Protein for Athletes: How Much Do You Really Need?

Protein for athletes is not a one-size-fits-all recommendation. The right protein target depends critically on your sport type, training volume, body composition goals, and whether you are in a competitive or off-season phase. This guide translates the latest ACSM and ISSN position statements into practical, sport-specific protein targets for endurance athletes, strength and power athletes, and team sport competitors.

By the FitCalcHub Editorial Team — Updated July 2026 — 10 min read

Does Training Type Change Protein Requirements?

Yes — significantly. The standard RDA of 0.8 g/kg was not designed with athletes in mind. It represents the minimum intake to prevent deficiency in sedentary adults. The American College of Sports Medicine (ACSM), the Academy of Nutrition and Dietetics, and Dietitians of Canada jointly recommend 1.2–2.0 g/kg per day for physically active adults, with the upper range applying to those focused on muscle gain or training in a calorie deficit.

The International Society of Sports Nutrition (ISSN) position stand goes further, recommending 1.4–2.0 g/kg for general athletic populations and up to 2.3–3.1 g/kg during aggressive cutting phases for lean, resistance-trained athletes. The appropriate protein intake for athletes therefore ranges across a wide spectrum depending on training demands.

Use the Protein Intake Calculator to find your personalised protein target based on your current body weight, training type, and goal.

Protein for Endurance Athletes

Endurance athletes — marathon runners, cyclists, triathletes, swimmers — have protein requirements that are often underestimated because endurance sports are not primarily associated with muscle building. However, protein for athletes in endurance disciplines serves several critical functions:

  • Muscle repair: High training volumes cause significant muscle protein breakdown, particularly during long sessions exceeding 90 minutes.
  • Fuel contribution: During prolonged exercise when glycogen stores become depleted, amino acids can contribute up to 5–10% of total energy expenditure.
  • Immune function support: Heavy endurance training suppresses immune function, and adequate protein supports immune cell production and repair.

The ACSM recommends endurance athletes consume 1.2–1.4 g/kg per day as a baseline, with increases to 1.6 g/kg during particularly high-volume training blocks or when running a calorie deficit. For a 65 kg female marathon runner, this means 78–104 g of protein per day.

Based on: Thomas DT, Erdman KA, Burke LM. "Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance." J Acad Nutr Diet. 2016;116(3):501–528. PubMed ↗

Protein for Strength and Power Athletes

Strength athletes — weightlifters, powerlifters, bodybuilders — have the highest protein requirements of any athletic population because the primary training stimulus (progressive resistance overload) directly drives muscle protein synthesis. Higher training volume means more protein is needed to support the repair and hypertrophy response.

The ISSN recommends 1.6–2.2 g/kg per day for strength athletes in a calorie surplus and up to 2.3–3.1 g/kg during cutting phases to preserve lean mass under an aggressive deficit. For an 85 kg male powerlifter targeting muscle gain, this means 136–187 g of protein per day at 1.6–2.2 g/kg.

Based on: Jäger R, Kerksick CM, Campbell BI, et al. "International Society of Sports Nutrition Position Stand: protein and exercise." J Int Soc Sports Nutr. 2017;14:20. PubMed ↗

Protein Requirements by Sport Type: Summary Table

Sport type Recommended intake Source
Endurance (running, cycling, swimming) 1.2–1.6 g/kg ACSM 2016
Team sports (football, basketball, hockey) 1.4–1.8 g/kg ACSM 2016
Strength & power (weightlifting, powerlifting) 1.6–2.2 g/kg ISSN 2017
Bodybuilding / physique (bulking) 1.6–2.2 g/kg ISSN 2017
Bodybuilding / physique (cutting) 2.3–3.1 g/kg ISSN 2017

Protein Timing for Athletic Performance

For athletes who train regularly, the distribution of protein across the day matters in addition to total daily intake. Research supports consuming protein within 2–4 hours of resistance training to maximise the anabolic response. Practically, this means having a protein-containing meal or snack shortly after each training session.

The recommended per-meal threshold for athletes is 0.4 g/kg per feeding, distributed across 3–5 meals. This provides the leucine bolus needed to maximally stimulate muscle protein synthesis at each feeding event without diminishing returns from very large single doses.

For a comprehensive guide to applying protein for muscle growth, including how protein interacts with calorie surplus and training programme design, see our guide to Protein for Muscle Gain.

Common Protein Mistakes Athletes Make

Despite higher protein needs, several common errors prevent athletes from optimising their intake:

  • Underestimating needs during cardio-heavy training: Endurance athletes often assume they only need carbohydrates. Protein intake below 1.2 g/kg during high-volume running or cycling training accelerates muscle breakdown and impairs recovery.
  • Clustering protein at one meal: Eating most daily protein at dinner reduces the number of anabolic stimuli across the day. Spreading protein evenly across meals maximises MPS.
  • Ignoring protein during calorie restriction: Athletes who cut calories to make weight often reduce protein simultaneously. Maintaining or increasing protein per kg during a calorie deficit is critical for preserving lean mass.
  • Relying solely on supplements: Protein powder is a convenient supplement but should complement — not replace — whole food protein sources, which provide additional micronutrients essential for athletic performance.

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Frequently Asked Questions

How much protein do athletes need per day?

Protein for athletes ranges from 1.2 g/kg for endurance athletes to 2.2+ g/kg for strength athletes during cutting phases. The ACSM recommends 1.2–2.0 g/kg for physically active adults, while the ISSN supports up to 2.3–3.1 g/kg for lean resistance-trained athletes in aggressive calorie deficits. Use the Protein Intake Calculator to find your sport-specific target based on your weight and training type.

Do endurance athletes need less protein than strength athletes?

Yes — endurance athletes generally need less protein than strength athletes, but they still need more than sedentary adults. The ACSM recommends 1.2–1.4 g/kg for endurance athletes versus 1.6–2.2 g/kg for strength athletes. Endurance athletes need protein primarily for muscle repair and immune support, while strength athletes need it primarily to drive muscle hypertrophy. Both groups significantly exceed the standard 0.8 g/kg RDA.

What is the ISSN recommendation for athlete protein intake?

The International Society of Sports Nutrition (ISSN) position stand recommends 1.4–2.0 g/kg per day for general athletic populations. For resistance-trained athletes focused on muscle gain, 1.6–2.2 g/kg is recommended. During aggressive calorie restriction (cutting phases) for lean, resistance-trained athletes, the ISSN supports intakes of 2.3–3.1 g/kg to maximise lean mass preservation — though this upper range is specific to competitive physique athletes and is not necessary for recreational gym-goers.

Should athletes eat protein before or after training?

Both before and after training are beneficial, but the window is wider than once thought. Current evidence suggests consuming protein within 2–4 hours either side of a training session is sufficient to maximise muscle protein synthesis. A practical approach: eat a protein-containing meal 1–2 hours before training and another within 2 hours after. The total daily protein intake matters more than exact timing, but distributing protein across meals around training is a worthwhile strategy for competitive athletes.

How much protein do team sport athletes need?

Team sport athletes — football, basketball, hockey, rugby — have combined endurance and strength demands, placing their protein needs between the two extremes. The ACSM recommends 1.4–1.8 g/kg per day for team sport athletes. During periods of heavy training or tournament schedules, moving toward 1.8–2.0 g/kg helps maintain lean mass and support recovery between sessions. Carbohydrate intake remains critical for team sport performance and should not be compromised to increase protein.

Can athletes get enough protein from food alone without supplements?

Yes — most athletes can meet their protein targets from whole food sources without supplements. A 75 kg athlete targeting 2.0 g/kg (150 g of protein per day) can achieve this from 4 meals containing roughly 35–40 g of protein each — achievable from chicken, fish, eggs, Greek yoghurt, legumes, and dairy. Protein powders are a convenient tool for hitting targets around training when whole foods are impractical, but they are not required for most athletes eating a varied diet.

Does protein quality matter for athletes?

Yes — protein quality matters for athletes, primarily because of leucine content and digestibility. Animal proteins (whey, chicken, eggs, fish) have higher leucine density and digestibility scores (DIAAS) than most plant proteins, making them more effective per gram at stimulating muscle protein synthesis. Athletes relying primarily on plant proteins should target the upper end of recommended ranges and include leucine-rich plant sources such as soy, pea protein, and lentils to compensate for lower per-gram effectiveness.

What happens if athletes eat too little protein?

Insufficient protein for athletes leads to impaired recovery, reduced muscle protein synthesis, accelerated muscle breakdown, and decreased performance over time. Chronically under-fuelling protein is associated with increased injury risk, immune suppression during heavy training periods, and slower adaptation to training. The consequences are most acute during calorie-restricted phases when the body is under additional metabolic stress — making high protein intake most critical precisely when total food intake is lower.

This article is part of our complete Nutrition Guide.

Medical Disclaimer: This article is for educational purposes only and is not intended as medical advice. Athletes with specific medical conditions, those competing at elite levels, or those with extreme training demands should consult a registered sports dietitian for personalised guidance.

Scientific References

  1. Thomas DT, Erdman KA, Burke LM. "Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance." J Acad Nutr Diet. 2016;116(3):501–528. PubMed ↗
  2. Jäger R, Kerksick CM, Campbell BI, et al. "International Society of Sports Nutrition Position Stand: protein and exercise." J Int Soc Sports Nutr. 2017;14:20. PubMed ↗
  3. Morton RW, Murphy KT, McKellar SR, et al. "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." Br J Sports Med. 2018;52(6):376–384. PubMed ↗