The Synergytraining Blog

The following is the first part of a 2-part report on the findings at this year’s exciting American College of Sports Medicine’s Annual Meeting…..

by Chris Mohr

I have summarized some of the recent studies presented at the American College of Sports Medicine Annual Meeting (ACSM). For those who are unfamiliar with this organization, ACSM is the largest sports medicine organization in the world. Each year at ACSM’s Annual Meeting, researchers, scientists, and health practitioners gather to discuss the latest happenings related to nutrition, exercise physiology, and rehabilitation, to name but a few. With that said, here are some abstracts I believe may help with achieving your health and fitness goals.

Post-Exercise Nutrition

This is such an important topic, with new discoveries practically each day, there was an entire session was solely devoted to it. Before I get into the studies, here’s a bit of background as to why these studies are of concern. Post-exercise glycogen repletion is crucial for performance.

Carbohydrates enhance glycogen repletion because it causes an increase in blood glucose and subsequently insulin. Insulin then shuttles the necessary nutrients into the post-workout nutrient depleted cells. The key is to cause a sharp rise in insulin levels to shuttle nutrients into the cells as quickly as possible, which facilitates recovery. Some recent studies have demonstrated that protein plus carbohydrate may enhance this insulin response; therefore, there is a potential that it may be more effective than carbohydrate alone for glycogen repletion. Moreover, protein is necessary to offset the negative nitrogen balance (protein breakdown) that occurs during and after a workout. With that said, here are three abstracts to take a look at this topic.

Abstract #0286
Post-exercise Muscle Glycogen Recovery is Enhanced with a Carbohyrdate-Protein Supplement
John M. Berardi, Thomas B. Price, Eric E. Noreen, Peter W.R. Lemon

The purpose of this study was to examine whether a carbohydrate-protein supplement ingested soon after recovery would enhance muscle glycogen (the storage form of carbohydrate) resynthesis better than carbohydrate alone. Remember that glycogen is the primary fuel source during exercise, so having optimal glycogen stores is crucial for workouts. The six subjects in this study cycled on an indoor cycle as intensely as possible for 60 minutes and the distance traveled was measured by the researchers. Then, one and two hours post-exercise subjects received either a liquid carbohydrate-protein supplement (0.8g/kg carbs/0.4g/kg protein), liquid carbohydrate (1.2 g/kg carbs) or a placebo (meaning it provides no energy at all, but makes the subjects feel like they are taking something). After six hours, the subjects’ glycogen levels were tested and it was determined that glycogen synthesis was greatest in the carbohydrate-protein groups vs. the other two.

However, despite these differences, there was no subsequent increase in performance. Take home message: a carbohydrate-protein supplement may enhance glycogen resythnesis more than an equal calorie carbohydrate drink; however, this does not translate into any performance improvement. The importance of protein post-workout probably comes into play with maintaining a positive nitrogen balance, which is otherwise difficult after a workout. More studies in this area are clearly necessary and the abstract below is one such study.

Abstract #0287
The Effect of Differing Post Exercise Macronutrient Consumption on Resistance Training-Induced Adaptations in Novices
Joseph W. Hartman, David Bruinsma, Amy Fullerton, Jenn G. Perco, Randa Lawrence, Jason E. Tang, Sarah B. Wilkinson, Stuart M. Phillips

The purpose of this study was to investigate the effect of post exercise consumption of milk (carbohydrate plus protein), soy (carbohydrate plus protein), or maltodextrin (carbohydrate only) on body mass, fat-bone free mass, and strength training during a 12-week progressive whole body resistance training program in men. One key to this design was that both the milk and soy offered the same amount of protein and calories, just not the same type of protein.

Subjects were randomly assigned to either the milk, soy or maltodextrin groups. They participated in a 5 day/week resistance training program and consumed their respective drinks immediately and 1 hour post-exercise after each training bout. There were no significant differences among any of the groups in any of the variables measured. Take home message: intact proteins (soy and milk) are effective at supporting muscle growth with no differences in those taking in no protein. While this study contradicts many I have seen this demonstrates that there is always room for research. Similarly, it’s important to remember that different types of protein may effect muscle and growth in different ways. For example, whey protein is absorbed more rapidly than casein (mainly found in milk) and soy, and therefore could make a difference in the outcome variables in this study and more importantly, be translated to greater results with folks in the gyms.

Abstract #0289
The Influence of Carbohydrate-Protein Mixtures on Recovery of Endurance Capacity
James A. Betts, Clyde Williams, Edwin Grey, Joe Griffin

While the majority of the Lean Body Coach Audience is probably more focused on strength training exercise than endurance exercise, I would venture a guess that there are some out there who this study may apply to. As mentioned earlier, glycogen is the primary fuel during exercise and the longer one exercises, the more glycogen that’s depleted. Therefore, it makes sense that endurance exercise will burn through glycogen like fire through tissue paper because endurance exercise can continue on for such an extended period of time.

The purpose of this study was to determine whether the ingestion of a carbohydrate-protein solution enhances recovery over carbohydrate alone (I’m beginning to see a pattern here with these studies). Seven men participated in this study. They each participated in a 90 min run with the intention of depleting glycogen stores. During the recovery period, subjects consumed a 9.3% carbohydrate solution, or a 9.3% carbohydrate plus 1.5% protein solution. Each group received this drinks at 30 minute intervals during a four hour recovery period. Subjects then completed a run time to exhaustion to determine if one drink enhanced performance over the other. First of all, the researchers were correct in that the insulin response was significantly higher and the glucose response was significantly lower in the carbohydrate-protein group.

However, this did not correlate to longer run times. What does this mean? Well, although performance itself was not different between the two groups, it does not mean the protein was not effective. The only blood measurements in this study were insulin and glucose levels. Protein synthesis could have been enhanced, which would subsequently result in a positive nitrogen balance, and ultimately enhance lean body mass preservation or building if that is your goal. Of course this is somewhat of a speculation on my part, but from all the literature I have collected in this area, it is a rather educated “guess.”

My current recommendation is to be sure you consume a post-workout supplement comprised primarily of about 3 or 4 parts carbohydrate with one part protein (e.g., for every 3 or 4 grams of carbohydrate, there should be 1 gram of protein). One great post-workout option is 1 cup of orange juice, 1 cup of water plus a scoop of quality whey protein, such as ProPlete Gold or ProV60. If you’re on a shoestring budget, some fat free chocolate milk would work as a quick, easy post-workout meal too. Whatever you choose, it should all be taken in as soon as possible after a workout to enhance recovery and prepare you for the next onslaught in the weight room.