As all athletes know, performance is an optimised combination of technical training, recovery phases, efficient muscle mass, a healthy lifestyle with good hydration, as well as a balanced diet.The diet must cover the major nutritional requirements in water, micronutrients, carbohydrates and proteins made of various amino acids.Some of them are particularly precious for athletes: focus on leucine and tryptophane.
The role of proteins during and after exertion
Proteins, essential for our physiology and balance
Proteins are macronutrients just like carbohydrates and lipids. essential to our bodies and play more of a structural role, making up muscles, tendons, collagen, skin and bones.
Proteins are also involved in the highly numerous physiological processes for the proper functioning of the body, such as the immune system with antibodies, the synthesis of DNA with nucleotides, the transport of oxygen in the body with haemoglobin, or hormones such as insulin and glucagon, which are involved in the regulation of the blood sugar level of athletes.
Proteins make up 10 to 12 kilos of the body weight of an adult male, of which 250 to 300 grams are synthesised each day. Nearly 40% of our bodies' proteins are found in muscles.
Proteins, muscles and movement
Composed mainly of protein, muscles are a set of contractile fibres attached to tendons for moving joints and thus generating the movements of the body.
Certain types of intense physical exertion damage the muscular fibres, degrading the proteins of which they are composed. What is more, certain amino acids are also consumed for energy purposes. These processes are known as catabolism.
This is the reason the body has a system for continuously renewing muscular fibres, called anabolism. The effectiveness of this system depends on the availability of amino acids, on glucose which provides energy for reconstruction and on the influence of certain hormones.
Proteins, nutrition and performance
This is why a daily protein intake is essential for the proper functioning of the body, to develop an efficient muscle mass for movement and performance. Indeed, the body can produce proteins (DNA, myoglobin, insulin, antibodies) and muscle fibres only from those that we have consumed in food. Thus milk, dairy products, meat, fish, eggs, legumes or tofu are excellent sources of protein.
An intake of protein and amino acids after exertion promotes muscular reconstruction in athletes. The 30 minutes following exertion represent a metabolic window, meaning a time that is favourable to the absorption of nutrients and to recovery.
A post-exertion snack should contain proteins whose amino acid content is made up of at least 40% essential amino acids, including 20% of leucine, an amino acid which plays an essential role in the anabolism of muscle protein.
Also, whey proteins, which athletes frequently consume, are rich in leucine, which acts perfectly within the famous metabolic window of 20-30 minutes after exertion!
Now let's focus on leucine and tryptophane, two essential amino acids of particular interest for good recovery.
Leucine and tryptophane: two essential amino acids
Leucine, a branched-chain amino acid (BCCA), a source of energy for muscles
Did you know that leucine makes up 8% of the body's amino acids? Just like isoleucine and valine, it must be provided by food and forms part of the "branched-chain" amino acids, so-called because of their structure.
Leucine is essential for athletes because it has anabolic properties for muscle building and anti-catabolic properties to preserve existing muscle fibres. This amino acid contributes to the assimilation and synthesis of proteins. It acts in concert with the other BCAAs to prevent degradation of muscle and of the glycogen stores. Thus, leucine enables longer periods of training and improved recovery after exertion!
In concrete terms, you should take care to consume food rich in leucine, such as dairy products, meat, soya and spirulina. Otherwise, it is recommended to take a leucine supplement during meals to more efficiently absorb the proteins in the meal, or to take a leucine supplement with sports nutrition products made with 'native whey', which is naturally rich in leucine. But perhaps you are already eating it without being aware of this? Leucine is also used as a natural food additive, as it gives a sweet taste to formulas.
Did you know ?
A new study carried out by researchers for the US Army studied the effect of a drink consumed during exertion which contained 10 g of the 8 essential amino acids and 1.87 g or 3.5 g of leucine.
The result of the study showed that the drink enriched with leucine accelerated protein synthesis by 33%, thus improving muscle recovery.
This study also shows that the benefits of proteins for muscles are not reserved for athletes in strength sports but also those in endurance sports.
A drink rich in BCAAs, leucine and glutamine can optimise muscle recovery when it is consumed as soon as possible after training. In case of long-duration effort or effort that causes trauma to muscle tissue, the drink must be taken again before sleeping.
Thanks to its anti-catabolic properties, leucine is not only reserved for athletes and bodybuilders but is suitable for all sports players in general - and even senior citizens, who wish to best preserve their muscle mass and counter the effects of sarcopenia related to ageing or malnutrition.
Tryptophane, an amino acid of plant origin essential for athletes
Although tryptophane is the least abundant amino acid in the body, it is nonetheless essential because we cannot synthesise it.
Tryptophane is the metabolic precursor of serotonin, meaning that it is used in the synthesis of this hormone, which causes a good mood and regulates the appetite. Thus, tryptophane acts indirectly on our well-being and on the regulation of consumption of carbohydrates. This is very important for bodybuilders during periods of calorific restriction in fat reduction programmes, when hunger and mood variations may appear.
Did you know that tryptophane also improves endurance during athletic exertion? It enables more intense and longer effort, thus contributing to athletic performance.
Tryptophane acts as a natural antidepressant: it enables good mental energy and refreshing sleep. At the end of the day, it favours the synthesis of serotonin and melatonin, which causes calmness and sleep. This amino acid also helps athletes have a good emotional balance, essential to mental preparation before a competition.
In practical terms, athletes may choose to eat food that is rich in tryptophane such as:
- an afternoon snack consisting of bananas, dairy products, almonds or cashew nuts
- an evening meal including whole-grain rice and poultry
- a vegetarian meal including soya protein and dairy products.
- supplements rich in tryptophane, enabling better relaxation and preparation to more easily have refreshing sleep, essential for muscle anabolism and post-exertion recovery.
Leucine and tryptophane, two essential amino acids, therefore have a positive impact on sports performance.Leucine enables athletes longer and recover better after training or a competition.Tryptophane contributes to the well-being of athletes and improves their endurance during physical exertion.
- Pasiakos SM, McClung HL, McClung JP et al. Leucine-enriched essential amino acid supplementation during moderate steady state exercise enhances post-exercise muscle protein synthesis. Am J Clin Nutr. 2011 Sep;94(3):809-18.
- Buse, M. G., & Reid, S. S. (1975). Leucine. A possible regulator of protein turnover in muscle. Journal of Clinical Investigation, 56(5), 1250.
- Koopman, R., Wagenmakers, A. J., Manders, R. J., Zorenc, A. H., Senden, J. M., Gorselink, M., ... & van Loon, L. J. (2005). Combined ingestion of protein and free leucine with carbohydrate increases postexercise muscle protein synthesis in vivo in male subjects. American Journal of Physiology-Endocrinology and Metabolism, 288(4), E645-E653.
- Leucine content of foods, http://dietgrail.com/teneur-en-leucine-des-aliments/
- Fernstrom, J. D., & Wurtman, R. J. (1971). Brain serotonin content: physiological dependence on plasma tryptophan levels. Science, 173(3992), 149-152.Fernstrom, J. D., & Wurtman, R. J. (1971). Brain serotonin content: physiological dependence on plasma tryptophan levels. Science, 173(3992), 149-152.
- Amino-acid frequency, TIEM, http://www.tiem.utk.edu/~gross/bioed/webmodules/aminoacid.htm