Wildcard:
Apples and oranges. SCUBA vs Ironman. Someone who is hung over while on vacation getting cramps from something they don't do on a regular basis vs people who push human endurance to levels beyond belief. We can talk about one or the other....
Actually, the research I listed covers both "apples and oranges" pretty thoroughly. That said, countless divers of various fitness levels get cramps without being hungover, dehydrated, or low on potassium. Another article might help shed some light on where the information on the hydration/electrolyte theory has come from and how it relates to the original question:
http://www.physsportsmed.com/issues/1999/11_99/schwellnus.htm
Skeletal Muscle Cramps During Exercise
(Schwellnus; The Physician and Sportsmedicine 1999)
This provides detailed analysis of the various theories of cramping, including a historical timeline of the research. The dehydration and electrolyte theories were originally presented in the 1920-30's, and last presented in research in 1976.
It also presents a proposed mechanism by which calves cramp in swimmers:
"It is well known that the muscles most prone to cramping are those that span two joints. These muscles are often contracted in a shortened position during exercise--a fact that seems to confirm the role of inner-range contractions in muscle cramping. Contraction in this state produces decreased tension in the tendons of the muscles as well as decreased Golgi-tendon activity. The best example is a calf-muscle cramp in a swimmer. During swimming, the ankle is maximally plantar flexed as the calf muscle contracts. The tension in the Achilles tendon is decreased compared with the ankle in full dorsiflexion. Golgi-tendon activity is thus decreased in plantar flexion compared with dorsiflexion, resulting in less inhibition of the gastrocnemius alpha motoneurons."
Unfortunately, there is no research in the past 3 decades supporting dehydration and/or electrolyte imbalance as triggers for cramps during exercise, hungover or not.
Guru, is this a degree program? You claim you don't read fitness mags yet you advertise them in your sig line. No, I don't know who you are, nor do I realy care. I can post endless links to articles found online to make any point I wish too.....<snip>
Not trying to start a fight here...
Why would anyone get the idea that you're trying to start a fight? <g> Actually, I did not put the "Fitness Guru" in my personal info- that was put there by Natasha when I joined SB at her request. I was a little hesitant to accept, but she was doing it as a way of saying "thanks," and I thought it was a nice gesture.
My professional credentials come from the Amercian College of Sports Medicine, and certainly, it would be more accurate for my personal info to just say ACSM H/FI, or something to that effect. Ultimately, you and I are on the same team here, trying to help divers be healthier and safer.
The resources I've linked in this thread are not cherry-picked off random sites on the internet in an effort to support my position. They represent the only peer-reviewed research done on EAMC and indexed by the National Library of Medicine. You will certainly find websites that propogate the hydration/electrolyte hypothesis, even ones associated with medicine, but I have yet to find one that actually references their claims back to the research. Believe me, I've looked at this very thoroughly, because if telling someone to drink water and eat bananas will help prevent cramps, then I would be singing it from the highest mountain.
Now, would you disagree that good hydration and stretching before a dive will help to avoid cramps? Answer that as a given that the person has a decent C/V system and it is not hypoxia caused.
Hydration, no, for all of the reasons listed. Stretching, yes, as I've been saying all along. That's not to say that hydration is unimportant to divers, when in fact, hydration has a direct impact on blood viscosity and surface tension. Good hydration is thus probably important to good deco, but it won't keep you from getting a calf cramp while finning.
Add to stretching a program of conditioning, preferably one involving functionally specific movements, in order to delay the acute muscular fatigue that triggers EAMC, and you'll make great progress. This could be as simple as the exercises I show in my article on the subject (calf raise, etc.), or as far as doing pool laps with your fins on.
All that said, divers need to start with equipment that fits and technique that is sound- two points that others have made in this thread and I make in the article on my website.
You claim you don't read fitness mags yet you advertise them in your sig line.
In my sig line is a technically-reviewed book based upon the latest information on both exercise and diving physiology that took me two years to research and write. If you would've followed any of the links on the website, you would've seen that, not only was Dr. Michael Powell (aka "Dr. Deco") one of several technical editors, but other researchers and physicians in dive medicine (for example, the director of Dive Medicine at Thomas Jefferson University) have read this book and specifically commented on the technical accuracy of the information it contains. Note that nearly half of the book discusses hyperbaric physiology and how it relates to the physiological changes that an exercise program creates. It is far from a "fitness mag" or even a fitness book, for that matter. <g>
Cameron
