|Image 1: Babies instinctively know how to grow - mother's milk (60% whey, 40% casein, at later stages) + sleep ;-)|
Pre-bed protein intake could be a crucial determinant of 24h protein synthesis
I guess, I won't have to tell you that bro-science has it that the most important thing to do before you go to bed (and for some hardcore "bros" even in the middle of the night) is not to brush your teeth, let alone to shower or at least wash your face, hands, feet and certain other body parts... no! The most important thing to do before you go to bed is to have a huge serving of protein - preferably a "night-time protein", like a slow-digesting casein-based protein shake with some additional fats to further slow the absorption (whether the fat will actually prolong the digestive process beyond what you will see if you ingest intact micelles, which will then be hydrolized in the gut and start clumping is anyone's guess, though). In fact, this is one of those truisms that has been repeated so often on the boards (and the ads) that you may be surprised to hear that Res et al. rightly claim that their study is the first one to investigate, whether this practice does actually povide any benefit for the professional or recreational lifter.
To this ends, the scientists recruited a group of 16 of the usual suspects, ah.. pardon "recreationally active men", which in this case means that they had a weekly physical activity level of 6.3h and 5.2h for the eight men in the protein and the seven in the placebo arm (#8 had a problem with a catheter, so that he had to be excluded), respectively. As you would expect from any study investigating the effect of dietary supplements on exercise performance and/or muscle growth, the subjects received a standardized dinner (0.04kcal/kg; 57% carbs, 13% protein, 30% fat) at the evening before the testing session, as well as "identical" (obviously the energy content was matched to the body weight of the respective individual) meals for breakfast, lunch and dinner on the day of the experiment. The overall protein content of the regular meals was 1.2g/kg body weight and should thusly at the lower end of what the "bros" would prescribe as a baseline protein intake for anyone trying to gain muscle.
Exercise protocol: Leg presses and extensions 8x8 - 45 min total
After a standardized meal at 4:45pm and a whole host of experimental procedures (most importantly to place the catheter for the multiple blood draws during the night), the participants performed 8 sets of 8 reps on a leg press and another 8 sets of 8 reps on a leg extension machine (2 sets at 55% and 65%, 6 sets at 75% of 1RM; "subjects were verbally encouraged during the test to complete the whole protocol"). Rest between sets was 2 min rest between exercises 5 min. At 9pm, ca. 15min after the exercise test, the subjects received a serving of Lucozade Sport Body Fuel and Lucozade Sport Recovery (yes, the study was supported by GlaxoSmithKline ;-), which contained 60g of carbs and 20g of whey and thusly mimics what many non-carbophobic athletes use to replete glycogen stores and ramp up protein synthesis after a workout. After a muscle biopsy at 11:30pm, the subjects received either 40g casein protein or placebo and "remained in a supine position until 0:00am" ... I lover this formulation, because it suggests that with all those catheters every subject fell asleep at exactly 0:00am after "remaining in a supine position" *rofl* - be that as it may, the scientists simply assume that their subjects had slept for 7 hours, when they woke them at 7am for the second muscle biopsy.
|Figure 2: Net protein breakdown, synthesis, oxidation (all left) and balance (right) measured over night in previously exercised subjects after receiving 40g of slow acting protein (casein) or placebo 30min before bed (based on Res. 2012)|
3.2kg of lean muscle mass in one year with nothing but a protein shake before bed?!
If we take a look at the abstract numbers the scientists measured, such as an increase in whole body (!) net protein retention of ~50µmol/kg (measured in phenylalanine tracer molecules) over the course of 7.5h and do some math, this tells us that a trainee who weighs ~80kg and followed this practice over the course of one year, where we assume that he trains four times a week (i.e. 208 sessions) this would allow him to store 832mmol or (if I did not miscalculate) ~146g of the phenylalanine tracer in the 208 nights following his training sessions... does that sound much? No, it certainly does not, but we just assume that for each of those phenylalanine molecules another molecule of each of the other EAAs was stored within the muscle (since we are talking about "whole body" protein retention, other organs will get their share as well, though), and further assume that they all weigh about the same (which is obviously bullocks) the 40g of casein every night would result in a net protein gain of 3.2kg! How does that sound?
|Image 2: Quark = Natural #1 casein source|
- Res PT, Groen B, Pennings B, Beelen M, Wallis GA, Gijsen AP, Senden JM, VAN Loon LJ. Protein Ingestion before Sleep Improves Postexercise Overnight Recovery. Med Sci Sports Exerc. 2012 Aug;44(8):1560-9.