Supplements and Endurance Sports – Part I

Supplements and Endurance Sports – Part I

Supplements and Endurance Sports
This is the start of a series of articles to cover the ever evolving world of supplements in endurance sports. There are so many supplements in the marketplace each claiming to provide a benefit. I hope I can provide some insight on different supplements and how they may work for you. With some of the claims, you never know if you are truly getting a benefit from what you are currently taking or if you could just be getting taken for a ride by false claims and marketing.

BCAA

Supplementation of the three Branched-Chain Amino Acids (BCAA) during exercise has been evaluated as a means to counter peripheral fatigue or central fatigue that impairs physical performance. The possible mechanism is that when consuming BCAA it will reduce the uptake of the amino acid tryptophan from the blood into the brain, which is where the tryptophan is converted to serotonin.

So by lowering the level of serotonin in the blood there helping aid in a reduction in central fatigue. But results showing a performance benefit have been in studies that were flawed either for methodology or not good control. More recently there has been studies that are very well controlled have not shown an exercise performance benefit in humans with BCAA supplementation. For the most part, the jury is really still out on BCAA performance benefits, but there has been some evidence that in conditions such as high altitude they may work.

Iron
If you have a shortage of iron in your diet and are an endurance athlete you can be impairing your performance. Iron is an important element in transporting oxygen in the blood and muscles. Having an iron deficiency such as anemia, or a low amount in your diet can weaken your aerobic metabolism by diminishing the amount of oxygen that gets transported to your muscles as well as reducing the capacity at which the muscles can use oxygen for production of energy. It also contributes to you maintaining a healthy immune system, and is required to produce red blood cells. Endurance athletes have shown they usually have a high loss of iron and will typically have high requirements. Some studies have shown that a male endurance runner may need ~17mg per day and a female ~23mg per day. Females are also at risk to low iron levels due to their menstrual blood loss. Vegetarians could be at risk as well. Consuming Vitamin C rich foods such as fruits or fruit juice will help aid in absorption of iron. Tea and coffee can inhibit absorption of iron. Typically athletes will see an anemic state when they begin training due to the increase of plasma volume in the blood, thus diluting the hemoglobin levels. But this should not affect performance as the body adjusts. If you do not get enough iron in your diet, you may need to take supplementation. Iron supplementation should be taken under medical direction from your physician or a registered dietician.

Whey Protein
Protein is definitely an essential nutrient in your diet, especially for an endurance athlete. Protein is needed to help build tissue, cells, and structural proteins in your body. Various sequences of amino acids make up proteins, and some amino acids are used as energy during physical activity. Whey Protein is a by-product of cheese, and is abundant of BCAA. Typically, you will consume enough protein in a proper diet. However endurance athletes typically have a higher need due to energy loss and recovery. This extra amount will also assist in repair of your muscles and stimulate protein synthesis after exercise. Recovery after each workout or race includes refueling, replenishing, and rehydrating. During exercise you will have protein breakdown, but during recovery it is the opposite, it is protein building (protein synthesis). If you consume protein immediately after exercise you increase your uptake and will help keep you in a positive protein balance. This window of opportunity is usually open for 24 hours post-exercise. Research has shown us that if you consume protein such as whey, combined with carbohydrate it will stimulate more protein uptake and absorption of amino acids. This will help muscle repaid and aid in replenishing your muscle glycogen stores (carbohydrate).

References:
1. Biolo, G., S. P. Maggi, B. D. Williams, K. D. Tipton, and R. R. Wolfe (1995). Increased rates of muscle protein turnover and amino acid transport after resistance exercise in humans. Am. J. Physiol. 268: E514-E520.
2. Biolo, G., K. D. Tipton, S. Klein, and R. R. Wolfe (1997). An abundant supply of amino acids enhances the metabolic effect of exercise on muscle protein. Am. J. Physiol. 273: E122-E129.
3. Davis, J.M., and S.P. Bailey (1997). Possible mechanisms of central nervous system fatigue during exercise. Med. Sci. Sports Exerc. 29: 45-57.
4. Gibala, M.J. (2000). Nutritional supplementation and resistance exercise: What is the evidence for enhanced skeletal muscle hypertrophy? Can. J. Appl. Physiol. 25: 524-536.
Gibala, M.J., D.A. MacLean, T.E. Graham, and B. Saltin (1998). Tricarboxylic acid cycle intermediate pool size and estimated cycle flux in human muscle during exercise. Am. J. Physiol. 275: E235-E242. 1998.
5. Hargreaves, M. (1997). Interactions between muscle glycogen and blood glucose during exercise. Exerc. Sport Sci. Rev. 25: 21-39.
Hargreaves, M. (2000). Skeletal muscle metabolism during exercise in humans. Clin. Exp. Pharmacol. Physiol. 27: 225-228.
6. Hargreaves, M., M.J. McKenna, D.G. Jenkins, S.A. Warmington, J.L. Li, R.J. Snow, and M.A. Febbraio (1998). Muscle metabolites and performance during high-intensity, intermittent exercise. J. Appl. Physiol. 84: 1687-1691.
7. MacLean, D.A., T.E. Graham, and B. Saltin (1996). Stimulation of muscle ammonia production during exercise following branched-chain amino acid supplementation in humans. J. Physiol. 493: 909-922.
8. Meredith, C.N., M.J. Zackin, W.J. Frontera, and W.J. Evans (1989). Dietary protein requirements and body protein metabolism in endurance-trained men. J. Appl. Physiol. 66: 2850-2856.
9. Rasmussen, B.B., K.D. Tipton, S.L. Miller, S.E. Wolf, and R.R. Wolfe (2000). An oral essential amino acid-carbohydrate supplement enhances muscle protein anabolism after resistance exercise. J. Appl. Physiol. 88: 386-392.
10. Rennie, M.J., and K.D. Tipton (2000). Protein and amino acid metabolism during and after resistance exercise and the effects of nutrition. Ann. Rev. Nutr. 20: 457-483.
11. Tarnopolsky, M.A. (1999). Protein metabolism in strength and endurance activities. In: D.R. Lamb and R. Murray (eds). Perspectives in Exercise Science and Sports Medicine, Vol. 12, The Metabolic Basis of Performance in Exercise and Sport. Carmel, IN: Cooper Publishing Group, pp. 125-157.
12. Tarnopolsky, M.A., J.D. MacDougall, and S.A. Atkinson (1988). Influence of protein intake and training status on nitrogen balance and lean body mass. J. Appl. Physiol. 64: 187-193.
13. Tipton, K. D., A. A. Ferrando, S. M. Phillips, D. Doyle, Jr., and R. R. Wolfe (1999). Postexercise net protein synthesis in human muscle from orally administered amino acids. Am. J. Physiol. 276: E628-E634.
14. Tipton, K. D., A. A. Ferrando, B. D. Williams, and R. R. Wolfe (1996). Muscle protein metabolism in female swimmers after a combination of resistance and endurance exercise. J. Appl. Physiol. 81: 2034-2038.
15. Tipton, K. D., B. E. Gurkin, S. Matin, and R. R. Wolfe (1999). Nonessential amino acids are not necessary to stimulate net muscle protein synthesis in healthy volunteers. J. Nutr. Biochem. 10: 89-95.
16. Van Hall, G., J.S.H. Raaymakers, W.H.M. Saris, and A.J.M. Wagenmakers (1995). Ingestion of branched-chain amino acids and tryptophan during sustained exercise in man: failure to affect performance. J. Physiol. 486: 789-794, 1995.
17. Wagenmakers, A.J.M. (1999). Nutritional supplements: Effects on exercise performance and metabolism. In: D. R. Lamb and R. Murray (eds.) Perspectives in Exercise Science and Sports Medicine, Vol. 12, The Metabolic Basis of Performance in Exercise and Sport. Carmel, IN: Cooper Publishing Group, pp. 207-260.

About Nick Suffredin:
Professional:
Previously I was an Associate Scientist at the Gatorade Sports Science Institute (GSSI). My primary responsibility was to support the GSSI physiology research program. I assisted with laboratory-based research projects focused on product efficacy and innovation to stay up to date on the emerging science in sports nutrition as it relates to physiological and performance responses. I primarily worked in the Human Performance Laboratory incorporating components such as sports nutrition, sport psychology, exercise physiology, motor behavior, biomechanics, and strength and conditioning. I also worked on testing elite professional athletes to enhance their hydration practices and nutrition intake to improve their performance. I was involved with research where I helped lead and design projects involving exercise/muscle recovery, exercise/athletic performance, carbohydrate metabolism, rehydration and dehydration, stress testing, body composition, gastric emptying, sensory perception, along with aerobic and anaerobic performance testing. I have been on human performance advisory boards to ensure and improve quality exercise programs and nutritional assessments with clear communication involving proper training and education.

Education:Originally I am from the suburbs of Chicago. I received his undergraduate degree in Movement Sciences from the University of Illinois at Chicago. After graduation I began an internship at GSSI where he helped assess the physiological and metabolic responses to fluid and nutrient intake before, during, and after exercise. I am currently working to earn my M.S. in human nutrition and food science with concentrations in sports nutrition and metabolism and then an M.S. in Applied Exercise Physiology with a concentration in thermoregulation.

Personal:I am married to my beautiful wife Melanie who also shares my passion with endurance sports and coaching. I was a collegiate athlete playing men’s varsity soccer. In my leisure time I am a competitive runner while also enjoying weightlifting, and playing soccer. I have coached elite endurance athletes along with providing them nutrition guidelines to follow.

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