A new study out of Japan has provided good evidence that timing of protein intake is an important determinant in the level of muscle protein synthesis following resistance exercise when comparing trained vs non-trained individuals. Although the study was published by a lone researcher from Hyogo University, it has a lot of value for both novice and experienced athletes.
To test his hypothesis, Hiroyasu Mori (the sole author) recruited two groups of males; one with a history of resistance training and one without. Between them the weight training group had trained on average for 6.2 years and generally performed resistance training two to five times a week. While subjects in the untrained group had only participated in recreational sports such as baseball or soccer two to three time a week, but had no prior experience in resistance exercise.
Each group was subject to a fairly standard 11 day resistance exercise program which consisted of 4 sets of 8 to 10 repetitions of leg press, leg extension, and leg curl on days 1, 5, and 9; bench press, shoulder press, and triceps pushdown on days 2, 6, and 10; and lat pull down, biceps curl, and rowing on days 3, 7, and 11. Day 8 was a rest day. All exercises were performed at 80% RM, and each set was followed by a 2-min break. To warm up subjects cycled for 10 minutes on a cycle ergometer at 100 watts.
Supplement wise, both groups received a whey protein and carbohydrate supplement either immediately following resistance exercise or 6 hours after. The supplements were devised according to bodyweight, with each subject receiving 0.3g/kg bodyweight protein and 0.8kg/kg bodyweight carbohydrate. Each subjects' diet was also controlled via means of a individualised targeted calorie controlled diet plans; devised by a registered dietitian. The researchers went as far as capping total protein intake for each individual at 1.5g/kg body weight (including intake from diet and protein supplement). What’s more, each diet was devised in line with total energy expenditure (TEE) estimated from daily activity questionnaires and in accordance with the Dietary Reference Intakes for Japanese and the Nutritional and Dietary Guidelines for Athletes. But what put the icing on the cake is that they even examined leftovers from meals to determine the actual calorie and nutrient intake during experimental periods.
The key take away from the study was that individuals with a history of resistance training don’t display the same level of muscle protein turnover following training as untrained individuals do. Practically this is evidenced by a lower nitrogen balance when protein is consumed several hours (i.e. 6) after weight training versus immediately in resistance trained individuals. Untrained individuals on the other hand still display strong muscle protein synthesis up to 6 hours after the weight training bout. To explain this phenomena, the author of the study cites evidence showing that levels of secreted anabolic hormones associated with muscle protein growth, such as testosterone and sex hormone-binding globulin, are lower after resistance exercise in long-term trained men than in untrained men. If follows that training status can play an important part in the level of muscle protein synthesis following weight training.
While the results of the study are intriguing and novel, when one reflects on the typical progression of your average newby in the gym versus the experienced trainer, its invariably the inexperienced trainer that accrues the mass more quickly. Intuitively, the experienced trainer needs to work much harder to get smaller, incremental gains that the guy who’s just starting out in the gym.
Mori H, et al. Effect of timing of protein and carbohydrate intake after resistance exercise on nitrogen balance in trained anduntrained young men. J Physiol Anthropol. 2014 Aug 6;33(1):24. [Epub ahead of print]