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Protein for sports: which one to choose and how to use it properly?

Are sports proteins only for bodybuilders? The answer is no. Whether you're running miles, cycling on the road, or lifting weights, your muscles need protein to recover, rebuild, and progress. But beware: between whey, casein, isolate, and plant-based alternatives, the choice should never be left to chance!

 

Why is protein essential for sports?

According to a scientific review published in the Journal of Sports Sciences, proteins play a key role in muscle repair, training adaptations, and post-exercise recovery.

The role of proteins in muscle development

During training, your muscles undergo significant stress which can cause micro-injuries. The body then uses amino acids from proteins to rebuild and strengthen damaged fibers. It is this repair process, repeated session after session, that gradually contributes to training adaptations and the development of muscle mass.

Proteins and post-exercise recovery

In addition to repairing damaged fibers, post-exercise protein intake is essential to stimulate the synthesis of new muscle proteins and help limit pain and soreness induced by exercise. It thus promotes more effective recovery and helps you string together sessions more easily, especially when training is frequent or intense.

Proteins, performance, and injury prevention

Proteins are also involved in the renewal of tendons, ligaments, and connective tissues. Sufficient intake supports the strength of these structures and can reduce the risk of injuries related to a high training load.

They also participate in the production of enzymes and hormones involved in energy metabolism, which can generally influence your performance.

Key takeaway: after training, muscle protein synthesis remains stimulated for many hours, and this effect can last up to 48 hours depending on the context (Oikawa et al., 2024).

 

What are the protein needs for athletes?

According to the joint position of the ACSM and the Academy of Nutrition and Dietetics, the protein needs of athletes are generally between 1.2 and 2.0 g/kg of body weight per day (Thomas et al., 2016). These intakes must be adapted according to the sport discipline, training volume, and practice level...

Protein for endurance sports

If you practice running, cycling, or triathlon, recent data suggest an intake generally between 1.5 and 1.8 g/kg of body weight per day, which can reach or exceed 2.0 g/kg/day during intensive periods or energy restriction.

Protein for bodybuilding and strength sports

You can aim for a higher range of 1.6 to 2.2 g/kg/day if you do bodybuilding, weightlifting, or CrossFit (Morton et al., 2018).

During periods of caloric restriction, higher intakes may be considered for healthy athletes to limit the loss of lean mass.

Proteins for beginner vs. experienced athletes

Beginner athletes generally tolerate moderate intakes because their margin for progress is significant. Conversely, experienced practitioners may need a more precise nutritional strategy (distribution of intake, choice of sources, practical timing), as adaptations become more difficult to achieve.

Practical guidelines:

  • Endurance sports: 1.2 to 1.8 g/kg/day
  • Bodybuilding / strength: 1.6 to 2.2 g/kg/day
  • Intense caloric restriction: 2.4 to >3 g/kg/day

 

What are the best protein sources for sports?

Each type of sports protein has its specificities. Here's a simple guide to navigate them:

Animal proteins: whey, casein, eggs, meat

Whey, (whey protein) is one of the most used in sports nutrition. It is rich in leucine, an essential amino acid involved in triggering muscle protein synthesis.

Casein, which is slower to digest, can be useful when your goal is to spread consumption over several hours (for example, before bed). It is the slow protein derived from milk.

Eggs are a classic reference in protein nutrition. Lean meats (chicken, turkey, lean beef) also provide complete proteins and are also rich in important micronutrients such as iron and zinc.

Plant proteins: peas, rice, soy, hemp

Long considered inferior, sources like peas, rice, or hemp actually have limiting amino acids when isolated (e.g., lysine deficiency for rice, methionine for peas).

However, the DIAAS score now validates the complementarity strategy: their combination allows for a more balanced overall intake (especially the pea-rice blend) to obtain a complete amino acid profile, biologically comparable to whey. Soy stands out as the major exception, naturally offering high bioavailability and a complete profile without the need for blending.

Native proteins or isolate: what are they?

Whey is the reference in sports nutrition due to its high content of Leucine, the "trigger" amino acid for the mTOR metabolic pathway. However, its effectiveness depends on the degree of processing:

  • Whey concentrate: contains about 70-80% protein. It retains bioactive fractions (immunoglobulins), but contains more lactose and lipids.
  • Whey isolate: obtained by microfiltration, it reaches more than 90% purity. Almost free of lactose, it offers superior absorption kinetics and optimal digestibility (Czarniecka-Skubina et al., 2025).
  • Whey hydrolysate: protein chains are pre-digested into peptides. This is the fastest form, causing a marked insulin peak, useful for glycogen resynthesis and immediate post-exercise MPS.

Unlike whey, micellar casein coagulates in the stomach, slowing gastric emptying. It releases amino acids constantly for 7 to 8 hours. Its role is primarily anti-catabolic, limiting muscle protein breakdown during prolonged fasting periods.

Protein supplements: useful or indispensable?

Protein supplements are not indispensable if your diet covers your needs. Their main interest is practical: ease of dosing, speed, transport... Consider them as a nutritional adjustment tool rather than a dietary staple.

 

Which protein to choose based on your sports goal?

For the athlete, protein is not just a macronutrient; it is a modulator of Muscle Protein Synthesis (MPS). The choice of a protein source must be based on two physiological pillars: absorption kinetics (the speed at which amino acids reach the bloodstream) and protein quality, measured today by the DIAAS score (Digestible Indispensable Amino Acid Score), which evaluates the digestibility of essential amino acids in the small intestine.

Protein for muscle gain

The goal is to maintain a positive nitrogen balance. Whey is the preferred tool here to saturate muscle receptors after exercise. A randomized study demonstrated that consistent whey supplementation over 4 weeks resulted in significantly greater lean mass gain compared to the control group (Kim et al., 2023).

  • Tip: aim for 1.6g to 2.2g of protein per kg of body weight.
  • Hint: Combine with casein in the evening to maintain amino acid intake overnight.

Protein for recovery

After exercise-induced muscle damage, whey facilitates fiber repair. Davies et al. (2018) showed, through a meta-analysis of 13 clinical trials, that whey protein restores contractile function more quickly, reducing soreness and loss of strength between 24h and 96h post-exercise.

Protein for fat loss

In caloric deficit, the risk of proteolysis (muscle wasting) increases. Whey isolate is preferred for its unbeatable protein/calorie ratio. Furthermore, the thermic effect of proteins is the highest of all macronutrients, promoting increased energy expenditure during digestion.

Protein for endurance

In endurance, a moderate dose of any protein, combined with carbohydrates, can optimize recovery after sessions.

 

When and how to consume protein for sports?

Protein before sport: good or bad idea?

Consuming protein 1 to 2 hours pre-workout can increase amino acid availability during exercise. However, avoid large portions that would slow digestion. A light snack containing 15 to 20 g of protein may be sufficient if you train on an empty stomach or several hours after your last meal.

Protein after sport: optimal timing

The post-exercise anabolic window generally extends up to 48 hours, with a peak sensitivity in the first 4 to 5 hours (Ji et al., 2025). Hence the importance of ingesting a protein source after exercise. Post-exercise hydration also remains essential.

Distribution of protein throughout the day

Distribute your protein intake over 3 to 5 meals to maintain a steady flow of amino acids. Aim for 0.25 to 0.40 g/kg per serving, or about 20 to 40 g per meal for an average adult.

Recommended dosage and mistakes to avoid

Some studies suggest that a protein intake of ~3 g/kg/day can be tolerated without adverse effects in healthy athletes. However, daily excess provides no additional benefits.

Don't forget to include proteins from food in your calculations: 100g of chicken provides about 30g of protein.

 

Protein for sport: real benefits and common misconceptions

The proven benefits of proteins for athletes

Studies confirm that proteins accelerate recovery, increase lean mass, reduce exercise-induced damage, and improve body composition. They can also support the immune system in certain contexts and contribute to bone health indirectly.

The most frequent misconceptions

According to the International Society of Sports Nutrition (ISSN), proteins do not damage kidneys in healthy individuals, contrary to popular belief.

They also do not automatically cause weight gain: it is the overall caloric surplus that determines weight gain.

Women do not have to fear excessive muscle development by consuming enough dietary protein. Hypertrophy depends on training and hormonal status.

Excess protein: are there risks?

In healthy individuals, studies report that high protein intakes, up to about 2.2 to 3.0 g/kg/day, are not associated with deleterious effects on renal function in the short or medium term. However, excessive consumption can cause digestive problems and requires increased hydration. Individuals with pre-existing kidney conditions should consult a healthcare professional.

 

How to choose your sports protein well?

Reading a protein label

Check the protein content per serving (minimum 20 g), the amino acid profile (presence of all 9 essential amino acids), and the ingredients list. Compare the value for money by calculating the cost per gram.

Ingredient quality and origin

Scientific data does not show systematic nutritional superiority of proteins from grass-fed animals compared to others. However, third-party certifications help ensure product quality and safety.

Protein with or without additives

Additives (sweeteners, flavorings, lecithin) are considered safe at authorized doses. Their role is primarily technical (taste, texture, solubility), not nutritional. However, be wary of products containing numerous additives, artificial sweeteners, or fillers.

Organic, native, or classic proteins

Native proteins better retain their original molecular structure and potentially offer better bioavailability. The organic label guarantees the absence of pesticides and antibiotics.

 

FAQ: Protein for sports

What is the best protein for sports?

Whey remains the benchmark for its rapid absorption and optimal leucine composition. However, plant-based pea-rice blends now rival its effectiveness. Choose according to your goals: whey for speed, casein for nighttime, plant-based for personal convictions.

Should I take protein every day?

Yes, if your dietary intake does not meet your daily needs. Rest days also require protein for continuous recovery. Simply adjust quantities to your daily energy expenditure. 

Plant-based or animal protein: which to choose?

Animal proteins are more complete and offer better digestibility. Plant-based proteins, when intelligently combined, can match their effectiveness while providing fiber and antioxidants. Your choice may reflect your ethical values or dietary constraints.

Can I take protein without doing strength training?

Yes, if you consume dietary proteins (0.8 g/kg/day). However, powdered supplements are not essential in this context.

From what age can one consume sports proteins?

In adolescents, needs can be high due to growth and sports activity. However, prioritize protein-rich foods as the primary source: supplements should remain secondary. When in doubt, it is best to consult a nutritionist.

 

What to remember

Sports protein is an essential pillar of your nutrition, regardless of your discipline. Remember these key points: aim for 1.2 to 2.2 g/kg depending on your activity, spread consumption throughout the day, prioritize quality sources, and consume 20 to 40 g within hours of exercise. Combine protein and optimal hydration to maximize your performance. Personalization remains paramount: adapt these recommendations to your profile, your goals, and your feelings.

 

Bibliography

Phillips, S. M., & Van Loon, L. J. (2011). Dietary protein for athletes: from requirements to optimum adaptation. Journal of sports sciences, 29 Suppl 1, S29–S38. https://doi.org/10.1080/02640414.2011.619204

Witard, O. C., Hearris, M., & Morgan, P. T. (2025). Protein Nutrition for Endurance Athletes: A Metabolic Focus on Promoting Recovery and Training Adaptation. Sports medicine (Auckland, N.Z.), 55(6), 1361–1376. https://doi.org/10.1007/s40279-025-02203-8

Govindasamy, K., Parpa, K., Katanic, B., Clark, C. C. T., Elayaraja, M., Kambitta Valappil, I. N., Dulceanu, C., Geantă, V. A., Tolan, G. A., & Zouhal, H. (2025). Effect of Plant-Based Proteins on Recovery from Resistance Exercise-Induced Muscle Damage in Healthy Young Adults-A Systematic Review. Nutrients, 17(15), 2571. https://doi.org/10.3390/nu17152571

Antonio, J., Evans, C., Ferrando, A. A., Stout, J. R., Antonio, B., Cinteo, H., Harty, P., Arent, S. M., Candow, D. G., Forbes, S. C., Kerksick, C. M., Pereira, F., Gonzalez, D., & Kreider, R. B. (2024). Common questions and misconceptions about protein supplementation: what does the scientific evidence really show?. Journal of the International Society of Sports Nutrition, 21(1), 2341903. https://doi.org/10.1080/15502783.2024.2341903

Davies, R. W., Lynch, A. E., Kumar, U., & Jakeman, P. M. (2024). Characterisation of the Muscle Protein Synthetic Response to Resistance Exercise in Healthy Adults: A Systematic Review and Exploratory Meta-Analysis. Translational sports medicine, 2024, 3184356. https://doi.org/10.1155/2024/3184356

Thomas, D. T., Erdman, K. A., & Burke, L. M. (2016). Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance. Journal of the Academy of Nutrition and Dietetics, 116(3), 501–528. https://doi.org/10.1016/j.jand.2015.12.006

Morton, R. W., Murphy, K. T., McKellar, S. R., Schoenfeld, B. J., Henselmans, M., Helms, E., Aragon, A. A., Devries, M. C., Banfield, L., Krieger, J. W., & Phillips, S. M. (2018). A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. British journal of sports medicine, 52(6), 376–384. https://doi.org/10.1136/bjsports-2017-097608

Czarniecka-Skubina, E., Pielak, M., Neffe-Skocińska, K., Kajak-Siemaszko, K., Karp-Paździerska, S., Głuchowski, A., Moczkowska-Wyrwisz, M., Rosiak, E., Rutkowska, J., Antoniewska-Krzeska, A., & Zielińska, D. (2025). Whey-A Valuable Technological Resource for the Production of New Functional Products with Added Health-Promoting Properties. Foods (Basel, Switzerland), 14(24), 4258. https://doi.org/10.3390/foods14244258

Kim, C. B., Park, J. H., Park, H. S., Kim, H. J., & Park, J. J. (2023). Effects of Whey Protein Supplement on 4-Week Resistance Exercise-Induced Improvements in Muscle Mass and Isokinetic Muscular Function under Dietary Control. Nutrients, 15(4), 1003. https://doi.org/10.3390/nu15041003

Davies, R. W., Carson, B. P., & Jakeman, P. M. (2018). The Effect of Whey Protein Supplementation on the Temporal Recovery of Muscle Function Following Resistance Training: A Systematic Review and Meta-Analysis. Nutrients, 10(2), 221. https://doi.org/10.3390/nu10020221

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