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We often talk about proteins in the world of sports, nutrition and health. But do we really know what they are? Essential for the proper functioning of the body, they play a crucial role in building, repairing and maintaining human body tissues. And contrary to popular belief, they are not only for bodybuilders.
Definition: The building blocks of life
Proteins are large molecules made up of amino acids, linked together in long chains. There are 20 different amino acids, 9 of which are considered essential because the body cannot produce them. These must therefore be supplied through diet or food supplements.
The role of proteins extends far beyond muscle:
- They participate in the synthesis of enzymes, hormones, neurotransmitters.
- They ensure tissue repair, especially after physical exertion.
- They are involved in immune function and oxygen transport (via hemoglobin).
- They also play a role in the structure of skin, nails, and hair.
Protein requirements
Daily requirements vary according to age, physical activity, and health status. For a sedentary adult, recommendations are around 0.8 g of protein per kg of body weight. For athletes or elderly people, these requirements can go up to 1.6 or even 2 g/kg/day.
Protein sources are divided between animal proteins (meat, eggs, fish, dairy products) and plant-based proteins (legumes, cereals, tofu, oilseeds). Animal proteins generally have a complete profile of essential amino acids, but good plant-based complementarity also allows for excellent balance.
Proteins and physical activity
During exertion, muscle fibers undergo micro-tears. It is during the recovery phase that the body uses amino acids to repair and strengthen these fibers, a phenomenon known as muscle anabolism.
Consuming protein around training helps to:
- reduce muscle breakdown (catabolism)
- stimulate protein synthesis
- promote recovery and muscle development
This is why protein powder shakes, such as whey, are popular: easy to digest, rich in essential amino acids (especially leucine), and quickly absorbed.
Protein powders, useful but not essential
Protein powders are food supplements, not meal replacements. They are primarily for those who struggle to meet their needs solely through diet, such as athletes with high training frequency, vegetarians or vegans (under certain conditions), and seniors to prevent age-related muscle loss.
There are several types, including whey (whey protein), which is absorbed very quickly, casein, which is slower and ideal as a snack or in the evening, egg protein, and plant-based proteins, often derived from peas, rice, or hemp.
The important thing is to prioritize a balanced diet, with a good distribution of protein intake throughout the day.
The final word
Proteins are essential for the proper functioning of the human body. They are not only used to build muscle, but also participate in many vital functions: immunity, hormones, cell repair, digestion, etc. A varied diet, with a good balance between animal and plant proteins, meets daily needs. Supplements can be useful, but they never replace solid food.
Scientific references
Wolfe RR, “The underappreciated role of muscle in health and disease,” Am J Clin Nutr., 2006. https://pubmed.ncbi.nlm.nih.gov/16895805/
Phillips SM, “A brief review of critical processes in exercise-induced muscular hypertrophy,” Sports Med., 2014. https://pubmed.ncbi.nlm.nih.gov/25257866/
Bauer J. et al., “Evidence-based recommendations for optimal dietary protein intake in older people,” J Am Med Dir Assoc., 2013. https://pubmed.ncbi.nlm.nih.gov/23317514/
Tipton KD & Wolfe RR, “Protein and amino acids for athletes,” J Sports Sci., 2004. https://pubmed.ncbi.nlm.nih.gov/14971434/
