How do you build lactic acids??
- Thread starter LabRat
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heckman
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I know when I used to cycle, Usually during a long hill climb or a sprint I would build up lactic acid in my legs so bad that they felt like they were on fire..I used to use cytomax to reduce the buildup of lactic acids..I don't know that it is something you want to increase if you don't need too.
einstein1905
New member
Lactic acid is the byproduct of anaerobic glycolysis. When oxygen is sufficient, your body breaks down glucose to make ATP. The more ATP you use, the more a particular muscle needs. There is only so fast your blood can supply a muscle with sufficient oxygen. When oxygen supply to a muscle is low, you make ATP from glucose in a very primitive, inefficient manner, with a byproduct being lactic acid.
To answer your question, you can do high reps to use up ATP or you can do low reps with higher weight to get the same result. Look at it this way; say you use (X)ATP per rep at a lower weight...multiply that number by the total # of reps. OR you can use heavier weight. Say using a heavier weight uses (2X) ATP and you multiply this by the number of total reps. What I'm saying is, you only have the ability to regenerate so much ATP while your muscles are oxygen deficient. It doesn't matter which way you go to get to the point of lactic acid production, if that's your goal.
The buildup of lactic acid is a sign that you worked your muscles, yes. However, the buildup itself is not a goal. In fact, proper stretching post workout helps to dissipate lactic acid buildup, which can be catabolic.
To answer your question, you can do high reps to use up ATP or you can do low reps with higher weight to get the same result. Look at it this way; say you use (X)ATP per rep at a lower weight...multiply that number by the total # of reps. OR you can use heavier weight. Say using a heavier weight uses (2X) ATP and you multiply this by the number of total reps. What I'm saying is, you only have the ability to regenerate so much ATP while your muscles are oxygen deficient. It doesn't matter which way you go to get to the point of lactic acid production, if that's your goal.
The buildup of lactic acid is a sign that you worked your muscles, yes. However, the buildup itself is not a goal. In fact, proper stretching post workout helps to dissipate lactic acid buildup, which can be catabolic.
homonunculus
New member
Einstein,
Could little things in there you might be interested in. (You were probably taught incorrect info. in your biochem class, TBH.)
Lactic acid accumulates in an anerobic environment, but it is produced during exercise primarily b/c the rate of energy demand (ATP use) results in allosteric activation of glycolytic enzymes at a rate that exceeds the mitochondria's ability to take up and oxidize pyruvate. Glycolysis is considered anaerobic when the fate of pyruvic acid is not acetyl-coA and mitocholdrial oxidation, but rather reduction to Lactic acid. This also serves the purpose of regenerating NAD+ so that glycolysis, which can provide ATP at a faster RATE (albeit not one that is as efficient as oxidative phosphorylation in converting bond energy into ATP, as you said). The point of lactic acid build up is to provide NAD+ as a substrate for glycolysis to continue to provide ATP at high rates (those that exceed the rates attainable with ox. phos.).
A phenomenon known as a lactate threshold occurs during aerobic exercise at approximately 60% (or even 80% if highly aerobically trained) of maximal oxygen consumption. This means that muscle and blood lactic acid levels will increase at higher levels of exercise AS WELL AS oxygen consumption. The lactic acid is accumulation not because muscle is anerobic (it still can use more oxygen and oxygen consumption does not decline or plateau, i.e., d/t aerobiosis), but because is it using ATP so quickly that "anerobic" glycolysis (and phosphocreatine) is required to provide the energy supply. (FYI, pO2 in the mitochondria at cytochrome oxidase much reach something like 2-3mmHg before oxygen levels are limiting for electron flow through the electron transport system.)
Naturally, anaerobic glycolysis cannot proceed indefinitely, as cell pH will decrease to a level that may slow enzyme catalytic rates (and inorganic phosphate levels will increase - probably a more likely cause of fatigue).
As far as your example of doing a lighter weight for X reps, vs. twice the load, etc.: the load used WILL make a difference in the accumulation of lactic acid, assuming sets are taken to failure. Just compare a 20 rep set with a 3 reps set (both to failure). If you want to produce more lactic acid, lighter weight (say 60-80% 1RM) will do this, vs. using heavier loads (85-100% 1RM).
What do you mean when you say, "In fact, proper stretching post workout helps to dissipate lactic acid buildup, which can be catabolic?" Are you saying lactic acid is catabolic, or stretching is catabolic?...
-Randy
Could little things in there you might be interested in. (You were probably taught incorrect info. in your biochem class, TBH.)
Lactic acid accumulates in an anerobic environment, but it is produced during exercise primarily b/c the rate of energy demand (ATP use) results in allosteric activation of glycolytic enzymes at a rate that exceeds the mitochondria's ability to take up and oxidize pyruvate. Glycolysis is considered anaerobic when the fate of pyruvic acid is not acetyl-coA and mitocholdrial oxidation, but rather reduction to Lactic acid. This also serves the purpose of regenerating NAD+ so that glycolysis, which can provide ATP at a faster RATE (albeit not one that is as efficient as oxidative phosphorylation in converting bond energy into ATP, as you said). The point of lactic acid build up is to provide NAD+ as a substrate for glycolysis to continue to provide ATP at high rates (those that exceed the rates attainable with ox. phos.).
A phenomenon known as a lactate threshold occurs during aerobic exercise at approximately 60% (or even 80% if highly aerobically trained) of maximal oxygen consumption. This means that muscle and blood lactic acid levels will increase at higher levels of exercise AS WELL AS oxygen consumption. The lactic acid is accumulation not because muscle is anerobic (it still can use more oxygen and oxygen consumption does not decline or plateau, i.e., d/t aerobiosis), but because is it using ATP so quickly that "anerobic" glycolysis (and phosphocreatine) is required to provide the energy supply. (FYI, pO2 in the mitochondria at cytochrome oxidase much reach something like 2-3mmHg before oxygen levels are limiting for electron flow through the electron transport system.)
Naturally, anaerobic glycolysis cannot proceed indefinitely, as cell pH will decrease to a level that may slow enzyme catalytic rates (and inorganic phosphate levels will increase - probably a more likely cause of fatigue).
As far as your example of doing a lighter weight for X reps, vs. twice the load, etc.: the load used WILL make a difference in the accumulation of lactic acid, assuming sets are taken to failure. Just compare a 20 rep set with a 3 reps set (both to failure). If you want to produce more lactic acid, lighter weight (say 60-80% 1RM) will do this, vs. using heavier loads (85-100% 1RM).
What do you mean when you say, "In fact, proper stretching post workout helps to dissipate lactic acid buildup, which can be catabolic?" Are you saying lactic acid is catabolic, or stretching is catabolic?...
-Randy
einstein1905
New member
homonunculus said:
Thank you....you know your stuff. I wasn't taught wrong- I just have forgotten too many details and tried to piece together what I did remember. Thanks for giving such an in depth answer. I love seeing this kind of stuff.
What I meant by lactic acid being catabolic, although not well worded, is the acidity conferred by the lactic acid will be anti-anabolic, rather than catabolic. Stretching will dissipate concentrations of lactic acid.
homonunculus
New member
einstein1905 said:
No problem, Big Guy. I have spoken with biochem. professors who are not exercise biochemists who will argue 'til they're blue in the face that lactic acid production is all about lack of oxygen (despite what I have said above). Heck, this lactate threshold is even observable in single isolated fiber contracting in media perfused with hyperbaric O2.
Ya know, probably the fastest way to dissipate lactic acid is to do very light exercise between sets. This oxidizes the lactic acid as well as ensures that there is a strong muscular pump to flush it out.
Don't know that stretching will do a very good job if the stretches are static and strong enough to really push the ROM. Just ask anyone who is doing a DOGGCRAPP inspired program which finished each rest-pause set with and "extreme" stretch. The burn is friggin' crazy.
The stretch, if strong enough (it doesn't take much to over come blood pressure - just ~40% of the muscles max voluntary force), will occlude blood flow and actually increase lactic acid in the muscle, due both lack of blood flow, and in this case, if the stretch is held long enough, d/t anaerobiosis!!! LOL.
-Randy
einstein1905
New member
homonunculus said:
I just saw a study about glut4 expression or translocation (maybe both) being affected by even a slight lowering of pH. I don't recall how long it took for lower pH to affect glut4 levels, and I also have no idea how long it takes for intracellular myocyte pH levels to return to normal.
homonunculus
New member
einstein1905 said:
Can't say I've seen that study, but it does not surprise me. If pH is reduced during exercise, glycogen is the main source of carbohydrate energy, so glucose uptake is not real concern, teleologically speaking, of the muscle cell.
Restoration of intracellular pH depends on cell mitochondrial density, muscle fiber capillarization, blood flow, how low the pH was, etc. Restoration of pH. will depend upon whether the exercise was steady state or not, but is typically complete within 5-20 min.
-Randy
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