Strength athletes who consume slightly more protein than the recommended amount for non-athletes build up more lean body mass if they drink a post-workout shake containing whey rather than one containing soya protein. The renowned sports scientists Jeff Volek and William Kraemer draw this conclusion in a human study published in the Journal of the American College of Nutrition. The study is the longest that has ever been carried out on the effect of post-workout protein supplementation.
Strength athletes who consume slightly more protein than the recommended amount for non-athletes build up more lean body mass if they drink a post-workout shake containing whey rather than one containing soya protein. The renowned sports scientists Jeff Volek and William Kraemer draw this conclusion in a human study published in the Journal of the American College of Nutrition. The study is the longest that has ever been carried out on the effect of post-workout protein supplementation.
Athletes, trainers and scientists are still arguing about the best forms of protein for bodybuilders. Fortunately the debate is becoming more and more constructive, as more solid scientific studies become available. One example is the study by Volek and Kraemer.
The researchers wanted to know whether the type of protein that strength athletes use after a workout made much difference. In terms of its amino acid composition, whey is superior to soya, and it’s also a little bit quicker to digest. So on paper whey would seem to be a better post-workout preparation than soya protein. But before you can be certain of that, you have to test the hypothesis.
So the researchers did an experiment in which they got 63 men and women aged 18 to 35 to do weight training for nine months, and gave them a shake after every workout. All test subjects followed the same training schedule, training 2-3 times a week and consuming 1-1.2 g protein per kg bodyweight per day in their diet.
The researchers gave one group of subjects a shake that contained only the fast carbohydrate maltodextrin. Another group were given a shake containing 22 g soya-protein concentrate without isoflavones. A third group were given a shake containing 22 g whey concentrate. The shake meant that the daily protein intake of the whey and soya protein groups rose to 1.4 g protein per kg bodyweight.
On the days that the subjects did not train, they drank their shake at breakfast.
At the end of the nine months, the researchers could not detect any statistically significant differences in the strength progression between the three groups. Nor were there any significant differences between the groups when it came to the decrease in fat mass. There was however a significantly different effect on the lean body mass.
The whey-shake drinkers built up 3.3 kg lean body mass. The soya protein and maltodextrin users got no further than 1.8 and 2.3 kg respectively.
The factor that makes whey such an effective post-workout product is probably the amino acid leucine, which is present in large quantities in whey and not in soya protein.
The researchers discovered that the subjects built up more lean body mass, the higher the level of leucine in their blood in the early morning before breakfast. As you’d expect, the whey users had more leucine in their blood than the subjects in the two other groups.
“Daily supplementation with approximately 20 g whey protein during resistance training is an effective strategy for augmenting gains in lean body mass in young, healthy, untrained men and women consuming protein levels slightly above the recommended dietary allowance”, the researchers write. “Gains in lean body mass occurred in the context of stable or small decreases in fat mass. These results point to protein quality as an important determinant of the adaptive response to whole-body resistance training.”
Whey protein supplementation during resistance training augments lean body mass.
Volek JS, Volk BM, Gómez AL, Kunces LJ, Kupchak BR, Freidenreich DJ, Aristizabal JC, Saenz C, Dunn-Lewis C, Ballard KD, Quann EE, Kawiecki DL, Flanagan SD, Comstock BA, Fragala MS, Earp JE, Fernandez ML, Bruno RS, Ptolemy AS, Kellogg MD, Maresh CM, Kraemer WJ.
Abstract
Compared to soy, whey protein is higher in leucine, absorbed quicker and results in a more pronounced increase in muscle protein synthesis.
OBJECTIVE:
To determine whether supplementation with whey promotes greater increases in muscle mass compared to soy or carbohydrate, we randomized non-resistance-trained men and women into groups who consumed daily isocaloric supplements containing carbohydrate (carb; n = 22), whey protein (whey; n = 19), or soy protein (soy; n = 22).
METHODS:
All subjects completed a supervised, whole-body periodized resistance training program consisting of 96 workouts (~9 months). Body composition was determined at baseline and after 3, 6, and 9 months. Plasma amino acid responses to resistance exercise followed by supplement ingestion were determined at baseline and 9 months.
RESULTS:
Daily protein intake (including the supplement) for carb, whey, and soy was 1.1, 1.4, and 1.4 g·kg body mass?¹, respectively. Lean body mass gains were significantly (p < 0.05) greater in whey (3.3 ± 1.5 kg) than carb (2.3 ± 1.7 kg) and soy (1.8 ± 1.6 kg). Fat mass decreased slightly but there were no differences between groups. Fasting concentrations of leucine were significantly elevated (20%) and postexercise plasma leucine increased more than 2-fold in whey. Fasting leucine concentrations were positively correlated with lean body mass responses. CONCLUSIONS: Despite consuming similar calories and protein during resistance training, daily supplementation with whey was more effective than soy protein or isocaloric carbohydrate control treatment conditions in promoting gains in lean body mass. These results highlight the importance of protein quality as an important determinant of lean body mass responses to resistance training. PMID: 24015719 [PubMed - in process] Source: http://www.ncbi.nlm.nih.gov/pubmed/24015719
