Does taking protein close to bedtime actually have a better anabolic effect than other feeding schedules? Ever since the original paper showing that the net leucine balance over a seven-hour period was more positive with casein than whey, folks have suggested that it’s best to take casein before bed—because of its slow-digesting properties.1 Let’s fast-forward to a nifty new study.
Scientists theorized that during prolonged resistance training, a time-divided intake pattern of a casein-based protein supplement would be more efficient than taking the same supplement immediately before each training session. That puts an interesting spin on nutrient timing. In a crossover study, 13 men aged 18 to 19 were evaluated during two well-controlled, eight-week training and supplementation periods.
Here’s what they did. Using TFR, as they called the time-focused supplementation regimen, subjects took the supplement in the morning and in the afternoon, immediately before their training session. The other method was called TDR, or time-divided supplementation, which included one morning dose, with a second dose in the evening, five hours after training. The daily dose contained approximately 70 grams of protein (82 percent casein) and less than one gram of carbohydrate and fat.
Results? The researchers measured a lot of things, including weight, body composition and one-repetition maximums for bench press and squat, before and after both of the eight-week training and supplementation periods. Of course, training produced a significant increase in 1RM strength in both the bench press (9.4 percent and 7.2 percent) and the squat (10.7 percent and 17.8 percent) in the TFR and TDR, respectively, with no significant differences between the two regimens. However—and this, my friends, is fascinating—fat-free mass increased 2.4 pounds with TDR, whereas no change was evident with TFR.2
I would not have predicted that. I would have surmised that the TFR method—morning, afternoon and preworkout—would have been superior because of the preworkout component. It looks like spacing out the consumption of casein and taking it prior to bed, however, may be a better strategy.
I’d suggest taking a fast protein, such as whey, pre- and/or postexercise, and taking casein before bedtime. That’s the best of all strategies.
Either way, the study throws a monkey wrench into the nutrient-timing strategy in that different proteins may in fact have applications that vary—for example, whey may be best for pre- and postworkout, while casein is best at night.
Editor’s note: Jose Antonio, Ph.D., is the CEO of the International Society of Sports Nutrition (www.theissn.org) and is a sports science consultant to VPX/Redline.
1 Boirie, Y., et al. (1997). Slow and fast dietary proteins differently modulate postprandial protein accretion. Proc Natl Acad Sci USA. 94(26):14930-14935.
2 Burk, A., et al. (2009). Time-divided ingestion pattern of casein-based protein supplement stimulates an increase in fat-free body mass during resistance training in young untrained men. Nutr Res. 29(6):405-413.