Protein Research Continues…
Scientists from Australia presented their work comparing a whey isolate vs. casein through resistance training on strength, body comp, and plasma glutamine.
Thirteen subjects were given either 100% whey isolate or casein protein (1.5 gm/kg body weight/day) and were simultaneously under the careful eye of researchers, who supervised each workout three days/week.
Interestingly, this group found that the 100% whey isolate was more effective at increasing muscle mass (~ 5 kg over 10 weeks) vs. the casein group who gained < 1 kg over the same time period. The whey group was also more effective at increasing strength and decreasing fat mass compared to the casein group.
Both proteins seemed to prevent the typical decrease in plasma glutamine levels that are common with exercise. With the simple addition of protein, these results surprise me; however, it is what it is and all research should be taken with a grain of salt.
In a study out of Shriners Hospital in Texas, researchers assessed the affects of essential amino acids (AA) and muscle protein recovery from resistance training exercise. This same group has published their data demonstrating the benefits of 6 gm of AA in addition to 35 gm of sucrose on muscle protein synthesis; however, the effect of AA alone remains elusive.
Subjects performed a resistance training bout consisting of 10 sets of 10 reps of leg press and 8 sets of 8 reps of leg extension (not sure how they came up with this particular protocol, but that's why it's their study and not mine). Each subject then received 0.087 gm of essential AA/kg body weight. They learned that this supplement stimulated muscle protein synthesis following exercise and arterial EAA concentrations increased several-fold following drink consumption (16).
