понедельник, 10 марта 2014 г.

Whey only counteracts growth-reducing effect of alcohol a little

If you drink alcohol [structural formula on the right] after a training session it gets in the way of the anabolic processes taking place. Drinking a protein shake after the training session reduces this damage, but doesn’t get rid of it completely, write Australian sports scientists from RMIT University in PLoS One.

If you drink alcohol [structural formula on the right] after a training session it gets in the way of the anabolic processes taking place. Drinking a protein shake after the training session reduces this damage, but doesn’t get rid of it completely, write Australian sports scientists from RMIT University in PLoS One.
Lychees contain polyphenols such as cyanidin-3-rutinoside [structural formula shown below], cyanidin-glucoside, quercetin-3-rutinoside (better known as rutin) and quercetin-glucoside. [J Agric Food Chem. 2000 Dec;48(12):5995-6002.] Asian researchers have published regularly on the positive health effects of phenol-rich lychee extracts over the past six years.
If you drink alcohol after doing weight training, your muscles take longer to recover. That’s partly because alcohol deactivates testosterone.
Nevertheless, a lot of athletes drink alcohol after training. The researchers were curious to know to what extent post-workout whey supplementation could help to cancel out the anti-anabolic effect of alcohol.
The researchers got eight active men to do strength training leg exercises and then several cardio sessions on a cyclometer. The researchers put the cardio sessions together in such a way that the total workout model allowed for all imaginable types of training regimes.
An hour after finishing their training the men drank the equivalent of 12 units of alcohol. On one occasion the subjects were given 25 g maltodextrin after their workout, and 25 g maltodextrin four hours after the workout, when they had stopped drinking.
On another occasion the subjects were given two 25-g doses of whey instead of maltodextrin.
Alcohol inhibited protein synthesis, the researchers observed when they examined samples of the men’s muscle fibre. Whey [ALC-PRO] reduced this effect, but was not capable of restoring muscle fibre synthesis to the level achieved by drinking a whey shake but not drinking alcohol after training [PRO].
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Post-training alcohol consumption had virtually no effect on the amount of amino acids that reached the muscle cells. What it did do was to reduce the activity of anabolic signalling molecules like mTOR and p70S6K in the muscle cells.
“In conclusion, the current data provide the novel observation that alcohol impairs the response of muscle protein synthesis in exercise recovery in human skeletal muscle despite optimal nutrient provision”, the researchers write. “The quantity of alcohol consumed in the current study was based on amounts reported during binge drinking by athletes.”
“We propose our data is of paramount interest to athletes and coaches. Our findings provide an evidence-base for a message of moderation in alcohol intake to promote recovery after exercise with the potential to alter current sports culture and athlete practices.”

Alcohol Ingestion Impairs Maximal Post-Exercise Rates of Myofibrillar Protein Synthesis following a Single Bout of Concurrent Training.

Abstract
INTRODUCTION:
The culture in many team sports involves consumption of large amounts of alcohol after training/competition. The effect of such a practice on recovery processes underlying protein turnover in human skeletal muscle are unknown. We determined the effect of alcohol intake on rates of myofibrillar protein synthesis (MPS) following strenuous exercise with carbohydrate (CHO) or protein ingestion.
METHODS:
In a randomized cross-over design, 8 physically active males completed three experimental trials comprising resistance exercise (8×5 reps leg extension, 80% 1 repetition maximum) followed by continuous (30 min, 63% peak power output (PPO)) and high intensity interval (10×30 s, 110% PPO) cycling. Immediately, and 4 h post-exercise, subjects consumed either 500 mL of whey protein (25 g; PRO), alcohol (1.5 g·kg body mass(-1), 12±2 standard drinks) co-ingested with protein (ALC-PRO), or an energy-matched quantity of carbohydrate also with alcohol (25 g maltodextrin; ALC-CHO). Subjects also consumed a CHO meal (1.5 g CHO·kg body mass(-1)) 2 h post-exercise. Muscle biopsies were taken at rest, 2 and 8 h post-exercise.
RESULTS:
Blood alcohol concentration was elevated above baseline with ALC-CHO and ALC-PRO throughout recovery (P<0.05). Phosphorylation of mTOR(Ser2448) 2 h after exercise was higher with PRO compared to ALC-PRO and ALC-CHO (P<0.05), while p70S6K phosphorylation was higher 2 h post-exercise with ALC-PRO and PRO compared to ALC-CHO (P<0.05). Rates of MPS increased above rest for all conditions (?29-109%, P<0.05). However, compared to PRO, there was a hierarchical reduction in MPS with ALC-PRO (24%, P<0.05) and with ALC-CHO (37%, P<0.05).
CONCLUSION:
We provide novel data demonstrating that alcohol consumption reduces rates of MPS following a bout of concurrent exercise, even when co-ingested with protein. We conclude that alcohol ingestion suppresses the anabolic response in skeletal muscle and may therefore impair recovery and adaptation to training and/or subsequent performance.
PMID: 24533082 [PubMed - in process] PMCID: PMC3922864

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