Kettlebell Glycolytic training

[John K]

It is now known that lactate is formed even when there is sufficient oxygen for aerobic respiration - seems to be triggered by an intensity threshold...mostly - the body produces lactate even in a resting state.

When doing textbook Tabata HIIT the body in minutes can deplete muscle glucose to levels that would have supplied several hours of energy at a lower state - it is my understanding this is due to the glucose being used pretty much exclusively for type II fibers and very little is being oxidized (some of what is, being used to rephosphorylate creatine since lipid metabolism is suppressed). The body can mobilize glucose at a faster rate than is possible to use, at any level of activity, which is what makes this dynamic possible. This is why HIIT works best when the rate of activity exceeds ALL aerobic capacity (or as much as humanly possible). Most of what's left is converted to lactate and used throughout the body, a good bit of it recycled via Cori Cycle.



I don't know of any modern studies that demonstrated a solid link between lactate levels or even pH or H ion levels and contraction force. There are several that show buildup of inorganic phosphate from CrP impedes contraction. One study using muscle that lacked creatine kinase demonstrated that it could produce over a hundred contractions with no appreciable loss of force, while unaltered muscle started about 15% "stronger" but dropped to a fraction of its start force within 20 reps.



I could certainly be wrong about some of this, but from reading a lot of what's out there it seems like a fairly accurate layman's translation? The science is constantly updating, and I've changed my very limited (!!) understanding to build a picture of how different levels of glycolysis interact with CrP metabolism. I might be holding the book upside down...

Still working through lactate stuff. Do you have any links to lactate influencing CrP? That's the big thing I haven't seen yet. It definitely looks like current research by Brooks is focusing on lactate being the main goal of glycolysis. I haven't been able to understand why - I understand that lactate is cheaper energy than glucose, but I don't understand why you'd make pyruvate only to hydrogenate it ... so you can then dehydrogenate it and use it as energy. Perhaps you can clarify that?

 

[North Coast Miller]

Still working through lactate stuff. Do you have any links to lactate influencing CrP? That's the big thing I haven't seen yet. It definitely looks like current research by Brooks is focusing on lactate being the main goal of glycolysis. I haven't been able to understand why - I understand that lactate is cheaper energy than glucose, but I don't understand why you'd make pyruvate only to hydrogenate it ... so you can then dehydrogenate it and use it as energy. Perhaps you can clarify that?

I have no idea. Pretty sure what is now known is that lactate is converted at sites more or less directly on the outside and inside of the mitochondria. There might be some increase in energy or efficiency from the conversion back to pyruvate, or it helps remove another byproduct coming or going, or the conversion process itself generates an important signalling pathway? Most likely lactate also travels better/is more stable traveling from site to site, this would be a major bonus. I'm guessing here - my understanding breaks down pretty rapidly once you get past a fairly superficial level of chemistry.

I don't think that lactate influences CrP aside from rephosphorylation, but def CrP triggers/speeds up glycolysis. Glycolysis helps CrP ATP generation at least 2 ways, one of which is to clear out inorganic phosphate. Without this, even if CrP stores were still high, high levels of contraction force would drop off very rapidly, within 15 seconds or less.

Is somewhat ironic, because most people think glycolysis leads to a buildup of lactic acid and that's what "burns" and decreases contraction force, increases fatigue, etc while CrP is viewed as a super clean rocket fuel. The truth is closer to the opposite. As long as you are above threshold the alactic pathway soldiers on, generating inorganic phosphate as CrP becomes available, reducing contraction force for the same amount of ATP like dirt in the gears.

Ultimately it doesn't matter, the training methods don't change. If you want to maintain high levels of contraction force and speed you need to use brief efforts, lots of rest. In terms of harming yourself via glycolysis other than wasting training currency, its going to take a lot of time and effort, an uncommon amount really.