One of the most beneficial aspects of my many years of higher education is learning how to differentiate fact from fiction. As a 4x Ironman athlete, I have learned to take research with a grain of salt when it comes to fueling for endurance events. With several years of experimentation, all while trying to keep up with current research, I have learned that my training needs may differ from the athletes around me and my environment is not controlled like it is in a scientific test.
Because not every athlete is alike, I don't believe that there is one perfect diet out there that can be applied to every athlete. Sure, there are general guidelines that will encourage performance gains and weight loss/maintenance, but we all have different needs based on our training routine, body composition goals and lifestyle requirements. Because of that, we need to recognize our individual strengths and weakness when it comes to the diet and how we view the fuel that we put in our body.
In my latest issue of SCAN Pulse (Sports Cardiovascular, and Wellness Nutrition) from the ADA (Spring 2011, vol 30, no 2), the cover article featured Protein and exercise. As I have been mentioning in previous posts, there is an abundance of research dedicated to protein in the diet of athletes and that research is ongoing and somewhat inconclusive. Just like all research, there will always be new guidelines and new suggestions as researchers try to prove/disprove previous theories and hypotheses.
There was so much valuable information in this article that I just can't sum it up in one blog. I wanted to post a section that is of "hot-topic" with athletes, especially when it comes to discussions of how much protein to consume following exercise.
The appropriate amount of protein to consume following exercise is another important factor. Many espouse the old approach, "if a little is good for you, then a lot must be much better." Practitioners often recommend large doses of protein to stimulate the greatest muscle hypertrophy, but recent findings suggest there is a limit to the amount of protein that will effectively increase the anabolic response. Canadian researchers recently demonstrated that the response of MPS (Muscle Protein Synthesis) to increasing doses of protein following resistance exercise plateaus (Moore, Am J Clin Nutri, 2008). The response increased incrementally up to 20g, but no difference occurred in the response between 20g to 40g. Moreover, amino acid oxidation increased at the higher doses, suggesting that the excess protein was merely broken down and oxidized for energy. Thus based on this study, there is no reason to recommend ingestion of very large amount of protein (ex. >50g) following exercise.
Another situation in which nutrition may play a key role for athletes is with overreaching and overtraining. Many athletes find themselves in a situation where they have trained too hard and/or too long and their ability to train and perform declines. Studies suggest that increased carb intake may help ameliorate the symptoms of overtraining, but until recently no one had investigated the impact of a high protein intake (Witard, Med Sci Sports Exerc, 2010). Well-trained male cyclists dramatically increased their volume and intensity 1 week on two separate occasions (A protocol that typically results in a 10% decline in time trial performance). In one trial the cyclists consumed their habitual protein level (1.5g protein/kg body mass/d): in the other trial, the amount of protein consumed was doubled. Carbohydrate intake was clamped at 6g carb/kg body mass/d in both trials and the trials were isoenergetic. Decrements in performance, mood state and functional capacity of the immune system resulted in both trials. However, these declines were ameliorated during the high protein trial compared with the control. These data offer support for the concept that a higher protein intake may help attenuate the negative consequences of overreaching and overtraining.