Checking John Kiefers citations for Carb Backloading?
I've seen John Kiefer misrepresenting the studies he cites for articles he writes. Has anyone fact checked his claims from the studies he cites in this link?
Posted Jun 4, 2012, 7:49 PM UTC
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Sometimes I think he skims over the research and draws a different conclusion to if you had really looked into the issue. Prime example: Acesulfame K: http://propanefitness.com/does-acesulfame-k-spike-insulin/
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After the workout, if not during, start loading carbs. The muscle tissue now has a high affinity for glucose, gobbling it up like a sponge,
Interestingly, I recently came across this paper that suggests (if I'm interpreting it correctly) that GLUT-4 content was measured to be increasing for up to 22 hours postworkout. I briefly looked at some of the citations in the article you linked where he talks about GLUT-4 and none of them mention that it's at the greatest immediately following pwo.
In fact, doesn't this study suggest that fasting or depriving carbs pwo increases insulin sensitivity in muscles even more? So wouldn't it make more sense to maybe carb-load the following morning (or even later)?
I also came across this post by some guy that seems critical of the whole CBL thing. Most of that is just nonsense about it not being a "realistic" diet to follow but he does make some points about the science of CBL that he backs up by some research. Admittedly, I don't know enough about nutrition to evaluate his claims. So I dunno if it's bs or not.
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Interestingly, I recently came across [1] this paper that suggests (if I'm interpreting it correctly) that GLUT-4 content was measured to be increasing for up to [2] 22 hours postworkout. I briefly looked at some of the citations in the article you linked where he talks about GLUT-4 and none of them mention that it's at the greatest immediately following pwo.
I think the main reason you only CBL for a few hours after the workout is to reduce fat gain. So conceivably you could CBL the day after working out instead of instantly after.
In fact, doesn't [3] this study suggest that fasting or depriving carbs pwo increases insulin sensitivity in muscles even more? So wouldn't it make more sense to maybe carb-load the following morning (or even later)?
I think most of this insulin sensitivity increase is from the deprivation of carbs which actually comes before the workout with CBL.
For the jimmy smith post most of his citations seem to show the reverse of what he is citing them for.
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Yeah, I was thinking fat gain would be the issue since insulin sensitivity in fat tissue would be high in the morning and he mentions lipogenesis is suppressed for only a few hours following the workout. But you could also sidestep those two issues by consuming caffeine + cardio in the morning, since caffeine lowers insulin sensitivity and cardio can also suppress lipogenesis. I realize that's much more complicated, but if done this way, wouldn't it result in a more optimal glucose uptake to the muscle cells?
Alternatively, since you didn't consume a fuckload of carbs pwo your insulin levels might return to normal much sooner and therefore lead to a higher increase in fat oxidation overnight, which might make up for any fat gain you accumulate if you eat carbs in the morning. This could also be one reason why both front loading and backloading carbs seems to work.
I think most of this insulin sensitivity increase is from the deprivation of carbs which actually comes before the workout with CBL.
Yeah, but would depriving carbs before the workout cause an increase in insulin sensitivity in muscle? That doesn't seem to make much sense to me, as I believe you would have exercise to increase insulin sensitivity in the muscle (and much greater increases if you deprive carbs pwo as this study noted).
For the jimmy smith post most of his citations seem to show the reverse of what he is citing them for.
Yeah, looking at it a bit more it honestly it looks like he just Wikipedia'd stuff (which I admit I did too but I'm not declaring anything or saying anything definitive) and copied and pasted. His claim that
Muscle contraction does stimulate glut4 activation but primarily in cardiac muscle and only to a lesser extent skeletal muscle
is right from the Wikipedia page on GLUT-4. I think he misinterpreted that, though.
These citations
When glut4 was measured post exercise, the quickest rise in it occurred 8 hours post exercise (4). Other studies showed the first spike upward of 22 hours post training (4) while one study showed no significant increase 4 hours after training (5).
don't seem to say the opposite. The last one is especially interesting. He might be cherry-picking, though, because I have seen a lot of studies supporting that GLUT-4 is in fact stimulated by muscle contraction.
His last claim is kind of interesting too
Your body has a way of making muscle glycogen even if that’s not our direct intention post workout (6)
This would kind of go in line with your other post about not finding evidence to support that carbs are necessary. I'm pretty sure I've seen similar claims in other studies, too.
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Yeah, but would depriving carbs before the workout cause an increase in insulin sensitivity in muscle? That doesn't seem to make much sense to me, as I believe you would have exercise to increase insulin sensitivity in the muscle (and much greater increases if you deprive carbs pwo as this study noted).
Fasting/abstaining from carbs increases whole body insulin sensitivity including skeletal muscle.
don't seem to say the opposite. The last one is especially interesting. He might be cherry-picking, though, because I have seen a lot of studies supporting that GLUT-4 is in fact stimulated by muscle contraction.
I did not check these ones.
Your body can make muscle glycogen from gluconeogenesis but if you are working out hard it will generally not be enough. And glycogen is not the only important factor for building muscle.
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I suppose then there is no difference in the order of which comes from first.
Your body can make muscle glycogen from gluconeogenesis but if you are working out hard it will generally not be enough. And glycogen is not the only important factor for building muscle.
Yeah I realize, and it does seem suboptimal if you're doing it that way.
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I've just finished looking through and most of what he says seems to track except for this part.
The 39th citation: http://jp.physoc.org/content/582/2/813.long
Only tests two groups, protein+carbs and nothing so I don't see how he can draw the conclusion that carbs are necessary.
The 40th citation: http://jn.nutrition.org/content/140/4/745.long
Doesn't really seem to say much about carbs being necessary for muscle growth either.