"There's only one hard and fast rule in running: sometimes you have to run one hard and fast."

Wednesday, February 13, 2008

Peer Review

UMTR meeting

Yesterday, the Upper Midwest Trail Runners met; I expect either Wynn or Julie will give better details than I will, so I'll give the basics and my own strange take on things. The website's almost set, though we're asking a lot of Gretchen - when we got to differing types of wikis (I'd never heard there WERE types), she was saying, "This is pretty cutting edge, guys." It'll be up soon and I'll be taking registrations for the Fab 5 Fifties.

That is, if anyone actually enters.

I gave Larry my entry to the Superior 100. I'm first!

Because my ubiquitous t-shirts always get comments, I chose to wear an ultramarathon shirt from the year Wynn was born. 1981 Great Mille Lacs Run 100k, for the record. I DNF'ed.

My culinary skills needed to be proved, so I made a Key Lime pie with a gluten-free cookie crust. Those who ate it seemed impressed. Julie seemed impressed that there's a man who bakes. Gretchen made the rest of the meal, which is one of the perks of these meetings.

I bake and I'm free on Valentine's Day.


Saint Valentine, by the way, is the patron saint of prisoners, so the traditional thing to do is to visit prisoners on his day. I wouldn't bring flowers and chocolates, though. My tradition used to be to propose to Lori, but it's gotten old after a few years; haven't even spoken to her in the past 6 months. That's the last you'll hear about her, I expect. Also, for the record, she doesn't run, she smokes.

Muscle Fatigue

At the UMTR meeting, Phillip brought copies of the NY Times article about the latest findings about the origin of muscle fatigue. I spent 6 hours wrestling with the online article in the Proceedings of the National Academy of Sciences (PNAS). [I won't give the link.]There's a lot to cover here.

First, the PNAS should be abolished. Members of the academy are allowed a set number of publications per year, which they tend to trade with non-members for other favors. Articles by members are not peer-reviewed, so they can publish any crackpot idea - this is how the Linus Pauling "Vitamin C cures everything" got out. The main function of the journal is to let members publish quickly, so they don't get scooped by othe researchers and what gets published is what they couldn't get published elsewhere... bad science.

I stated before that lactic acid doesn't cause muscle soreness. The same team that "proved" that, ignoring those who beat them to it, say that muscle fatigue is caused by leaky calcium channels in muscle cell sarcoplasmic reticula. It's hard to see what's new in their study. Here's what happens:

When your brain decides to contract a muscle, it sends an electrical signal through the nervous system to the muscle cells. This signal, through a membrane protein, causes a change in the internal calcium concentration of the muscle cell. The calcium concentration change then triggers a cascade of events, starting with binding of calcium to the protein tropomyosin C, which then causes, with troponin, to move myosin physically, in a ratcheting motion, along actin molecules. This, happening in waves along muscle cells, is a muscular contraction. When the muscle relaxes, the calcium is dislodged from the protein complex and the myosin slides back to its original position.

When a muscle is contracted in quick succession, the calcium concentration doesn't vary as much, so the muscle doesn't contract as well. This is what causes the feeling of "dead legs," or muscle fatigue. What the paper points out is that repeated contractions cause the calcium storing portions of the cell (sarcoplasmic reticulum) to leak and that this leakiness takes a few days to repair itself - which is why you can't run hard every day. A study by Western Australia University of the runners who finished the 1000 mile run across Australia, looked for changes in blood chemistry and all they found was increased blood calcium, so it looks like cells try to compensate for increased intracellular calcium by pumping it out (which they do anyway, as the external concentration is always higher than inside).

The researchers developed drugs which seem to decrease this leakiness in mice muscles and there's speculation that this might lead to an ergogenic drug. The problem with testing on mice is that they weren't trained before the testing, so decreased leakiness may be a training effect that no drug would alter. We all know that training causes us to feel fatigue later and later or under greater and greater stresses.

There's a distinction to be made between the two meanings of the word "fatigue." The first is as in metal fatigue, a wearing down. The other is the feeling of tiredness. No explanation has yet been given as to why people feel tired after exercising. The wearing down of muscles is a fact; the continuous sliding of muscle proteins against each other leads to a frictional wear which has to be repaired; this wear and tear is what makes the muscles ache.

There are a number of chemicals that affect calcium in cells, including ryanodine, EGTA (a preservative found in many foods, not to be confused with EDTA, which is in everything) and A23187, all of which would be toxic in doses that would have an effect. Caffeine also has an effect, which I'll discuss at some point. Trying to alter the calcium levels in one cells won't work to make one a better athlete - that extra glass of milk won't help or hurt because of the calcium.
This actually leads into what I want to talk about next: frequency of hard runs. There's a lot more practical things to do than worry about calcium channels.

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