Wow vroom, these are great questions. This is such a misunderstood area of applied research that it really needs clearing up.
-muscles don’t take up nutrients unless there is a demand or a “push” (ie from insulin)
-during long term exercise, our energy comes from glycogen stored in the liver and fat. It gets dumped into the bloodstream and sucked upo by the muscle demand
-increasing muscle blood flow does not necessarily always feed the actual muscle cells. It’s pretty complicated, but you can have increased flow to feed the tendons and support structures. Unless you’re specifically looking at flow distribution, it will be generally be observed as “increased flow”.
-as mentioned earlier (buried in another post), the increased energy demand from exercise increases a substance in our muscles called AMPK. While this has many effects, the one that were concerned with is its ability to increase the number of glucose transport proteins at the muscle cell surface (insulin can do this too). More transport proteins equals more glucose uptake, even in the absence of insulin!
Great questions! I hope this helps!
[quote]vroom wrote:
Ack, all these name jokes, I think I’m going to Barrf!
Ha! Just kidding. Though I think there might be something in the post about inventing the concept of Barrbells. Might catch on.
Anyway, to get down to a question, I’m interested in muscles and their care and feeding.
Specifically, are they as picky as we think they are? For example, if blood happens to be flowing to them, and it contains nutrients, are the muscles going to react to that, or are they more passive, prefering to sit around waiting for insulin to push nutrients in?
I know blood flow is increased to muscles during exercise, and that is when they obviously need nutrients, but this is also a time when insulin usually isn’t in large supply – and they have no trouble keeping us going for hours on end (think cardio). It’s not all simply present in the muscle as energy stores is it?
Is increased blood flow to muscles inherently metabolism boosting? Will muscles generally find something to do with some quantity of energy with respect to growth or heat production if it is present?
Do we know what causes them to hoover in the nutrients, when insulin is not a factor?
I know this doesn’t appear directly related to anabolism, but during a time of growth, getting nutrients into the muscles will obviously be important… and I’ve seen you hint that some exercise may be needed to get optimal deliver in some of your other responses.
Anyway, I know this is all over the map, thanks for any thoughts you care to share.[/quote]