About caffeine...

[zippetydude]

Kind of like Rob's question, I'm curious as to how others use caffeine (if at all). I was kind of surprised when I stumbled across this recently:

http://www.sciencedaily.com/releases/20 ... 232653.htm

Anyone have any further info on this, know any means of mitigation, or simply have thoughts on it?

For those of you who do long distances fairly fast (not necessarily a marathon) you may find this link interesting as well.

http://www.runnersworld.com/article/0,7 ... -0,00.html

Is this just a normal muscle getting a little sore from hard usage, or is real damage taking place? I consider Skyline equal to a marathon, so I think this question could be important to just about anyone on this board.

I'm not a doom and gloom person, so I consider these articles potentially valuable info in taking care of my body, but I'm not ready to stay home and give up all this fun outdoors. As this is a very astute group on this board, I would love to hear your thoughts.



z

[Rob]

z, the ScienceDaily.com summary of the Swiss study of caffeine effects on heart muscle blood flow left a few questions in my mind.

sample size (only 8 subjects in the simulated high altitude chamber)
subjects were all young
no commentary on diuretic effects of caffeine
no mention if blood was tested (02, CO2, pH, or viscosity)
no discussion of water intake
exercise duration not stated
no high altitude effects recorded (headache, swelling)

Nevertheless, the Swiss study gives us more to think about. Personally, I avoid caffeine when I know I'll be hiking on a crowded trail with no privacy.

[cynthia23]

Hi Zip, I had heard of this recent suprising news that caffeine may actually work against you in endurance sports, quite contrary to what has been previously thought.

Here is my take: studies on caffeine are invariably confusing and inconclusive. Recently, there have been theories that this is because different people, for genetic reasons, metabolize caffeine quite differently. (hence, the studies are always inconclusive or contradictory) For some people, it improves performance: for others, it dramatically worsens it. Apparently genetic differences between individuals determine how their liver processes a given drug--some are "low metabolizers" whose body doesn't eliminate the substance properly and hence build up to overdose levels rapidly, others high metabolizers who get rid of it too fast, etc. I'm grossly simplifying here, though, as it isn't all just about the speed of metabolization but also how the substance then affecst the total organism.

My understanding of pharmacology is, to say the very least, severely limited, but owing to having some negative effects when I recently attempted to take a common prescription medicine, I learned that researchers are now beginning to suspect that genetically-based differences in how individuals metabolize drugs are really quite profound and much more widespread than anyone suspected. A large minority of the population can't properly process many common drugs, and this is what we refer to as "side effects". It's now thought that this may, for example, explain why for most people, SSRI antidepressants are helpful, but for a significant minorit (twenty to thirty percent?) they may actually exacerbate the depression or cause mania. There is now some thinking that these metabolic-processing differences extend to "non-drug" substances like caffeine and alcohol, and account for the fact that for some these substances are innocuous or helpful, for others addictive and fatal.

I found (online) a lab that can do a genetic profile on you and find out how you metabolize caffeine, alcohol, and other substances--basically, tell you if these are substances you can safely/helpfully consume, or not.. Of course, it's very expensive (I think it was several hundred dollars.) At some point this may become a common medical test, however, because this has important ramifications for doctors prescribing medicines.

Meanwhile if you don't want to pay for a genetic profile, you could I suppose do certain kinds of empirical-self-testing (i.e. run with caffeine/run without.) It would be hard though because such tests would be highly subject to placebo effects. Perhaps if you had your own cardiology equipment you could directly test your heart but even this strikes me as subject to placebo or self-belief effects--heart rate, etc is easy to influence with emotional beliefs ...

Maybe there is an actual doctor or cardiologists on here who would like to take over with his/her professional thoughts ...I"m gonna go get me a Latte...