During prolonged and/or intense exercise, amino acids, which are part of our muscles’ makeup, are used up to supply the energy necessary for the effort we are generating. Even if the use of these amino acids is minimal in terms of quantity, it has a significant impact on our muscles function. After exercising, our organism automatically goes into a muscle protein rebuilding phase (called ‘anabolism’) the effectiveness of which largely depends on the availability of amino acids and of different hormonal signals, including insulin. Your protein intake after exercising will therefore boost muscle reconstruction.
Which are the best proteins to improve your muscle mass? There exist two different sources: amino acids, which are the precursors to proteins, and whole proteins which are made of assembled amino acids, and come from a variety of sources. The idea is to combine both sources as wisely as possible. It is important that you favor the use of proteins which have high biological value, such as animal protein (especially eggs, fish, milk and dairy products), whose nutritional value is generally higher than that of plant protein, as they have a better balance of essential amino acids, with higher concentrations of leucine, and are easier to digest.
Proteins are not all digested at the same rate. Ideally, the snack you take after your training sessions should contain both fast-digested and slower-digested proteins. The former are rapidly digested and absorbed, and immediately supply the organism with amino acids for about the next three hours. The latter are digested and absorbed more gradually, and begin supplying amino acids two hours after having been ingested, and for the next six hours. Slow protein therefore continues the work begun by the faster kind, and promotes muscle anabolism for a longer period of time.
Milk naturally contains a mix of fast protein (20% whey) and slow protein (80% casein), which makes it a very good protein source for recovery.
What amount of protein should you consume?
Recommended intake is generally somewhere between 1.2 and 1.5 g for every kilogram of bodyweight daily; and up to 2 g if you wish to increase muscle mass quickly. We need to ensure at least two thirds of our protein intake comes from our diet, and the rest from supplements with high biological value.
When should you consume protein?
The optimal intake period is during the early recovery phase (that is, immediately after exercising) when muscle anabolism is highest and requires high amino acid availability. It is recommended that you take 10 to 20 g within the first thirty minutes after exercising. For example, during the stretching which is usually done for five to ten minutes after exercising. In the case of prolonged and very significant effort, protein metabolism may be affected by the increased use of amino acids as an energy source. In this case, it is recommended that you take a special type of amino acid while exercising: branched-chain amino acids (leucine, isoleucine, valine), as they reduce muscle protein degradation, delay muscle glycogen depletion (our muscles’ sugar supply), and may help diminish central nervous system fatigue.