power vs cadence?

acoggan

Despite what, e.g., Chris Carmichael might claim, that isn't necessarily true - read this for the reasons why (and note that since the relationship between AEPF, CPV, and power is a fixed mathematical one, it doesn't matter that I only present data for myself):

http://home.earthlink.net/~acoggan/setraining/

youhaditcoming

Hi,

high cadence can be a bit of a visual effect also, you might say Armstrong's cadence looked higher than the rest of the guys...sure, but more important was the actual gear he was actually moving at those RPM ! that's what made him faster in the end, his physical ability of shifting to harder gear without lowering his cadence

Regards

Azza_B

Gday Accogan, I read the article but which part of the statement are you referring to? I was just trying to show that a lower cadence for the same power will require greater muscle force production i.e greater contraction strength. Which will make the type II the primary contributor once the type I have maxed out, forming lactact as a by-product from glycolytic sources. And in so reducing total efficiency.

A lower cadence will push you closer to your lactate threshold and therefore more easily past that threshold compared to a higher cadence assuming equal output is maintained.

mullerrj

Doc- now I'm confused. I thought the reason why my legs were spent was because of Lactate buildup or H+ ion formation. No? I didn't bonk at all..had good carb input throughout the ride. I was definitely riding in my Lacate Threshold Zone for a good portion of the 5+ hr. ride. I did an active recovery ride the day after..and on the third day..my legs were still spent..no zip..and they fatigued easily. So, I spent another day of active recovery. I have another century ride this weekend..and I'm just doing recovery rides until then. Is it because of my age (48) and it takes longer to recuperate? What really miffed me, is that the following day after my hard ride..I had no muscle soreness. I expected not to be able to walk up a flight of stairs. I don't get it. Maybe I'm confusing muscle fatigue with muscle soreness. All I can say is during the ride..my muscles were fatigued to the max. Can you elaborate more? Thanks Doc

Azza_B

Lactate causing muscle soreness is an old wives tale. Lactate or H+ does not result in tissue damage.

Lactate is a byproduct of glycolytic metabolism (used by type II An-aerobic fibres) and is an incredible fuel source for type I Aerobic fibres. The problem is that as lactate builds up you need sufficient MCT1 (the thing that carries the lactate accross a cell membrane) transporter cells to deliver this lactate to the type I fibres otherwise it builds up and dessociates into H+ which will denature specific enzymes that assist muscle contract and therefore produce fatigue.

The soreness is a reslut of broadbased tissue damage from the extensive load placed on each myofibril (muscle fibre) resulting in inflamation. Therefore you can almost count on the fact you will be sore when you stop (cool down) and this soreness will peak 48 hours after the activity becasue this is when the inflamation peaks.

The inflamatory process casues increased numbers of "substance P" to circulate around the muscle tissue which will sensitize your norci-ceptors (pain receptors), causing the post ride leg pain we all know and love.

Hence mullerrj if your getting this your training well and good on ya.

Az

mullerrj

According to Peter Janssen, MD, in his book "Lactate Threshold Training", muscle soreness is characteristic of increasing acidosis and high lactate values cause muscle fatigue. So, correct me if I'm wrong but isn't acidosis a result of the body not being able to neutralize the lactic acid increases in the working muscle? So, what was your issue with me saying what I did. My ride was not only long..it was hard..as hard as I've ever ridden before. Thanks Rob

mullerrj

Az, now I have to ask you a question after I asked Andy. After reading your explanation of why muscle soreness occurs (broadband tissue damage), isn't the reason for this occuring because of acidosis (caused by high lactate levels) seriously disturbing the various mechanisms in and around the muscle cells? i.e. acidosis damaging the enzyme system and wall of the muscle cell.

daveryanwyoming

According to an awful lot of published data, no. Take a look at some of these sites:
http://www.coachr.org/lactate.htm
http://sportscenteraustin.blogs.com...m_i_so_sor.html
http://www.nytimes.com/2006/05/16/h...eab85a6&ei=5090
http://www.sport-fitness-advisor.com/lactic-acid.html

Or google "blood lactate soreness" or other variations on the theme and you'll find a lot of discussion of why lactate isn't the problem and that the muscular microdamage is caused during the eccentric or lowering phase, not the concentric or lifting phase where the muscles are working hardest.

I'm in no position to debate your theories at the chemical level, but there's an awful lot of published work out there saying lactate is not the culprit.

-Dave

mullerrj

Thanks a bunch Dave..I too have read a lot on the subject..but I'll read all of the new links you sent me. Hey, I'm in no position to debate either..just trying to figure this all out. I've heard the same about Lactate not being the culprit..but everything I seem to read says it's an underlyer. To me, it's analogous to saying the reason the car ran off the road was because the tires didn't grab the way they should have..not because of the slippery wet road conditions.

mullerrj

Dave- here is a summary from one of the articles (above) supporting my claim: "Acidosis is thought to be a primary factor in muscular fatigue and is based on a good deal of research. Recent research is contesting this claim but it is still too early to dismiss acidity as a cause of fatigue". BTW, the muscular microdamage you refer to is DOMs, not the fatigue/soreness I'm talking about "during" High Intensity Exercise. In every one of the articles I read (from the links above), not one ruled out the possibility of acidosis being responsible for soreness/fatigue during exercise. Thanks again. Rob

doctorSpoc

I came up on this info a little while ago too... very interesting stuff.

there seems to many contributing factors to exersise induced fatigue (burning in legs) in medium and high intensity exersise and acidosis may or may play a small, large or no roll... but the kill switch seems to really reside in the brain. receptors in our muscles seem to detect certain conditions and this is sent to the brain as pain and greater and greater amounts of pain are used as a means to convince us to slow down.

what i would like to know is, is this to protect the muscle from damage (physical and/or chemical)? if one could block the brain from sensing the pain in ones legs and one could continue at a higher intensity than would normally be possible would this result in damage to tissue? what happens if the kill switch is removed?

in other words is there a really good underlying reason for this kill switch to have developed?

@ mullerrj - a clerification of a point in your summary... from the reports, it seems acidosis seems to be a strongly associated with fatigue in efforts lasting on the order of 1-10mins i.e. it may have a detrimental effect in the case of extreme acidosis

mullerrj

Doc..Believe it or not..I thought the EXACT SAME THING as you did after reading an article. Is it the kill switch going on in the brain that says, "ok, enough already muscle..slow down..if you don't I'll make you slow down with more pain/fatigue/etc." Then, I was thining just the same again..if that were true (how it works) I wonder if there was a way to detour the brains signal to the muscle..kinda like the relatively new FDA approved Relief Band (for motion sickness)..which sends an electronic pulse into your arm disrupting the brains signal that tells the stomach to vomit when your inner ear gets all whacked out from motion. If you could detour that brain signal to the muscle..telling it NOT to feel pain and/or slow down..you could essentially ride pain/fatigue free. That'd be WAY BETTER THAN EPO for endurance athletes huh?..easy to hide and hardly undetectable.

Interesting stuff..thanks for sharing. Rob

Skoorb

Lower cadence is tended to by recreational or new riders. Granted, some elites will use a lower cadence, but you'll find in most cases that the stronger riders have brought their averages up. It's a personal thing, but nothing one cannot test for themselves. In my case, I like generally to be at least 100 average over a ride, so even with hills that force it lower, I like to be around 105. This is time-trialing. I do find on longer rides when I'm really tired I naturally tend toward a low 90's cadence. Higher, though, really does seem to move some of the effort towards my cardio vascular system (which is strong--legs not so much, relatively).

One of these days I'll take my typical 15 mile time trial route and see what time I turn up doing 90-95, but I suspect it may not be great, and in any case even if it is, higher cadence seems to be easier on my knees. I do feel for brute power I can do the most at 100 or a bit lower, but the longevity of that is not good at all.

doctorSpoc

yeah, an FTP around 900-1000W ave would be kinda cool...

[edit] as long as your muscles didn't poach themselves or completely denature in the process... that part might kinda suck...