Athletes and lactic acid?

Looking at the Olympics I couldn’t help but notice how much the commentators/presenters mention lactic acid build up in the muscles and how the athletes will have to get the acid massaged out.

I have a vague idea what they’re talking about but does anybody have a full answer to this ?

IANABiologist, but…

Under ordinary load conditions, muscles burn sugars with oxygen to produce energy (not going into the adenosine di- and tri-phosphates here). During strenuous exercise, however, it becomes impossible to get sufficient oxygen to the muscle tissue to support enough of this reaction to supply the required energy. At this point, muscle cells begin using another, much less efficient, reaction to produce energy–fermentation. This particular fermentation reaction produces, not alcohol (though it would be interesting if heavy exercise got you drunk!) but lactic acid. If the fermentation reaction is sustained, the lactic acid builds up faster than it can be flushed away. The acid causes soreness, stiffness, and can trigger cramps, so it’s a good thing to get rid of it. The massage presumably stimulates circulation so that the acid gets flushed away faster.

IANA biologist either, but the prior post, altho being partially correct, is not entirely so. First, you have to know that energy is produced by an organelle in your muscle cells called mitochondria. It is here in the mitochondria that energy is produced by the Krebs’ cycle (sometimes called the citric acid cycle, since that is one of the by-products, along with lactric acid). If there is enough O2 available, the cycle works fine, with glucose eventually returning to glucose. If there is not, excess lactic acid aggregates and is diverted into the bloodstream, where, eventually, it gets to the liver and is again converted into glucose. Lactic acid is always produced, being a later stage of the cycle, after pyruvic acid. The point is that with sufficient O2, it does not accumulate, as O2 is necessary for metabolizing it back to glucose.

The cycle involves the conversion of acetyl coenzyme A, derived from the glucose into H2 electrons,from which energy in the form of ATP is produced. There are many acids involved in the cycle, pyruvic, citric, and lactic being only 3 of them.

Balance had it right
Anerobic metabolism produces lactic acid. Massage can improve circulation, providing the oxygen needed to convert the lactic acid to pyruvate.

You had a few things not quite right, which I’m compelled to atempt to clarify, in the interest of fighting ignorance :wink: . I’ll put this simply, and perhaps generalize a bit too much, in the interest of clarity.

There is no “conservation” of glucose. Glucose is “burned” for energy. Perhaps you are thinking of oxaloacetic acid? That is “conserved”, in a sense - it is produced as the last step of the Krebs cycle, and used in one of the early steps (second). Kind of a chicken/egg thing. How did “we”, the very first time, use something we hadn’t produced yet? A question to ask stoned biology students.

The Very Simplified Krebs Cycle is:
Glucose is subjected to oxydative breakdown, producing 2 pyruvate molecules.

Pyruvate “loses” a CO2, becoming acetyl Coenzyme A (acetylCoA)

Acetyl CoA joins with oxaloacetic acid to form citric acid, and the cycle is off and running.
<skip several conversions>

alpha-ketoglutaric acid is converted into succinic acid and a molecule of ATP 9energy molecule )is produced. This is the whole point of the thing - produce energy for cellular functions - but instead of stopping here, a few more reactions take place to return the cycle to the starting point.

Succinate is converted into fumeric acid, which is converted into malic acid, which is converted - ta da - into oxaloacetic acid. The oxaloacetic acid is then ready to interact with acetyl CoA from the breakdown of the next glucose molecule.

actually, for those who really care, since each glucose produces 2 pyruvic acid molecules, the cycle spins twice, then is ready for the next glucose.

Lactic acid is only produced during anaerobic metabolism. I found a site which explains it better than I can…and lost the URL. Anyway,

Shaky Jake

This has been great info on lactic acid, but I seriously wonder about the benefits of massage that were mentioned in the OP.

Is it true that massage will cause the lactic acid buildup to be carried away faster than the circulatory system will do naturally? Are muscles generally being blood-starved if they don’t get a massage?

My personal experience is that massage feels great when my muscles are sore from exercise, but it doesn’t make the pain go away faster. The same goes for heating pads, Ben-Gay, etc. The only cure I’ve found is time.

I don’t have data/research to back up the benefits of massage, but it is possible - at least in theory. Massage will increase circulation to the affected muscle or muscle group, thereby increasing the oxygen delivered to the muscle, and facilitating the conversion of lactic acid to pyruvic acid and/or the transport of said lactic acid out of the muscle, into the circulatory system, and to the liver.

Try this: with your hand relaxed/outstretched (not in a fist), rub a finger over a knuckle on that hand for a minute or so. Notice how the knuckle is pinker than the others for a bit after you stop. This is hyperemia - increased blood flow. As to how much massage will help…I don’t know. I’m sure it helps some, as would a hot tub, or sauna. Massage would have the benefit of being targeted at the affected area. It’s not a cure, but a help.

Shaky Jake

#include IANAB.h

Once you feel soreness, the damage is already done–the tissue has already been injured by the acid buildup, resulting in swelling and pain. At that point the massage doesn’t really have any practical benefits. The point of the massage is to try to get rid of the build-up before it causes soreness, so the athletes won’t be hampered by it in the next race/bout/event/whatever.

It still makes a neat excuse for getting a massage when you’re a bit sore. ;D

Two of the presenters that have talked about this are Colin Black, a olympic silver madalist in the 400m and Sally Gunell(sp?), a olympic gold medalist in the 400m hurdles. They have both talked about massages after the pain is there but do say that the athletes need to get the acid worked out asap. These experienced athletes seem to think it is benifical. I would say that it’s to stop any further damage which may effect the athlete later on in the heats/finals.

Thanks for the answers :slight_smile: