtag:blogger.com,1999:blog-7494097266323039749.post-22620180549021553532011-01-24T13:57:57.061-08:002011-01-24T13:57:57.061-08:00Jason,
Fatigue would be expected to result in a s...Jason,<br /><br />Fatigue would be expected to result in a slowing of the maximal velocity of muscle shortening, so the fact that your predicted % type I area* was greater the day after riding up some steep ascents may not be all that surprising. Looking at the pic you provided, though, I wonder if part of the issue simply isn't variablity in the data - that is, when using an SRM set to record at a high frequency, the power-velocity (or force-velocity) relationship should be a lot tighter than what you obtained. Maybe you're not using an SRM, though?<br /><br />*The original study correlated optimal cadence with % fiber type area, so technically the results should be viewed as such. As it turns out, though, there generally isn't enough difference between human type I and type II fibers in terms of their cross-sectional area for this to have much of an impact on things. <br /><br />For example, in my hands at least the gastrocnemius muscle is, on average, ~50% type I and ~50% type II, with the latter fibers being ~20% larger than the former (in young individuals, anyway). Even taking this difference in fiber size into account, though, the % type I area is still 50/(50*1 + 50*1.2) x 100% = 45.4%.<br /><br />Of course, training can impact the contractile properties of whole muscle (and limbs) via mechanisms other than changes in fiber size, such that the velocity at which maximal power is produced can change slightly over time. In this regard, the *predicted* type I fiber area percentage can be viewed as a way of "pinning a single number on things", even if biopsy-determined fiber type hasn't *necessarily* changed.<br /><br />(Being a pragmatist at heart, one of my long-standing arguments has been that if someone walks like a slow-twitcher and talks like a slow-twitcher, they are a slow-twitcher, regardless of what any tiny snippet of their muscle might suggest.) <br /><br />AndyAndrew R. Coggan, Ph.D.https://www.blogger.com/profile/07152375621226680227noreply@blogger.comtag:blogger.com,1999:blog-7494097266323039749.post-61693076838650596792011-01-24T13:38:56.711-08:002011-01-24T13:38:56.711-08:00Rayomond: Thanks for the complimentary comments re...Rayomond: Thanks for the complimentary comments re. our book. <br /><br />As for your question about the Polar, it sounds to me as if the device is at least periodically "locking onto" some resonant frequency than that of the chain. This is a known issue with the Polar device, at least/especially when used indoors. I have not used one myself to have any really good suggestions, but some people report that they are able to get good (i.e., reproducible) power readings indoors by 1) carefully positioning the receiver on the chainstay, and/or 2) taking steps to eliminate other sources of vibration (e.g., placing the trainer on some sort of rubber mat). If you hunt around the internet a bit I'm sure you will be able to find more detailed information.<br /><br />AndyAndrew R. Coggan, Ph.D.https://www.blogger.com/profile/07152375621226680227noreply@blogger.comtag:blogger.com,1999:blog-7494097266323039749.post-5879743885626135012011-01-22T17:44:59.606-08:002011-01-22T17:44:59.606-08:00I guess the answer to my question is that above ~5...I guess the answer to my question is that above ~50% VO2max we recruit both type I and type II so the greater amount of type II you have for a given power you will recruit more 'inefficient' type II fibers. <br /><br />Here are my results from yesterday (52% I) and today (64% I). The interesting thing is today's was after a few steep climbs and my results showed more type I. I wonder if this is a quick/easy method to determine aerobic & anaerobic fatigue based on max power and subsequent %fiber recruitment. <br /><br />http://i248.photobucket.com/albums/gg179/msuguy512/Fiber.jpg<br /><br />My final question is, is this measuring % fiber type, or % surface area. If I do a bunch of anaerobic intervals, won't my optimal velocity increase quite a bit, even though my fiber type won't have changed significantly?Jasonhttps://www.blogger.com/profile/10786349413799076515noreply@blogger.comtag:blogger.com,1999:blog-7494097266323039749.post-83657959276035104322011-01-20T14:11:41.312-08:002011-01-20T14:11:41.312-08:00I was only half kidding, but I will try it again t...I was only half kidding, but I will try it again tomorrow seated. The other thing I was thinking is if the muscles can process 2-3times the amount of oxygen that we are limited to giving them, then wouldn't it be more beneficial for a cyclist to have a small amount of type I, and a large amount of type II. lets say you have 2 units of type I and 1 unit of type II compared to 1 unit of type I and 2 units of type II, both the 1 and 2 units of type one should be able to produce the same amount of power since we are only limited by the amount of oxygen we can deliver and not muscle mass. Then the guy with the 2 units of type II would have more 'reserve' to attack and be stronger during shorter efforts. Since this doesn't seem to be the case I am wondering what I am missing in my equation.Jasonhttps://www.blogger.com/profile/10786349413799076515noreply@blogger.comtag:blogger.com,1999:blog-7494097266323039749.post-11066905433642576272011-01-20T10:18:34.281-08:002011-01-20T10:18:34.281-08:00Dear Dr. Andrew, recently bought ur book 2nd editi...Dear Dr. Andrew, recently bought ur book 2nd edition & was delighted to read through the chapters (though still on chp 6); it instantenously made sense of of all the different training levels(from Recovery to Neuromuscular Power) U have made it so simple & easier to understand.I have been reading about these from different books /blogs over yrs bt was always confused on how much time to spend on each and when to incorp what & write a training plan with clarity of backgroud knowelege. Thank you for efforts in presenting knowledge in this manner; now i know what to actually do with the power meter. I live in Pakistan and over here there is absouletly no concept / assistance for scietific training so i am on my own figuring out from different books & online literature. <br />I had invested a small fortune (from our Currency stds) into Polar's Power meter CS600 WIND & have been confused on the stochastic power output flashing on the screen (this subj. though is nicely covered in chp 5 your book as to why it happens). I now have following q/s :<br />Q- While training indoors on the Trainer (Cycleops Fluid 2) & doing VO2Max drills of 3~4Mins should the POWER readings vary if all other variables are KEPT constant (i.e. Gear and candence)? My results vary btw 180Watts to 240Watts which is significant margin. Is this generic and i should only focus on the uploaded data from the workouts or is there something wrong with my power meter???? <br />Thanks in advance and do keep on sharing knowledge online. <br />Regards<br />RayomandUnknownhttps://www.blogger.com/profile/15229081087359057316noreply@blogger.comtag:blogger.com,1999:blog-7494097266323039749.post-63417636645697294312011-01-19T12:57:52.657-08:002011-01-19T12:57:52.657-08:00Jason,
110%, eh? Well, a prediction is only a pre...Jason,<br /><br />110%, eh? Well, a prediction is only a prediction...but I have to wonder whether you're able to accelerate the pedals fast enough. You need to be able to reach your optimal cadence w/in a handful of seconds, or else you'll "fall off the line" due to fatigue.<br /><br />AndyAndrew R. Coggan, Ph.D.https://www.blogger.com/profile/07152375621226680227noreply@blogger.comtag:blogger.com,1999:blog-7494097266323039749.post-76410586006072331912011-01-18T11:41:19.082-08:002011-01-18T11:41:19.082-08:00Seated? Hmmm, I guess I am 110% ST then :)Seated? Hmmm, I guess I am 110% ST then :)Jasonhttps://www.blogger.com/profile/10786349413799076515noreply@blogger.com