Rule #3 You Need a Post-Workout Shake With Whey and a Fast Digesting Carb
Verdict: Post-workout protein is the way to go, while post-workout carbs may not be needed.
This OCD practice came about from the theory that there's an optimal nutrient profile for your first meal after a weight training session. These followers believe that this first meal needs to be digested as quickly as possible, which means it's typically in liquid form, comprised of fast digesting sources, high in protein and carbohydrates with little or no fat.
If all of those criteria are fulfilled then it's believed muscle protein synthesis and recovery will be optimized. Let's examine the research:
15 individuals performed 15 to 18 minutes of high intensity resistance training, consumed a complex protein beverage or carbohydrate beverage immediately post workout, waited 2 hours, and then performed a series of field tests (T-test, push-up, and sprint). Researchers did not find a significant performance difference amongst each field test across both groups, but found that across all field tests those who consumed the protein beverage had a significant cumulative advantage. [11]
27 untrained males consumed either a protein/carb drink before exercise, post-exercise, or received a placebo before/after exercise; the timing of ingestion of a protein/carb drink not affect muscle damage, function, and soreness. [12]
13 male and 16 female Crossfitters consumed protein/carb drinks immediately post-workout (40g protein/80g carbs for males and 20g protein/40g carbs for females) for six weeks; body composition, mean power, and sport-specific workout performance did not change compared to placebo. [13]
A review of past research studies found that 3-4 grams of leucine maximizes MPS, whey protein is an cost-effective way to obtain this quantity of leucine as well as other essential amino acids post workout, a fast digesting carbohydrate (e.g. maltodextrin or dextrose) appears to maximize MPS when consumed alongside a leucine-only supplement, and consuming an essential amino acid/dextrose beverage is most effective for increasing MPS prior to exercise. [14]
8 young resistance-trained participants performed 4 sets of knee extensions and 4 sets of leg press for 8-10 reps at 80% of their 1RM; 4 consumed 10g whey protein/21g fructose and 4 consumed 10g maltodextrin/21g fructose. The rise in MPS was greater in the whey protein/fructose group compared to the maltodextrin/fructose group, which suggests hypertrophy over time due to a positive net protein balance. [15]
Protein consumption post-weight training leads to a net positive protein balance, which increases MPS and leads to hypertrophy over time; high GI carbohydrates can increase muscle glycogen synthesis rates by up 61%; a 3:1 ratio of essential amino acids and high GI carbohydrates may increase arterial EAA concentrations 100-400% between 10 and 30 minutes post-ingestion. [16]
40 resistance-trained individuals consumed a post-workout shake comprised of 40g whey protein and either 120g of sucrose, honey powder, or maltodextrin; combining protein and carbohydrates significantly affects glucose, insulin blood levels, and post-exercise MPS but the type of carbohydrate does not have a significant effect. [17]
When 19 untrained males between the ages of 18 and 25 years consumed milk (protein and carbs) or a carbohydrate-electrolyte drink immediately post-workout for 10 weeks the milk group significantly increased their bodyweight and fat-free soft tissue mass compared to the carbohydrate-electrolyte beverage group. There were insignificant changes in IGF-1, cortisol, and resting energy expenditure across both groups. [18]
Consuming 20g of protein intra- or immediately post-workout maximizes MPS rates and consuming this protein alongside carbohydrates does not further increase MPS rates. [19]
Consuming 400ml of a 7.8% dextrose and 1.8% protein-electrolyte beverage increases muscle glycogen synthesis and MPS rates compared to placebo. Such enzymes measured include phosphorylation of Akt, mTOR, rpS6, and GSK3alpha/beta. [20]
Three groups, 8 healthy males per group, performed resistance training and either consumed 10g of whey protein every 1.5 hours for 12 hours, 20g of whey protein every 3 hours for 12 hours, or 40g of whey protein every 6 hours for 12 hours. Researchers found that consuming 20g of whey protein every 3 hours for 12 hours yielded the highest MPS during the 12-hour period. [21]
A meta-analysis performed by Brad Schoenfeld, Alan Aragon, and James Krieger found that consuming protein 1 hour pre- and/or 1 hour post-weight training did not significantly affect strength and hypertrophy-related adaptations. These researchers concluded that the increased protein intake rather than the timing of the protein intake led to any observed positive effects during the studies they analyzed. [22]
Bottom Line: For the average muscle head there's merit to consuming protein post-workout to maximize muscle protein synthesis. However stacking this with fast-digesting carbohydrates does not appear to increase MPS any further, but may maximize glycogen replenishment rates which may be beneficial for those perform 2x daily weight training sessions or endurance activities in addition to regular weight training. At the end of the day it's more important that the average muscle head consume adequate protein, carbohydrates, and calories rather than worry about the timing and composition of a post-workout shake.
Rule #4 You Need a Slow Digesting Protein Like Casein Before Bed
Verdict: Protein before bed is a good idea, but casein may not be needed.
This OCD practice came about from the theory that fast digesting protein sources such as whey protein are optimal pre- and post-workout whereas slow digesting protein sources such as casein protein are optimal prior to bed. Followers believe that the amino acids from casein are digested and released at a slower, more regular, and longer lasting rate compared to whey protein. This slower digestion supposedly will mean optimal anabolism and muscle protein synthesis while you're asleep. Let's examine the research:
16 healthy males performed one session of resistance training, consumed 20 grams of protein and 60 grams of carbohydrates immediately post-workout, waited 2.5 hours, and then consumed 40 grams of casein protein or a placebo 30 minutes prior to sleep. This consumption of casein protein increased muscle protein synthesis rates by 22% over placebo and improve net protein balance. Furthermore the rise in whole-body amino acid levels due to this casein intake remained for the duration of the sleep cycle. [23] Unfortunately this study did not compare casein to whey protein or a whole food protein source.
When 12 individuals consumed a casein protein beverage and 10 individuals consumed a soy protein beverage researchers found that glutamate, serine, histidine, and lysine amino acid uptake was higher in the casein protein group, but overall muscle protein synthesis did not differ between the two groups. [24]
Three groups of six healthy young males performed unilateral leg resistance exercises and consumed 10 grams of essential amino acids comprised via whey hydrolysate, micellar casein, or soy protein isolate immediately post-workout. These individuals also consumed their assigned proteins at rest; muscle protein synthesis was greater after consuming whey hydrolysate and soy protein isolate during both rest and post-exercise states compared to micellar casein. MPS was 93% higher after whey hydrolysate consumption compared to micellar casein. [25]
Bottom Line: These studies show that it's beneficial to consume protein post-workout and pre-bed, but casein isn't the best option if you're looking to maximize MPS. Although one study found that casein protein intake pre-bed kept amino acid levels high throughout the night it did not examine any other protein source. The average muscle head shouldn't worry about casein protein consumption pre-bed but rather focus on consuming some protein and perhaps a fat source to slow digestion prior to sleep.
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