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General Climbing Discussion

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Lactic Acid Buildup 31-Jul-2003 At 1:28:06 PM fruityarse

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As someone who has studied extensively in this area, a few topics I wanted to add my cents' worth as well:

On 30/07/2003 Fi wrote:

>The products of this are ATP (energy), Pyruvic Acid and Lactic Acid. If the climber >was to keep climbing at this intensity, the Pyruvic acid and Lactic acid would build >up, resulting in blood pooling at the exercising muscle site. This is where cramp and >fatigue set in. For the body to keep going, it must drop intensity (to between 50-70%) >and the Aerobic system takes over. Here the byproducts are 38 units of ATP, Pyruvic >acid and water (which are both expelled form the body as sweat). Pyruvic acid and >lactic acid are toxic in high quantities, which is why it is sweated out, and lactic acid >can be broken down by oxygen (in the aerobic system phase).

I seriously doubt whether pyruvic acid and lactic acid are sweated out - sweating is a form of thermoregulation, not for the body's waste materials to exit the body - otherwise we would all smell poo-ey!!!!

>I would be looking at trying to delay the onset of 'hitting the wall' (ie. improving the >time from where LA is too much and the muslces tell you to stop) by working on this >energy system.

Am going to fight you on this one - "Hitting the wall" has nothing to do with delaying LA build up whatsoever. It is related to when your body switches to oxidising fat as your primary fuel source due to depletion of your body's carbohydrate stores. This happens during exercise of longer duration (min 90 minutes and above) and of moderate to high intensity (70% and above).

>The Aerobic system is improved by working at a lower intensity for a longer duration of >time (as Jac mentioned, laps in the cave; steady, relatively easy climbing; or >swimming/cycling). Also remember to stretch, which also assists in the removal of >lactic acid.

Lactic acid which is produced in a muscle where glycogen is broken down is either: 1)transported into the bloodstream, taken up by the liver and stored as glycogen. 2) transported to surrounding muscle fibres where it can be used as a fuel to sustain further contractions. Therefore - lactate produced DURING exercise can't be responsible for soreness and stiffness AFTER exercise. Within 15min of finishing exercise, lactic acid in muscles and blood are near resting levels.

Furthermore, stretching has not been shown in research to actually do this - purely anectodal...

>I'm not sure that Lactic Acid is responsible for causing muscles to 'swell', I can't say >I've heard of that before - that should be more due to the buildup of endorphins... but >muscles will definately cramp due to lactic acid build up.

True, lactic acid does not cause muscles to swell - muscle damage is what causes muscles to swell!

As for cramping, there are many theories as to why this happens - and lactic acid build up is one of the least accepted ones. Dehydration and salt loss are more generally accepted as culprits for cramping.

Hope that does not confuse people even more...

Cheers,

Bill