Protein and endurance: a winning duo or a false good idea?
Endurance and protein: key role in recovery, performance, and muscle preservation. Tips, timing, and sources for healthy eating.
Table of Contents
Introduction: Endurance and protein, an underestimated alliance
In the world of sports nutrition, the question of the link between protein intake and performance in endurance sports often sparks debate. Many instinctively associate proteins with strength sports or mass gain, sometimes forgetting their fundamental role for endurance athletes. However, the nutritional needs of runners, cyclists or triathlon enthusiasts go far beyond energy management alone. To progress, perform and above all last, you have to think about tissue repair, muscle mass preservation and recovery. Let's discover together how proteins fit into the routine of endurance athletes and whether this duo represents a real performance lever.
Endurance: what are the specific nutritional needs?
Endurance sports like running, cycling, or swimming put a lot of strain on the body over a long period of time, sometimes lasting several hours. To sustain this effort, relying solely on carbohydrates isn't enough:
-Muscle fibers suffer repeated micro-lesions with each impact or prolonged contraction.
-Energy reserves must be replenished quickly in order to maintain performance from one session to the next.
In practice, an endurance athlete must pay attention to three pillars:
- Maintain a stable body weight that is appropriate for your discipline.
- Preserve your muscle mass to limit fatigue and prevent injuries.
- Optimize recovery between workouts to progress without overexertion.
This is where protein consumption comes into play: beyond their role in mass gain, proteins are essential for tissue repair and muscle adaptation to exercise.
What is the role of protein in endurance athletes?
Muscle proteins are the building blocks of all contractile tissues. During prolonged exercise, accumulated microtraumas require continuous regeneration.
Protein synthesis allows:
-To repair damaged muscle fibers,
-To adapt the musculature to the specific constraints of endurance,
-To support targeted muscle development during strengthening sessions, essential for sustainable practice.
Far from being reserved for strength sports, proteins promote:
-Limiting uncontrolled weight loss (i.e. unwanted muscle wasting),
-Maintaining good overall health,
-More effective recovery, especially when doing consecutive sessions.
Impulse Nutrition Tip: Consider splitting your protein intake throughout the day to maximize the availability of essential amino acids throughout the training and recovery cycle.
Animal vs. plant proteins: which should you choose?
Animal proteins
-Dairy products, eggs, lean meats and fish are considered complete sources, rich in essential amino acids and particularly branched-chain amino acids (leucine, isoleucine, valine), key for the synthesis of muscle proteins.
-Their bioavailability is optimal, which promotes rapid use by the body.
Plant proteins
-Plant proteins, such as lentils, peas, quinoa, soy, spirulina or chia seeds, offer an interesting diversity for varying your diet, supporting digestion and helping you achieve weight loss goals.
-However, most plant proteins are said to be incomplete, meaning they are deficient in one or more essential amino acids. To optimize their biological value, it is recommended to combine complementary plant sources, whose amino acid profiles complement each other. This is particularly the case for legume + cereal combinations (e.g., lentils + rice, chickpeas + semolina, or corn + kidney beans), which provide a complete amino acid profile, close to that of animal proteins.
| Source of protein | Protein/100g | Rich in essential amino acids | Specificities |
|---|---|---|---|
| Chicken | 25g | Excellent | Low in fat |
| Egg | 13g | Excellent | Natural source of BCAA |
| White cheese | 8g | Very good | Low in lactose depending on the type |
| Lentils | 9g | Average | Combine with cereals |
| Chickpeas | 8g | Average | Rich in fiber |
| Quinoa | 14g | Good | Contains all essential amino acids |
At Impulse Nutrition, the selection of ingredients is based on a dual requirement: favoring high-quality raw materials, carefully chosen for their effectiveness and their relevance to the specific needs of athletes, while guaranteeing maximum transparency on the compositions.
Timing of consumption: before, during or after exercise?
When to consume protein?
-Before the effort: Not very relevant, except for long or intense sessions requiring an intake of branched-chain amino acids to limit catabolism.
-During the effort: Reserved for very long-term efforts (ultra-trail, Ironman), in the form of specific drinks, combining carbohydrates and essential amino acids to maintain muscle integrity.
-After the effort: The key moment to optimize tissue repair and stimulate protein synthesis. A 30-60 minute post-exercise window is ideal to promote recovery.
A balanced distribution of protein intake throughout the day, combined with a strategic dose after each session, maximizes benefits without overloading the body.
Recommended quantity according to the type of activity
Recommendations vary depending on the intensity, frequency and type of endurance sport practiced.
-Endurance athletes (running, cycling, swimming):
1.2 to 1.6 g of protein per kg of body weight per day.
Ex: a 70 kg athlete will aim for 85 to 110 g of protein per day.
-Endurance sports with regular muscle strengthening:
Rather 1.6 to 1.8 g/kg/day, to support muscle adaptation .
-Strength sports or mass gain period:
Sometimes up to 2.2 g/kg/day to stimulate muscle growth, but this is not the main goal for endurance.
Precautions:
-Adapt the intake according to body weight, training volume and expected recovery level.
-Integrate varied protein sources, both animal and vegetable, for complete coverage of essential amino acids.
Protein and Recovery: What Does the Science Say?
Numerous studies show that protein consumption after endurance exercise promotes muscle tissue repair, limits muscle soreness and accelerates the return to performance. [1], [2]
Branched-chain amino acids play a central role in protein synthesis, limiting the phenomenon of muscle breakdown (catabolism).
For an endurance athlete, it has been proven that the combination of proteins + carbohydrates after exercise [3]:
-Optimizes the recovery and replenishment of energy reserves,
-Supports tissue repair and maintenance of muscle mass,
-Reduces the feeling of fatigue during close sessions.
Impulse Nutrition's expertise is based on this data to formulate products that respect the purity of active ingredients and the accuracy of dosages, with total traceability and scientifically validated effectiveness.
The risks of too much or too little protein
Too little protein:
-Risk of loss of muscle mass,
-Slowing down of tissue repair,
-Increased fatigue and risk of injury,
-Decreased performance and incomplete recovery.
Too much protein:
-Renal overload for people at risk,
-Storage in the form of fat if the excess is chronic,
-Dietary imbalance, especially if protein sources are not varied.
It is therefore essential to adjust the quantity of protein to one's real needs, favoring quality rather than simple quantity, and respecting the diversity of protein types.
Verdict: Are proteins essential allies for endurance athletes?
Modern sports nutrition fully recognizes the importance of protein intake for all athletes, including endurance sports practitioners.
-They are not only used for mass gain,
-They are essential for tissue repair, maintaining muscle mass and recovery.
An endurance athlete has every interest in:
-Vary your protein sources (animal and vegetable) to benefit from all the essential amino acids,
-Adapt your intake to your body weight and the specific nature of your discipline,
-Favor products designed from high-quality active ingredients carefully chosen for their effectiveness and relevance to the specific needs of athletes, reflecting the Impulse Nutrition commitment.
SOURCES
[ 1] Witard OC, Hearris M., Morgan PT “ Protein Nutrition for Endurance Athletes: A Metabolic Focus on Promoting Recovery and Training Adaptation ”. Sports Med. [ Online ]. June 1, 2025. Vol. 55, n°6, p. 1361 - 1376. Available on : < https://doi.org/10.1007/s40279-025-02203-8 >
[ 2] Cintineo HP et al. “ Effects of Protein Supplementation on Performance and Recovery in Resistance and Endurance Training ”. Forehead. Nutr . [ Online ]. September 11, 2018. Vol. 5, p. 83. Available on : < https://doi.org/10.3389/fnut.2018.00083 >
[ 3] Kerksick C. et al. " International Society of Sports Nutrition position stand: Nutrient timing ." J. Int. Soc. Sports Nutr . [Online ] . October 3, 2008. Vol. 5, p. 17. Available at : < https://doi.org/10.1186/1550-2783-5-17 >
