Which is better? Carbohydrate alone or an isocaloric amount of carbohydrate plus protein? Those old-school fools will tell you that all calories are the same. Let’s look at the facts. (Facts are stubborn things, you know.)
A recent study compared the effects of carbohydrate vs. carbohydrate-and-protein ingestion on multiple-sprint sport performance.1 Participants got an 8 percent carbohydrate or 6 percent carbohydrate plus 2 percent whey protein beverage every 15 minutes. The researchers found that the distance covered (4.2 percent) and maximal speed (6.1 percent) decreased in the final 15 minutes of exercise in the carb-only group, and that the carbohydrate-and-protein supplementation elicited a moderate improvement in each variable.
Those findings show that taking in carbohydrate and protein enhances multiple-sprint exercise performance above what you get with carbohydrate.
What about the question of protein feeding patterns? Is it better to spread out the protein, eating frequent small meals, or get it in large bolus feedings?
Scientists investigated whether feeding patterns of a whey-and-protein mixture taken before exercise affect postexercise muscle protein synthesis.2 Twelve resistance-trained males performed leg resistance exercise 45 minutes after commencing one of the following three treatments:
Placebo (artificially sweetened water)
Bolus (25 grams of whey protein plus five grams of leucine dissolved in artificially sweetened water; 1 x 500 milliliters)
Pulse (15 x 33-milliliter aliquots of the bolus drink every 15 minutes)
If that looks like Greek or Chinese to you, here’s the translation. The bolus is one 25-gram feeding. The pulse is small, equal feedings every 15 minutes, eventually adding up to 25 grams of protein plus leucine. The results are fascinating to say the least.
Muscle protein synthesis throughout five hours of recovery was greater with protein than with the placebo; however, there were no differences between the bolus or pulse groups.
The take-home message? At least in this case there really is no difference in muscle protein synthesis whether you spread it out or take your protein in one big feeding. For convenience, take it in one feeding. I mean who has time to sip on protein every 15 minutes?
As a practical matter, the most important meals of the day are the ones you have before, during and after your workout. Get some protein during one of those three windows. How much? At least 20 grams.
—Jose Antonio, Ph.D.
Editor’s note: Jose Antonio, Ph.D., is an assistant professor at Nova Southeastern University in sunny South Florida.
1 Highton, J., et al. (2012). Carbohydrate-protein co-ingestion improves multiple-sprint running performance. J Sports Sci. In press; published online ¡Nov. 8.
2 Burke, L.M., et al. (2012). Preexercise aminoacidemia and muscle protein synthesis after resistance exercise. Medicine and Science in Sports and Exercise. 44:1968-77.