When it comes to endurance sports, we tend to focus only on the role and dosage of carbohydrates: being endurance sports, sugars are the essential macronutrient to ensure rapid energy to the muscle and body. The role of Protein in these sports is often underestimated, the opposite of what happens in Energy sports, in which athletes often have a vision that can be defined as "centric hypertrophy". Neither of these two approaches is the correct one: for an athlete it is good to give the correct importance to each macronutrient.

Proteins: what they are and why they are needed

Protein are macromolecules composed of amino acids and involved in countless functions in the human body, including structural, muscle building and support. Each protein differs according to its amino acid profile: our body is not able to synthesize all amino acids independently and for this reason it must necessarily take some of them through food, which are defined as essential (EAA). Among these, leucine, isoleucine and valine are particularly known in the sports world as branched amino acids (BCAAs) and are of real importance for combating muscle catabolism and for recovery.

Traditionally for endurance athletes, Protein and amino acids are considered less important than carbohydrates , but in reality the correct protein intake (in terms of quantity and quality) is essential not so much for increasing performance directly but above all for muscle efficiency and body composition . In addition, some sports, although considered "endurance", do not properly fall into the endurance category. In fact, a distinction must be made between LIEE or HIEE sports (Low or High Intensity Endurance Exercises): in these cases different metabolisms are activated. The aerobic oxidative one in case of low intensity exercises and the anaerobic one for high intensity exercises.

In the case of some endurance sports that also use strength and Energy, such as rugby or cross training, Protein are also essential for the prevention of tissue damage. The likelihood of muscle injury is also important for athletes who are used to training or very long competitions, because the lean mass risks being affected and run into catabolic states.

Protein requirement for the endurance athlete

Obviously, the achievement of protein requirements involves various benefits both for those who practice sports and for those who can consider themselves sedentary. This parameter is different for each individual and depends on various factors, including the physical activity practiced and biochemical individuality. Various scientific reference societies such as the American College of Sport Medicine and the most recent publications in the scientific literature (" NSCA's Guide to Sport and Exercise Nutrition ", 2011. Campbell & Spano. Human Kinetics) report ranges of values ​​useful for establishing the need protein based on the sport practiced.

Here are some of them:

  • SEDENTARY individuals : 0.7 - 0.9 g / kg body weight / day
  • Sportsman with an ACTIVE lifestyle : 1 g / kg of body weight / day
  • ENDURANCE sports: 4 g / kg of body weight / day
  • Tennis, fencing, sailing, climbing : 1.6 g / kg of body weight / day
  • TEAM Sports (acyclic) : 1.6 g / kg body weight / day

This translates in practical terms into a rather simple calculation. Considering for example a tennis athlete of about 70 kg and applying these ranges, the same athlete should consume at least 112g of protein per day to reach the protein requirement dictated by his sporting activity. It sounds pretty simple, but it's not always the case. Just think that out of 200g of chicken breast, just 46g of protein is eaten. Per high requirements or vegetarian or vegan diets it is therefore not so obvious to be able to reach the recommended daily protein quota.

Protein powders can be useful for this: they involve less digestive effort and allow you to easily add Protein even to snacks and snacks. There are also commercially available Protein derived from multiple sources: cow's milk, goat's milk, beef, salmon, eggs, peas, soy and legumes. The panorama is therefore quite wide, and allows everyone to find a valid alternative, even for intolerant and allergic people.

But what is the usefulness of Protein for the endurance athlete?

Among the many benefits borne by this macronutrient, we remind you that Protein allow those who practice endurance sports:

  • To use EAA as an energy source for the muscle during activity;
  • To exploit the same Protein for continuous muscle remodeling;
  • Support to the process of forming new capillary beds;
  • To optimize the mitochondria both in size and quantity, with a consequent increase in the production of mitochondrial enzymes;
  • To increase the amount of hemoglobin and the volume of the blood;
  • To perform HIEE with greater efficiency, and in the case of sports that also involve the use of strength and Energy to support muscle hypertrophy.

Despite the many positive effects of protein intake, many endurance athletes are still wary. The main question is often “but isn't eating protein bad for you?”.

The answer is as obvious as it is trivial: nothing is harmful when it does not exceed our needs . It is therefore good to stick to the quantities recommended by the guidelines or to rely on a professional, because although Protein do not hurt (and it has been proven that even the abuse of this nutrient is not harmful to the body) an excess in their consumption does NOT involve additional benefits.

The only case in which exceeding the consumption ranges recommended by the guidelines can guarantee benefits is when the athlete has to face periods of severe caloric restriction. In these cases, the RDA range for protein of 1.8 - 2.7g / kg body weight / day is also considered acceptable.


It is therefore certainly important for the endurance athlete to check that they are getting enough protein. Although the goal of these athletes is not hypertrophy, this macronutrient allows to maximize and optimize various biological processes in the body, not limited only to muscle growth. Especially for those who practice long-lasting sports, the recovery phase is supported when the protein needs are satisfied.


NSCA’s Guide to Sport and Exercise Nutrition”, 2011. Campbell & Spano. Human Kinetics

ACSM's Guidelines for Exercise Testing and Prescription (American College of Sports Medicine)

American Dietetic Association; Dietitians of Canada; American College of Sports Medicine, Rodriguez NR, Di Marco NM, Langley S. American College of Sports Medicine position stand. Nutrition and athletic performance. Med Sci Sports Exerc. 2009 Mar;41(3):709-31. doi: 10.1249/MSS.0b013e31890eb86. PMID: 19225360.

Jeukendrup AE. Nutrition for endurance sports: marathon, triathlon, and road cycling. J Sports Sci. 2011;29 Suppl 1:S91-9. doi: 10.1080/02640414.2011.610348. Epub 2011 Sep 15. PMID: 21916794.