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HalleluYAH
08-25-2006, 11:26 AM
Stimulation of Net Muscle Protein Synthesis by Whey Protein Ingestion Before and After Exercise
Kevin D Tipton1*, Tabatha A Elliott2, Melanie G Cree3, Asle A Aarsland4, Arthur P Sanford5, and Robert R Wolfe2

Timing of nutrient ingestion has been demonstrated to influence the anabolic response of muscle following exercise. Previously, we demonstrated that net amino acid uptake was greater when free essential amino acids plus carbohydrates were ingested prior to resistance exercise rather than following exercise. However, it is unclear if ingestion of whole proteins prior to exercise would stimulate a superior response compared to following exercise. This study was designed to examine the response of muscle protein balance to ingestion of whey proteins both prior to and following resistance exercise. Healthy volunteers were randomly assigned to one of two groups. A solution of whey proteins was consumed either immediately prior to exercise (PRE; n=8) or immediately following exercise (POST; n=9). Each subject performed 10 sets of 8 repetitions of leg extension exercise. Phenylalanine concentrations were measured in femoral arteriovenous samples to determine balance across the leg. Arterial amino acid concentrations were elevated by ~50% and net amino acid balance switched from negative to positive following ingestion of proteins at either time. Amino acid uptake was not significantly different between PRE and POST when calculated from the beginning of exercise (6722 and 2710 for PRE and POST, respectively) or from the ingestion of each drink (6017 and 6315 for PRE and POST, respectively). Thus, the response of net muscle protein balance to timing of intact protein ingestion does not respond as does that of the combination of free amino acids and carbohydrate.

HalleluYAH
08-25-2006, 11:30 AM
Here is the AA+CHO study referenced by the authors of the above study...


Timing of amino acid-carbohydrate ingestion alters anabolic response of muscle to resistance exercise:
http://ajpendo.physiology.org/cgi/content/full/281/2/E197

Author's Conclusion:
"The ingestion of a relatively small amount of essential amino acids, combined with carbohydrates, is an effective stimulator of net muscle protein synthesis. The stimulation of net muscle protein synthesis when EAC is consumed before exercise is superior to that when EAC is consumed after exercise. The combination of increased amino acid levels at a time when blood flow is increased appears to offer the maximum stimulation of muscle protein synthesis by increasing amino acid delivery to the muscle and thus amino acid availability."

whitedevil74
08-25-2006, 11:37 AM
Always you make informative post. Thanks for the heads up, so now is it recommended to just take EAA + Carbs before workout?

NATHAN518
08-25-2006, 11:50 AM
Stimulation of Net Muscle Protein Synthesis by Whey Protein Ingestion Before and After Exercise
Kevin D Tipton1*, Tabatha A Elliott2, Melanie G Cree3, Asle A Aarsland4, Arthur P Sanford5, and Robert R Wolfe2

Timing of nutrient ingestion has been demonstrated to influence the anabolic response of muscle following exercise. Previously, we demonstrated that net amino acid uptake was greater when free essential amino acids plus carbohydrates were ingested prior to resistance exercise rather than following exercise. However, it is unclear if ingestion of whole proteins prior to exercise would stimulate a superior response compared to following exercise. This study was designed to examine the response of muscle protein balance to ingestion of whey proteins both prior to and following resistance exercise. Healthy volunteers were randomly assigned to one of two groups. A solution of whey proteins was consumed either immediately prior to exercise (PRE; n=8) or immediately following exercise (POST; n=9). Each subject performed 10 sets of 8 repetitions of leg extension exercise. Phenylalanine concentrations were measured in femoral arteriovenous samples to determine balance across the leg. Arterial amino acid concentrations were elevated by ~50% and net amino acid balance switched from negative to positive following ingestion of proteins at either time. Amino acid uptake was not significantly different between PRE and POST when calculated from the beginning of exercise (6722 and 2710 for PRE and POST, respectively) or from the ingestion of each drink (6017 and 6315 for PRE and POST, respectively). Thus, the response of net muscle protein balance to timing of intact protein ingestion does not respond as does that of the combination of free amino acids and carbohydrate.
hal, did the "solution of whey proteins" contain carbs as well? it doesn't sound like it did...

Beast
08-25-2006, 11:55 AM
hal, did the "solution of whey proteins" contain carbs as well? it doesn't sound like it did...

No it didn't. The authors commented about this in the article and said that the insulin levels of EAA+CHO vs. Whey Protein were almost the same, so they do not think the CHO was the reason for the difference.

HalleluYAH
08-25-2006, 11:57 AM
hal, did the "solution of whey proteins" contain carbs as well? it doesn't sound like it did...
Probably not, but whey would be more expensive than AAs, so....

This is more likely a BV issue.

HalleluYAH
08-25-2006, 12:00 PM
No it didn't. The authors commented about this in the article and said that the insulin levels of EAA+CHO vs. Whey Protein were almost the same, so they do not think the CHO was the reason for the difference.
;)

NATHAN518
08-25-2006, 01:51 PM
No it didn't. The authors commented about this in the article and said that the insulin levels of EAA+CHO vs. Whey Protein were almost the same, so they do not think the CHO was the reason for the difference.
mehhhhh, i don't know...i guess they know more than i...but i would like to see this study include whey+carbs if we are comparing with EAA+carbs, yes, the insulin response is different, but still...we know that whey+carbs stimulates protein synthesis more than whey alone...i am not sure it is a fair comparison

TexAss
08-25-2006, 01:54 PM
OK Hall, you are getting way too smart here.

Thanks for all the digging, I think we're all benefitting from it.

SupaNatural
08-25-2006, 01:57 PM
Nice dig. Hal you're not a post whore so much as a thread whore. :p

pu12en12g
08-25-2006, 02:41 PM
I love some Purple WRAATH (EAA + Ergogenics) pre-workout... with or without carbs. It's even better pre-cardio IMO

Nice thread H

katma201
08-25-2006, 02:48 PM
I've been taking Beverly International MASS (amino acid tabs) pre-pre-workout for years now. It definately makes a difference.

deserusan
08-25-2006, 03:12 PM
Kevin D Tipton, Tabatha A Elliott, Melanie G Cree, Asle A Aarsland, Arthur P Sanford, and Robert R Wolfe Stimulation of Net Muscle Protein Synthesis by Whey Protein Ingestion Before and After Exercise. Am J Physiol Endocrinol Metab, Aug 2006.


DISCUSSION

The present study was designed to determine if the anabolic response of muscle to whey protein ingestion would be different depending on the timing of ingestion in relation to resistance exercise. There was an anabolic response to ingestion of 20g of whey proteins whether ingested prior to or one h following resistance exercise and no differences were detected between time points. The anabolic response to the protein ingestion was calculated in two ways. AUC of the net balance was determined from the beginning and for five h following the exercise bout. This method of calculating the response to timing of ingestion was similar the approach we used in ur previous study examining the response to timing of essential amino acid and carbohydrate EAA) ingestion (11). However, it could be argued that this approach biases the analysis in favor of the PRE trial because PRE had amino acids available for ~1.5 h more than POST. Even so, there was no significant difference between the two trials, although there was large variability in the response and some subjects did exhibit large uptake of amino acids by the leg when whey proteins were ingested prior to exercise. The response also was calculated for four h following ingestion of the whey proteins. This method provides an illustration of the basic response of the muscle to whey proteins before and after exercise. Unlike the response to EAA in our previous study (11), the anabolic response to whey protein ingestion was similar whether ingested prior to or following exercise. Thus, it seems that muscle protein accretion is stimulated by ingestion of whey proteins and the timing of the ingestion in relation to the exercise is not as important for this response as it was for EAA.

Previously, we demonstrated that ingestion of EAA before exercise resulted in a greater anabolic response than following exercise (11). It is not immediately apparent why free amino acids plus carbohydrate would engender a different response to timing of ingestion than whey proteins. The most likely reason that EAA ingested before exercise lead to superior amino acid uptake vs. following exercise was increased delivery of amino acids to the leg. In the present study phenylalanine delivery was not different between PRE and POST. The AUC for phenylalanine delivery was 4516 μMx5h/mL for PRE and 4913 μMx5h/mL for POST. If delivery of amino acids to the leg is a key component for the anabolic response, then these data suggest that it is delivery that explains the difference between the present study and our previous study (11). Our data do not allow a clear explanation of why amino acid delivery was greater for EAA ingested before than following exercise, but not different for whey proteins. It is tempting to speculate that digestion of the protein may limit the amount of amino acids in the blood during exercise when blood flow is high. Support for this speculation comes from examination of the amino acid concentration and delivery data during exercise. The increase in arterial amino acid concentrations during exercise was ~100% for EAA (11), but only ~30% for whey proteins when ingested immediately prior to exercise (Figure 3). Thus, the delivery of phenylalanine during exercise was increased by ~7.5X for EAA, but only ~4.4X for whey proteins. Therefore, this evidence suggests that amino acid delivery during exercise is greater when EAA is ingested than when intact whey proteins are ingested immediately prior to exercise. It is possible that consuming proteins at other time points prior to exercise, e.g. 30, 45 or 60 min, may have resulted in greater amino acid levels and increased delivery. Future studies should examine the response to ingestion of intact proteins at other time points before exercise.

There are several differences between the present study and our previous examination of the effect of the timing of ingestion of EAA (11) that may contribute to the different responses. Aside from the free amino acids vs. intact proteins, there was no carbohydrate added to the whey protein. It is possible that the insulin response to the carbohydrates influenced the response of muscle to timing of amino acid ingestion.[b] However, the insulin response to the whey proteins in the present study was similar to that to the EAA in our previous study (11). Thus, it is not likely that the differences in insulin response would explain the different responses of amino acid
uptake following ingestion of EAA or protein. In our previous study (11), we compared the response to ingestion of EAA immediately before exercise to immediately after exercise. In the present study, we compared whey proteins ingestion immediately before exercise to one hour following exercise. We chose one h because the response to ingestion of EAA at one h following
exercise (7) was slightly greater than immediately following exercise (11).[b] However, we cannot rule out the possibility that amino acid uptake from whey proteins would not be the same as EAA ingested at different times following exercise.

The difference in means between PRE and POST without statistical significance for the five h AUC suggests the possibility that our results are due to limitations in power and we have failed to detect a real difference between PRE and POST. Support for this notion comes from the fact that the EAA ingestion in our previous study (11) did result in a large, significant difference between PRE and POST. Thus, we expected the amino acid uptake for PRE to be superior to POST due to ingestion of whey proteins. Power calculations revealed that a statistically significant difference could be detected with twice the number of subjects – given the variability and difference between means. It is apparent that the large variability in the response of our subjects contributes to the lack of clarity. Careful examination of Figure 5 reveals that much of the difference between means is due to a very large response from one subject. If we consider this value to be a statistical outlier (>2 sd above the mean) and remove the value, the difference between means is reduced by >50% and it is less clear that our conclusions would be affected by a Type II error. Without this value, we would need >50 subjects to detect a difference. However, we cannot dismiss the possibility that we failed to detect a true difference between means for the five h AUC due to a small sample size.

Another interpretation of the data is that certain individuals are more responsive than others. Thus, the practical conclusion that ingestion of whey proteins prior to exercise will translate into significantly more accretion of muscle proteins may be true for some individuals. Whereas our study design does not allow a direct comparison for any one individual, it is interesting that four of the eight subjects in PRE had greater uptake over five h than any of the subjects in POST.

Other studies have examined changes in muscle mass with variable timing of ingestion of proteins in relation to exercise. Esmarck et al. (5) demonstrated that protein intake immediately following exercise resulted in greater muscle fiber hypertrophy than two h following exercise in elderly subjects. These data suggest that timing of protein intake may be crucial, at least in elderly subjects, but the data are not directly comparable to the present results since there was no pre-training protein ingested in the aforementioned study (5). To our knowledge, no comparison of protein ingestion prior to and following exercise has been made.

Thus, our two studies suggest that EAA and whey proteins may not engender the same response prior to and following exercise. Whereas it is clear that the response of muscle protein balance to EAA ingestion is superior when ingested prior to exercise, it is not clear that this is the case for whey proteins.

Tipton's studies are always flawed. This **** is almost laughable and the answer to the original topic is NO although I know it was a rhetorical question:) Please read the full study before quoting abstacts...........

NATHAN518
08-25-2006, 03:41 PM
I love some Purple WRAATH (EAA + Ergogenics) pre-workout... with or without carbs. It's even better pre-cardio IMO

Nice thread H
LOL, shameless plug :D

spoonman
08-25-2006, 04:05 PM
I have tried several EAA and BCAA supplements.

My conclusion is that in this point in time, the cost of these supplements and the hassle used to take them is not worth the benefit.

Diet is king and amino acids are just the building blocks of protein.

deserusan
08-26-2006, 05:08 PM
LOL, shameless plug :D

:)