Good for you!! That wasn't so hard, now was it? Maybe, more than one page of the literature might be the next step?


I have no idea what you are saying, or what your point is.

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Steve

http://www.PeaksCoachingGroup.com

Please explain how you would distinguish between the 2 on physical exam (no pre and post weights). I do believe in a good core temp reading - I had a pt with 107 recently - an adult no less. I also did not pack him in ice as that would be bad medicine (well depends on how you define pack.....). I also think pitting edema is useful. I'd love to learn some truly useful physical exam findings that show dehydration as I think the exam is rather useless for that (as unfortunately it is for most things - now you still need to do a good one but study after study after study has shown physical exam tests to be rather useless.......).

Also please let me know the sensitivity and specificity of orthostatic vital signs and how it changes the pretest probability of dehydration in a given pt. If you do that, you will quickly come to realize that orthostatic vitas signs are not particluarly useful as a test.

David

You have to look at this belief of Frank's in context.

His belief that VO2max is limited by peripheral factors and not the cardio/pulmonary system is the foundation upon which he explains how PCs "work". By forcing more muscle mass to contribute to the pedal stroke (i.e. the hip flexor groups) you can magically raise your power at VO2max as the cardiovascular system simply steps up its capacity to meet the increased demand. Quite simply, he has no other way to explain how his invention could possibly do what he claims.

that is not the case. if his invention reduced the amount of counter productive effort in the pedal stroke (1 foot resisting the other) it would do exactly what he claims.

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Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter

Actually, there is a bit of evidence for the 'brain is the limiter' thing--at least for some racing/training phenomena.
1. Some studies suggest that bonking actually occurs when the brain detects (for lack of a better word) that the glycogen stores are getting low (not yet gone) and this is, to some extent trainable.
2. The recent carbohydrate mouth rinse study, cited earlier, shows some of the same. The participants who used the tasteless carbohydrate mouth rinse performed quite a bit better than those receiving the placebo mouth rinse.

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Dick

Take everything I say with a grain of salt. I know nothing.

Here we go, it's the Frank and Andy show, again.

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Dick

Take everything I say with a grain of salt. I know nothing.

I'm a total idiot for getting into a pc debate, but I can't resist:

"counter productive effort in the pedal stroke (1 foot resisting the other)"

Please explain the foregoing statement. I'm confused because my legs and feet have pretty much the same mass. Thus, on conventional cranks my legs are balanced, as if on a see-saw. The mass of pushing leg serves to lift the rising leg. No (or negligible) effort is required to lift my rising leg. Except for chain-line losses (for which PCs do nothing) my pushing force goes to propulsion. What's the counter productive effort?

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It doesn't really matter what Phil is saying, the music of his voice is the appropriate soundtrack for a bicycle race. HTupolev

Well, it has been awhile since I have done some of this stuff at the pointy end of the stick but if you don't have left filling pressures sometimes you have to rely on less than perfect information. So, one can start with a history. If the patient is lucid the need for urgency is not so great. Part of the history should include asking weight. Most people doing a race have an idea what their weight was at the start of the race. and when was the last time they pee'd. Is the patient thirsty? If the patient is not lucid, then you have another story regarding urgency.

Then, physical exam would include

skin turgor
capillary refill
sunken eyes?
dry mucous membranes
sitting (legs dangling) or standing and supine blood pressure
is the patient moist or covered in dry salt
"measure" right filling pressure by looking at where jugular distention stops above heart level (the poor man's CVP)
look at respiratory variation in HR
temperature
weight

simple lab test could include a UA specific gravity and blood HCT.

There are rules of thumb regarding what the various physical exam findings mean regarding dehydration but I can't remember them. You asked about the orthostatic BP test specifically. As I remember a change of up to 10 mm HG is normal. If the change is as much as 20-30 mmhg you can be pretty certain dehydration is present. If more than 30 mm hg you can feel confident the patient is substantially volume depleted. I would suggest you ask an anesthesiologist in your hospital and I am sure they could help you out with better and more current rules of thumb in this regard.

Most of the "rules of thumb" are directed towards assessment in the surgery patient and not the athlete, but the principles should be similar. While no one sign is 100% certain, the more "positive" signs you have the more likely there is significant dehydration.

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Frank,
An original Ironman and the Inventor of PowerCranks

Let us get back to discussing whether there is a central limiter to VO2max, isn't that what the CGM states (it isn't called the central performance model CPM but the central governor model CGM)? Neither of those studies go the that "governor"point.

If he can produce a study that shows the carbohydrate rinse changes VO2 max, then I will believe Noakes might be on to something. And, I would still like to hear a mechanism to explain that study and it would be nice to see the study repeated and confirmed. Let us presume the results noted above to be true and real. Despite my asking no one has ventured forth a proposed mechanism as to how this mouth rinse study would cause this performance benefit effect. This study sounds like homeopathy. I guess it is possible it works the way Noakes claims, but the evidence for it is almost non-existant and there is no proposed mechanism to guide researchers.

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Frank,
An original Ironman and the Inventor of PowerCranks

Interesting theory and has some merit looking back over my training log this year. My idea of a taper is to take off the day before a race, and cut back mileage and intensity about a third the week before (usually). But the consistency of my training is such that a "taper week" is almost indistinguishable from the background of average weeks. Looking at what I considered my really good races this year, (and I race a lot but mostly short distances) I simply didn't go hard the last 3 days before the race and took off the day before. 4 days before my best 2-10-2 in ten years, about 5 weeks ago, I did a 10 miler on the trainer at what I consider to be my ftp. 6 days before last weekend's du where I placed 3rd overall, I did a 24 miler on the trainer at about 8 watts under my ftp. I didn't start out to ride that hard but it was a good night and I just kept upping the power. This brings me to another phenomenon, the post race training performances. That particular ride came the day after a balls out 10K where I didn't do great but didn't expect to because it was 6 days after the NO 70.3 where I slugged through a bare sub 2 hour 1/2 fighting cramps the whole way and was a walking wounded for the first 4-5 days after. That 10 miler at ftp came 3 days after another short du, a 2-12-2 and again, I wasn't trying to burn it up at the start but just felt good and kept upping the power. Back when I was young & foolish, (as opposed to being old and foolish now) I would occasionally do 2 races on a weekend and a lot of the time the second race was much better than the first. I know there's a theory that high intensity exercise triggers a short term rise in blood volume which could explain the second day performances but I'd be curious to know how long that effect would last.

JJ

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Every night that I run, the thought crosses my mind that there's no way in hell I'll still be running a month from now.

If you are not used to rest days, then never take one. Last year I tried to train without rest days, but if life gots in the way and I had one or two days off, I felt completely empty and slow. This year I take at least a day a week off. Now I can stand one or two days off without problems, so I don't "freak out" anymore if I can't train for one or two days. You can say you have to train doing nothing as well...

JJ,

After years of experimentation, this is what I arrived at:

• C race taper is train normally all week, just be discplined about sleeping properly and trying to get 56 hours of sleep that week
• B race taper is take Mon off/light, train normally (vol and intensity) Tue-Thu which typically includes "short course style intervals in all sports", take Friday light and Sat light with some intervals. Do a massive week of training from 14-8 days out
• A race taper is go super light from 14-11 days out, then train really really hard (intensity with moderate volume) from 10-8 days out, and then back on the B race taper

I don't change my diet or over hydrate, over salt in the lead up...the simple fact of reduced volume on Fri and Sat before the race tops things up. I think there is too much "changing of routine" going on for most people and then they are flat and cramping on race day....that's why better to do the "Changing of routine" from 14-11 days out and then get back into it.

Furthermore wrt cramping, I really think that the culprit is "reduced rest interval" on race day. Race efforts are continuous at higher than normal intensities. In an Ironman or half Ironman I take every possible opportunity on the bike to tuck and coast to drop my effort to zero watts and let my heart rate recover. I can also do this in XC ski races. I have found that this has taking cramping to "almost zero". You can coast parts of the swim by drafting, and even on the run, one can vary the effort at redline (depeding on race distance) or just below. Even at 10K pace, I might do some sections at 3:40 pace and then drop it to 3:45-3:50 pace for just 50 meters, which really can help some recovery take place. For the same reason, I also find a mildly rolling course faster than a completely flat course. There is no place to rest on the flat course unless one takes coasting breaks.

Personally, I think that our brains cannot concentrate continuously at high intensity (I could not even do it for 3 hours in engineering school during exams doing Fourier Transforms which involves no physcial component) and cramping is just the body trying to preserve itself after the brain starts getting tired sending signals to do the same difficult thing. Yeah, salt, heat and hydration all play into it, but I think "continously concentrating at red line" and not coasting is something new that happens exclusively on race day.

As such, I feel that racing frequently, or in the void of racing, doing weekly Time Trials are important to help one figure out how to throttle being above and below the redline in whatever sport and avoid cramping.

One a side note, I have never heard of anyone complain of cramping in swimming aside from in the calves. I have managed to eliminate that completely by doing a warmup run to get the calves going, so that i am not sprinting off the beach, diving in the water after doing some dolphin kicks and then cramping in the calves 2 min later, when all my blood is sucked up to my upper body.

"This study sounds like homeopathy."
Perhaps, but interestingly, in infants, sucrose given by mouth gives pain relief. This occurs almost instantly and the effect is blocked by Naloxone.
This would suggest that there is an endorphin response. Before the use of local anestesia for circumcision became more routine, we used to give sucrose with water in a bottle during the procedure and the crying was reduced by well over 90%. We started doing this when a study in the 80s showed such an effect and it worked as advertised.

Many endurance athletes report almost instant relief of bonking with Coca Cola, at least the old fashioned sucrose variety. This happens awfully fast to be explained by the rise in blood sugar, which takes a number of minutes. Is this the same type of thing.

Lastly, if I recall, one of the effects of caffeine is decreased 'perceived' effort. While this might be part of the systemic effect, caffeine certainly has lots of CNS effects.

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Dick

Take everything I say with a grain of salt. I know nothing.

so I don't "freak out" anymore if I can't train for one or two days. You can say you have to train doing nothing as well.

You know what they say when the really good coaches look at most people's training - the hard days were not hard enough and the easy days were not easy enough! :)

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Steve Fleck @stevefleck | Blog

I don't doubt that there are a whole host of effects that are poorly understood and might have real effect especially on psychological perceptions. There is no doubt the brain and our mental state can affect performance and perceptions (I once "cured" a severe and long-lasting spinal headache using hypnosis - the headache was gone when the patient came out of the trance). But, to claim that the nervous system somehow can affect physiological maximums really requires some sort of reasonable theoretical mechanism or incontrovertible evidence that it exists (where the mechanism would remain a mystery) before I can accept it. Neither of those are currently available

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Frank,
An original Ironman and the Inventor of PowerCranks

Furthermore wrt cramping, I really think that the culprit is "reduced rest interval" on race day.

30 years of endurance sports and I never cramped up except once( read on) in training or racing. Maybe I have been lucky. Maybe my metabolism/physiology has been well suited to this. For almost all of those years, I never gave a thought to salt supplementation. The only nod to it was that in Ironman races I would try and get a bottle of Gatorade in me every hour or so on the bike - that was about it.

The cramping incident happened in a bike road race, on a cool day I might add, two years ago. It was a 70 K race and I was a bit over matched in this race, but as you need to do when road racing, do EVERYTHING you can to stay with the front group. This meant repeated surges at max effort. There was also 10 minute stretch where I was away in a mini-break with two other guys and we were going full gas for much of this. We were unfortunatly caught and it came down to a bunch sprint for the win. I knew that I had little hope, but was prepared to have a go at it. Just as I was about to make my final jump with about 300m to go, I got out of my saddle and started to hammer - both my calves simultaneously cramped up. I had to back off at that point and just do what I could do to make it across the line. Race lasted about 2 hours and I was well hydrated throughout. I can only surmise that the cramping was the result of not really being ready for that type of riding and repeated on/off effort that you see in a bike road race.

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Steve Fleck @stevefleck | Blog

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Every night that I run, the thought crosses my mind that there's no way in hell I'll still be running a month from now.

Dave,
I appreciated your post and got a good chuckle .... probably one of those doc chuckles that you can only appreciate when you do this stuff all day long!

1) Docs working the finish line are idiots ... we do it for free and even provide our own malpractice coverage because we do it so the competitors don't all have to be sent to an ER and get a $2000 bill for services. I'm still fine with that and glad to do it when I can. All of those who are really ill are much appreciative.
2) I think we can do a fair job at judging fluid status ... for many of us its what we do all the time anyway.
3) I think I can recall what a tilt test is ... but I've never used it ;-) ... most of the people I see at IM can't stand up anyway so the orthostatic thingy becomes sort of moot. Most are hypotensive flat on their backs.
5) LOL with you .... its always amazing how incredibly smart we suddenly become when somebody really ill crashes and needs some real skill applied.

Frank ... I don't think you'd ever be the medical director at one of these events ... I just doubt it :-)

Duncan .... glad you got up from your crash at the finish. You did have medical care .... it was called UK socialized medicine ... and what you recieved is what everyone gets under those circumstances. Lucky there wasn't much wrong with you ... and what you had is fairly common.

Dave

Are you suggesting that cramping could be due to overdoing it on race day? Racing beyond your fitness level? Or doing things in races that we don't do in training???

BLASPHEMY!!!! Its gotta be some mysterious (or common) electrolyte/mineral that some of us need on some days in some races.....ask any lay person off the street and they'll tell you to eat more bananas or in this thread - drink more milk....

I read the ST rule book and it clearly states that all racing problems can be attributed to:

1) Nutrition and/or
2) Electrolytes

Please fix your post so you don't confuse everybody.

David

"I have never heard of anyone complain of cramping in swimming aside from in the calves."

I commonly cramp in the feet while swimming.. and have had quad cramps as well. However this is typically associated with going too hard trying to keep up with real swimmers in the Master's sessions; or in cold water; when undertrained. This fits perfectly with the new cramp theory of muscle fatigue and spinal reflex, outlined by Dr Noakes' graduates at
http://www.sportsscientists.com/...-cramp-part-iii.html
But that theory is not convincing when it comes to Monty and skid's experience..

While not available, it is certainly plausible that the brain monitors various parameters to keep us from killing ourselves.
(Are there other species that will willingly subject themselves to extremes of physical performance just for the hell of it.)

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Dick

Take everything I say with a grain of salt. I know nothing.

Are you suggesting that cramping could be due to overdoing it on race day? Racing beyond your fitness level? Or doing things in races that we don't do in training???

BLASPHEMY!!!! Its gotta be some mysterious (or common) electrolyte/mineral that some of us need on some days in some races.....ask any lay person off the street and they'll tell you to eat more bananas or in this thread - drink more milk....

I read the ST rule book and it clearly states that all racing problems can be attributed to:

1) Nutrition and/or
2) Electrolytes

Please fix your post so you don't confuse everybody.

Dave,

Brilliant. LOL :)

I was under no illusions on what had happened - I knew that the cuprit was - that I was not ready for that type of race. I needed to train more and I needed to do more specific kind of training so that I would be ready for those demands.

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Steve Fleck @stevefleck | Blog

"...I was under no illusions on what had happened - I knew that the cuprit was - that I was not ready for that type of race. I needed to train more and I needed to do more specific kind of training so that I would be ready for those demands..."

Come on Fleck...you're really shitting us now. Clearly without a powermeter to provide quantitative feedback, you have no clue whether you were at or exceeding your fitness on that day. The cramps could have been due to the alignment of the moon and the sun. Without a powertap, you have no proof. Now go raise your FTP by 20W :-) :-) :-)
Dev

A theory doesn't have to explain every instance of a phenomenon if a phenomenon can have more than one cause. It only need explain those that fall under its pervue.

Cramps seem to me to be some sort of discoordinated contraction. When I get cramps in bed in my calves or feet I am continually surprised as to how the muscle that is so painful seems to be hardly contracted at all. It certainly isn't a rock hard muscle. A "few" fibers gone haywire sure can get your attention. There is something about a cramp that is completely outside the normal muscle contraction regime. This explanation makes as much sense, if not more, than anything else I have heard.

I wouldn't be surprised if electrolyte abnormalities might make one more susceptible to cramps, but it doesn't seem they could be the only problem.

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Frank,
An original Ironman and the Inventor of PowerCranks

Sorry Frank - all those physical exam tests are relatively useless IMHO. You were likely taught physical exam skills/tests in an era/at a school that was very dogmatic. "This % blood loss causes this....". "You do orthostatics if you think the pt is dehydrated and they mean this...". These rules were passed down from generation of clinicians to generation of clinicians. Well, if you actually do studies - and test these "rules" or the dogma of medicine that has been passed from doc to doc - you find that they are wrong in many cases/lack sensitivity and specificity. Here are some examples - Homan's test for DVT = useless, Meniscal tests = useless, orthostatics = useless. You need to look carefully at the sensitivity and specificity of the tests (or positive predictive/negative predictive value) and the setting of the diagnosis you are looking for. Are you screening 100 IM finishers for 10 that are dehydrated? Are you screening thousands for the few with cancer?

Weight is great - but you rarely know a good pre-weight - and I specifically excluded it as its the only useful way to know how dehydrated someone is at the finish line (and even then it has problems). Skin turgor? Almost everyone over 60 has poor skin turgor and almost nobody under 40 does (unless they have cholera and are near death). Cap refill is full of false (+)'s and (-)'s as is orthostatics. I know of no connection with temp. Respiratory changes with HR???? Show me someone who can do that on physical exam - all finish line athletes will have high heart rates with little resp. variation I'd guess. JVP - VERY hard to get a group to agree on any measurement for that one. Dry mucus membranes - isn't everybody's mouth dry at the end of an IM? Moist or dried sweat - depends on the temp/how they finished the race/how long after the race they come to the tent/.....don't see much help there.

UA - I'd assume everyone's would be >1.030 - or at least most people who want an IV. Plus we are talking physical exam not lab. I doubt its available at the finish line....plus if they can give you a urine sample - they aren't that dehydrated probably.....

Hct - some people run 40 - some run 52 - can be useful if you know the pre-race value. Plus its a lab test and not applicable to our discussion.

History - can be useful in some cases but if they haven't pee'd in 6-10 hours does than mean they are 5% down or 10%+???? They'll also lie to get an IV.

Lucid? If the guy/gal is altered - different ball game and unlikely to be solely due to dehydration in this setting. I'd boot that one ASAP to the ER.

Back to my original point: I think its VERY difficult to tell on physical exam who is signifcantly dehydrated and who is mildy dehydrated.


David