Assunzione corretta delle whey

[duchaine]

Non sono certo dell'affermazione iniziale del thread:

l'assunzione corretta delle Whey è nel post allenamento

.

Da un mio thread su di un forum americano (Lungo, noiso e mal scritto; quindi, vi consiglio di andare direttamente alle conclusioni in italiano!)

timing proteins: whey pre-workout?
Several years ago, nandi showed me a study (Tipton et al. 2001), where the authors concluded that "the response of net muscle protein synthesis to consumption of an EAC solution immediately before resistance exercise is greater than that when the solution is consumed after exercise, primarily because of an increase in muscle protein synthesis as a result of increased delivery of amino acids to the leg".

I discussed a lot with nandi, in private, about this study and he thought that a whey+carbs shake before workout could be a good solution to increase anabolism/reduce catabolism.
This is why (in Italy) I've suggested for several years to get a protein shake before w/o.

Recently, the authors of the previous research pubblished a new study, where the specificaly examine the response of muscle protein balance to ingestion of whey proteins (NOT EAA) both before and following resistance exercise (Stimulation of net muscle protein synthesis by whey protein ingestion before and after exercise, Tipton et al., 2006-2007).

Differently form what nandi (and I) thought, "amino acid uptake was not significantly different between PRE and POST when calculated from the beginning of exercise (67 ± 22 and 27 ± 10 for PRE and POST, respectively) or from the ingestion of each drink (60 ± 17 and 63 ± 15 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".


The authors can't exactly exaplain the different resault between the studies (and, as they admitted, these resaults surpised them).
The researchers had different hypotesys to explain the differences.

1)this is the most accredited hypotesis: "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. 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 but only 30% for whey proteins when ingested immediately before exercise (Fig. 3). Thus the delivery of phenylalanine during exercise was increased by 7.5 times for EAA, but only 4.4 times 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 before exercise."

It's important to notice what the authors suggest: "it is possible that consuming proteins at other time points before 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".

2)INSULIN. The authors write: "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. However, the insulin response to the whey proteins in the present study was similar to that to the EAA in our previous study . 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".

3)ERRORS IN MESAURAMENT: "
The difference in means between PRE and POST without statistical significance for the 5-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 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 two times 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 Fig. 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 5-h AUC due to a small sample size".

reading the research, my first thoughts are:
1) it's possible that whey before w/o it's not beneficial as I though, but it's not harmfull;
2)the study investigated proteic synthesys, not muscle catabolism. for a lot of reason nandi pointed out, it's plausible that whey before w/o reduces catabolism.
3)In every case, this study can be helpfull to optimize protein-timing.
it's important notice that the volonteers did 10 setX8reps.
I suppose that this w/o was about 30 min, just right the time a good whay needs to let the stomach.So, in the PRE-group, AA reach the bloodstream at the end of the w/o; while the POST group got the AA in the bloodstream 30 min post w/o.
Because the response to ingestion of EAA at 1 h following exercise (Rasmussen BB, Tipton KD et al., 2000) was slightly greater than immediately following exercise, I figure that the shortness of the w/o is a good reason to explain why the pre and post groups got similar resaults. Substantially, there is great affinity between the "pre-group" and the subjects that recived AA at the end of the w/o; while the "post group" showed great affinity to the subjects that recived AA 1 hour following the w/o.
Considering that a typical w/o is longer that 1/2 hour, I suppose that whey before training can be beneficial.
4)In very case, as the authors pointed out, "it is possible that consuming proteins at other time points before exercise, e.g., 30, 45, or 60 min, may have resulted in greater amino acid levels and increased delivery". this is plausible.
Taking some whey 30 min before w/o, in fact, should allow to get AA in the bloodstream just during w/o.
I suppose this tecnique can be beneficial especially good for people having a very short w/o.

Attualmente, quindi, sappiamo:

1)prendere un pool di aminoacidi essenziali liberi immediatamente appena iniziato l'allenamento AUMENTA la sintesi proteica;
1bis) che prendere il siero immediatamente prima del w/o SICURAMENTE non è dannoso rispetto a prenderli subito dopo l'allenamento;
2)prendere le prot del siero all'inizio del w/o FORSE può aumentare la sintesi proteica rispetto al prenderle dopo;
3)UN'ORA dopo l'allemento le prot danno risultati migliori di quelli che darebbero se prese immediatamente dopo.

Pertanto, ad oggi, personalmente:
1)prendo del siero un'ora prima del w/o e gli 8 EAA+BCAA e citrullina malata all'inizio dell'allenamento;
2)dopo un'oretta prendo del whey (anche se a volte non resisto e lo prendo subito, insieme a del glucosio)
3)oppure in alternativa a 2), mangio immediatamente dopo l'allenamento un pasto solido+bcaa (il che, considerata la lenta digestione di un pasto solido, ha, in termini di afflusso di AA al flusso ematico, lo stesso valore del siero un'ora dopo l'allenamento).

DUCH