While most athletes, bodybuilders in particular, will pay close attention to what they eat during the day, as well as their pre- and post-workout meals, there is relatively less attention paid to the period where we actually break our muscle fibres down - the workout itself. Many will drink water during their training while others will prefer carbohydrate based beverages. Quite a few will not drink anything at all, especially those performing low rep training. With this in mind let's look at a study (1) which examines how providing protein during a workout may impact muscle protein synthesis.
Objective: The group from Maastricht University in the Netherlands set out to measure the effect of protein co-ingestion with carbohydrates during weight training exercise.
Methods: Ten subjects were studied with the training sessions being conducted in the evening following consumption of a standardised diet during the day. Participants took part in two experiments, one where they were provided 0.15g per kg of bodyweight of a carbohydrate solution provided before the session and every fifteen minutes during the workout, and one where they were given 0.15g per kg of bodyweight of Peptopro (casein hydrolysate) on top of the carbohydrate solution.
Results: By consuming protein during the two hour long workout, protein breakdown rates were reduced by an average 8.4%, while protein synthesis increased by 33% compared to the carbohydrate only group. Whole body net protein balance was negative in the carbohydrate group but strongly positive in the group consuming protein during training.
Conclusion: Even in the fed state, protein co-ingestion increases muscle protein synthesis during resistance exercise.
Our Comments Intra-workout consumption of protein is a relatively new field and so does not have that much research behind it to date, something this study helps to redress. To date, the vast majority of research on consumption of drinks during training had been focused on endurance athletes who have very high carbohydrate and hydration needs. In the past, the supplement industry marketed similar products to weight trainers even though their needs are very different. One of the interesting facets of this study is that in contrast to the vast majority of nutrition studies, this one took place in the fed, as opposed to the fasted state. This is important to note as it has often been argued by sceptics that many studies showing a benefit to protein or amino acid ingestion only show a benefit because they were conducted in a fasted state. The fact the study showed a benefit for protein ingestion during the workout despite prior meals, lends support to those such as Charles Poliquin who have always advocated very high intakes of amino acids during training bouts.
For those who have had a high protein meal before training it is probably less important to worry about availability of amino acids during or after training, but many would not choose to have such a large meal before training as it can make it more uncomfortable to train and effect the potency of pre-workout supplements which many would prefer immediately before training. In addition, the very fast release rate of proteins such as Peptopro, BCAA's, and Whey Hydrolysate, make them an ideal intra-workout choice as they would enter the bloodstream almost immediately and cause less gastric distress than a whole food protein. For very long workouts it would become more important still to provide some fast acting protein source during a training session.
References 1. Beelen M, et.al (2008): Protein coingestion stimulates muscle protein synthesis during resistance-type exercise.