Power geek question from quadrant analysis
I'm playing a little bit before the real OS starts and trying to learn some things about my cycling strengths and weaknesses.
This led me today to do a ride where I did some 3 minute high-power VO2-type intervals (among a few other things). I was a little too aggressive about the power target I wanted to hit and managed to get it on the odd ones, but not the even ones, which came in about 5% low.
Looking at this on quadrant analysis, what I found was that virtually all the variation between the intervals was in the cadence. The pedal force was about the same for all of them, but the low power ones had a a lower cadence (velocity), i.e., the cluster of points moved to the left on the chart from the high to lower power intervals.
OK, now I know this... but what do I make of it?
Does it give me something diagnostic to work on or focus on? Does it tell me something about the gearing I should be using if I'm tired on a VO2 interval?
(Normally my cadence is >90 for 2/3 of my ride or more, but for the high power stuff, it's in the 80s. Ave cadences were all in the 80s for these intervals.)
Still trying to understand what all I can make of this tool!
William
Comments
William, was this an outside ride? If so it's probably hard to really do fine tune adjustments on the fly. I haven't used quadrant analysis for this topic but I think I sit on the trainer sometimes and over think the issue.
My perspective, which I think is really the same as yours is what decisions I make as I start to tire out. As I'm grinding out an interval and getting really tired I start to think of how to maintain power; do I change gears and either grind or spin faster, or do I just put my nose to the grindstone and maintain cadence.
I used to think that as I got tired, I'd drop to harder gear, drop the cadence but hope for more force and power. Lately I've switched thoughts on this and really try to keep cadence steady. I should pull up the quadrant analysis, but my guess is that I would see the same results as you, drop cadence and lose power.
P
What is your feeling about doing the short intervals (say 5-6 minutes or less) at low vs. high cadence? (or vs. whatever your normal cadence is?)
You read in some places about developing "strength" by doing low cadence (and I know force on the pedal isn't exactly my strong point), but it's easy to show that the actual force on the pedal isn't a huge amount compared to doing squats or whatever. On the other hand, folks like Carmichael seem to advocate very high cadence for the short intervals...but I can't tell if there's a scientific/physiological reason for that, or if he's just playing the "I did it for Lance, and don't you want to be like Lance" game.
The topic of Cadence in VO2 max intervals is something that concerned me a lot last season, but without a proper EN outseason under my belt the amount of V02max work, i.e. mostly 30/30s, that were in my race prep blocks was pretty minimal.
During the somewhat limited 30/30 sessions that I did do however, I found it much easier to maintain 'epic' power during the 30s on by dropping the cadence and really grinding a gear. This felt like cheating to me, I was able to maintain a higher power without sucking wind and wanting to collapse over the front of my bars for longer this way, but I had to really kind of slap myself and remember that there is no reward for seeing how high of an NP I can rack up for an itnerval in WKO, the whole reason I'm out there is to induce the maximum targeted dose as part of the dose/response model.
This goes back to what P said, as a PM athlete and based upon my own experience I know that super low cadence high power efforts are not sustainable for longer durations, however in the specific case of the 30/30s I found them *more* sustainable but recognized that I was basically doing the opposite of what the workout intended. By slowing my cadence I was essentially turning what should have been an anerobic sucking wind effort designed to increase aerobic capacity into a much more aerobic excercise in 'weight lifting'. Perhaps I was increasing leg strength / pedal force this way, but our FTP workouts are designed to increase leg strength, not our VO2 max blocks.
Bringing this all back around to the death of the 30/30s in the 2011 OS in favor of the 2.5/2.5's, I for one am looking forward to this change. I'm sure it won't be pleasant, but I know I can't hold my 'cadence hack' for 2.5 wheras I could for 30, increasing the liklihood that I'll do the workout as it was actually intended.
This is great stuff from everybody. I've struggled with cadence sometimes when trying to do longer TH intervals. I found with me, that I when I am fatigued, I can grind out the rest of the interval and hold my power with a lower cadence. When I analyze my workout, my latter intervals almost always have lower cadences but the same or higher power and I'm comfortable doing that. I have a hard time keeping my cadence up to maintain power, and have actually seen some of my indoor files where the cadence has been held, but for some reason power dropped? Obviously something to do with my rollers and probably heat.
@Trevor: funny you mention how your vo2 seemed to be aerobic. I think I did all my 30's intervals wrong. Since the intervals are so short, I didn't even bother looking at the PM and just dropped the gears and pedaled as hard as I could until my watch beeped. I figured that the watts would be the majority vo2 wattage for me with some anerobic capacity and some TH watts mixed in as well and didn't even worry about my PM numbers... I was breathing pretty hard. Now, did I do the workout right, I don't know, but my kj were always high for those workouts and my graphs always spiked for them too. I don't think it hurt me. But, changing the 30's to 2.5 min will probably solve this problem and make the work interval more focused. For power work in zone 5 and 6 does cadence matter? I can't believe that even though some cadences can be too low, once the work accumulates, you will start to suck wind at some time? You are still working at a vo2 wattage, leg speed alone can't determine ventilation can it? Just curious because I don't know.
I too have noticed that my indoor cadence tends to be lower than my outdoor cadence. I tend to think this has to do with the resistance response of my trainer, relative to the gearing I'm used to using and how it just "feels". I'm definitely planning on trying to keep the trainer cadence up with my outside cadence this year if I can.
Re VO2s, you're definitely going to suck wind at XXX watts after 2+ minutes there no matter what cadence. However, I think there is still a "purpose" to doing them at higher or lower cadences - I just wish I knew what the differences were in the muscle-fitness response to the differences.
I don't know what the deal is with cadence. I tend to like Dr. Skiba and what he has to say for the most part because he references all his statements. I believe that he said that there is no significant difference in cadence and power from 65 to about 110 rpms I believe. So I don't hold too much stock in my cadence numbers as long as I'm not too extreme either way, self selected cadence seems to work just fine, to the point I removed my cadence sensor so I'd have less on my bike, and less to worry about metric wise with analyzing workouts. When something comes out research wise that states something drastic, I'll worry about it more.
Yes, it is! If I could understand all their jargon!
To the topic at hand......
There is a section in the "Training and Racing with a Power Meter" about cadence and power. Some of the more interesting points: Most people have a self selected cadence. When pedaling at a typical self selected cadence, functional threshold power appears to occur at the power at which significant fast twitch fiber recruitment first begins. Also, you can divide pedaling force and cadence into the 4 quadrants and analyze them in WKO 3.0. In order to excel at different types of pedaling, you need to match the quadrant in training. For example, if you ride a lot of sprints, you need to practice being in the high force/high velocity bucket.
I think Patrick's point is key. Use a power meter and try to hold certain paces for long periods of time (i.e. FT or 90% of FT), you realize pretty quickly that your self selected cadence works pretty well over the long haul.
All within reason of course. No big difference between 88 and 86...
@Mike: I completely understand your point. For me, I consider the training zones all a continuum and for 30 seconds, I figure that my wattage is crossing my vo2 for the majority of the time. Now I'm not standing and mashing for the interval, but I get going hard to get up to wattage, sit back and try to hold. At that intensity (for me) I don't look down so that I'm staying on form and can't really see the numbers at that pace anyway for that short amount of time. So I'm not all out sprinting, but hammering hard and basically using RPE at that point. When I get to the new OS plans, I'm sure I'll be paying more attention!