rate of protein absorption?

[nigh70wl]

OK - I am wondering if there is data, like, percentage absorbed per unit of time, so, rate of absorption on a timeline, for given types of protein - whey, casein, etc. I read on Wikipedia that casein forms a gel in the stomach and breaks down over a period of hours - but I'm thinking - is it a linear thing, like: it absorbs fully after 6 hours, and every minute of that 6 hours your body is receiving the same amount of protein? or, are there particular points on that timeline where it might spike - toward the end?

If that's a dumb question I apologize but that occurred to me earlier today, and I figured I'd see if you guys can shed some light on it.

[CajunPballer]

It's a dumb question in a way, and in a way not.

It is not, because everyone has a right to knowledge.
It is dumb if you are wanting the knowledge to apply to your training. Knit picking small things like that at this point in your training is a waste of time and energy.

That being said, the information is out there on the rates of digestion for the different types of protein. If I find it, I'll post it.

.

[nigh70wl]

lol yeah I don't think knowing one way or the other would affect the way I work out or consume protein. except it might persuade me to take some immediately before a workout, actually, that was one of the things that prompted this question - how much is actually broken down intra-workout as opposed to after. that, and wondering how long after you drink your whey it actually gets to your muscles. so, sort of a nutrition-related question, also a wanting-knowledge question

[CajunPballer]

lol yeah I don't think knowing one way or the other would affect the way I work out or consume protein. except it might persuade me to take some immediately before a workout, actually, that was one of the things that prompted this question - how much is actually broken down intra-workout as opposed to after. that, and wondering how long after you drink your whey it actually gets to your muscles. so, sort of a nutrition-related question, also a wanting-knowledge question

Well in regards to pre, intra, and post workout it's not a matter of rate of absorption but rather the NEED. The different proteins are broken down and absorbed at different rates, we all know this, but what is utilized is entirely up to the current demand for protein within the body. I'm probably wrong on this, but I think I read somewhere that whey protein is broken down and absorbed at a rate of 11g/hr and casein is 6g/hr. Whether or not you are in the middle of your workout or after won't affect the rate in which it is broken down, but rather what is utilized.

A good rule to follow to get the most out of your protein, without knit-picking:

1.5 hours pre workout: Solid meal with .25g per lb bw in carbs and protein and 25% daily value of fats.

.5 hour pre workout: Some sort of fruit. Good fruits are apples and satsumas.

Post workout: Most often debated. I have a protein shake, just because I'm usually thirsty. However, assuming you had an adequate PRE workout meal, you should still have a sufficient supply of calories and AA's for post workout.

1 hour post: Another solid meal similar to your preworkout meal.

.

[AFAN]

OK - I am wondering if there is data, like, percentage absorbed per unit of time, so, rate of absorption on a timeline, for given types of protein - whey, casein, etc. I read on Wikipedia that casein forms a gel in the stomach and breaks down over a period of hours - but I'm thinking - is it a linear thing, like: it absorbs fully after 6 hours, and every minute of that 6 hours your body is receiving the same amount of protein? or, are there particular points on that timeline where it might spike - toward the end?

If that's a dumb question I apologize but that occurred to me earlier today, and I figured I'd see if you guys can shed some light on it.

There are no dumb questions because we can all learn something from someone. According to studies and my biochemist, Calcium Caseinate can take up to 13 hours to digest with a trickle effect release of amino acids. There must be studies somewhere to check blood amino levels at intervals after ingestion?????.

[Trans_Isomer]

I would highly recommend reading Lyle Mcdonald's 'The Protein Book', it completely covers everything you asked about and more, its really the best book on proteins I have ever read, from absorption data, pre/intra/post nutrition, types of protein, etc.

http://www.bodyrecomposition.com/the-protein-book

To answer your question, proteins absorb non linearly (not a straight line on a graph), with proteins a bell curve is what you see on a graph, with for example straight whey having the fastest absorption times, thus a thin or narrow bell curve, with casein taking much longer to absorb, having a wider curve of absorption rate over time.

[SwissMuscle]

There are no dumb questions because we can all learn something from someone. According to studies and my biochemist, Calcium Caseinate can take up to 13 hours to digest with a trickle effect release of amino acids. There must be studies somewhere to check blood amino levels at intervals after ingestion?????.

13 hours is a bit of a long stretch, 7-8 hours is more likely since the amino acid concentrations start to rapidly decrease after six and half hours. There is a study that was conducted here in Switzerland (data below).

OK - I am wondering if there is data, like, percentage absorbed per unit of time, so, rate of absorption on a timeline, for given types of protein - whey, casein, etc. I read on Wikipedia that casein forms a gel in the stomach and breaks down over a period of hours - but I'm thinking - is it a linear thing, like: it absorbs fully after 6 hours, and every minute of that 6 hours your body is receiving the same amount of protein? or, are there particular points on that timeline where it might spike - toward the end?

If that's a dumb question I apologize but that occurred to me earlier today, and I figured I'd see if you guys can shed some light on it.

The data below should answer your questions (BTW there is no such thing as a dumb question, no one is born with knowledge)

Postprandial whey & casein Plasma Leucine Concentrations




"The speed of absorption of dietary amino acids by the gut varies according to the type of ingested dietary protein. This could affect postprandial protein synthesis, breakdown, and deposition. To test this hypothesis, two intrinsically 13C-leucine-labeled milk proteins, casein (CAS) and whey protein (WP), of different physicochemical properties were ingested as one single meal by healthy adults. Postprandial whole body leucine kinetics were assessed by using a dual tracer methodology. WP induced a dramatic but short increase of plasma amino acids. CAS induced a prolonged plateau of moderate hyperaminoacidemia, probably because of a slow gastric emptying. Whole body protein breakdown was inhibited by 34% after CAS ingestion but not after WP ingestion. Postprandial protein synthesis was stimulated by 68% with the WP meal and to a lesser extent (+31%) with the CAS meal. Postprandial whole body leucine oxidation over 7 h was lower with CAS (272 ± 91 μmolkg−1) than with WP (373 ± 56 μmolkg−1). Leucine intake was identical in both meals (380 μmolkg−1). Therefore, net leucine balance over the 7 h after the meal was more positive with CAS than with WP (P < 0.05, WP vs. CAS). In conclusion, the speed of protein digestion and amino acid absorption from the gut has a major effect on whole body protein anabolism after one single meal. By analogy with carbohydrate metabolism, slow and fast proteins modulate the postprandial metabolic response, a concept to be applied to wasting situations."

REF: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC25140/

[TheWaffleIron]

http://forum.bodybuilding.com/showpo...1&postcount=70

http://www.wannabebig.com/diet-and-n...a-single-meal/