Protein and the Athlete, by Susan Kitchen RD, CSSD

It’s true that athletes require more protein than their sedentary counterparts. And while many athletes meet or exceed the recommended daily protein requirement, they may not be distributing their protein intake appropriately. Consuming too much protein can be as risky as not having enough. Excess protein increases the production of ammonia (as a waste product), which the body eliminates via urine and sweat. As a result, ridding the body of ammonia requires adequate hydration to process the waste. Alternatively, inadequate protein intake can negatively affect the formation of hormones and enzymes, and hinder muscle recovery/repair post workout.

Protein serves many important roles:

  • Supports the growth and repair of muscles, tendons, ligaments, skin, hair and nails
  • Assists in the formation of hormones, enzymes, and neurotransmitters
  • Creates antibodies, which are a key component of the immune system
  • Needed for the formation of hemoglobin (the substance that carries oxygen to the muscles)
  • Serves as a fuel source during endurance training when carbohydrate reserves run low
  • Helps maintain water balance in the body

How much protein does an athlete need?

The body can only metabolize 20-40g at one time so loading your plate or smoothie with excess protein will not yield the desired goal. Consequently, an abundance of any macro-nutrient (carbs, protein and fat) will be stored as fat in the adipose tissue. The athlete’s size and age are determining factors in how much to consume at one time. Smaller athletes may need only 15-20g whereas larger athletes with more muscle mass and higher energy output can easily incorporate up to 35-40g protein at one meal. Older athletes (>55-60 years old) require more protein to achieve the same effect due to the progressive loss of muscle mass associated with the aging process.
Athlete’s daily protein requirement: 1.4-1.7g/kg/day or 0.6-0.9/lb/day.
Post workout protein requirement: 0.25-0.3g/kg within 30 min.

For example, a 150 lb athlete would need 90-135g/day and 17-20g protein post workout (along with simple carbs to replenish glycogen stores and fuel muscle synthesis).

Timing of protein

To maximize physical adaptation, maintain a strong immune system, and maximize recovery, both the timing and amount of protein are critical.

– Begin and end your day with 15-20 g protein to suppress the negative effect of hormonal stress (cortisol) that is often elevated during a heavy training phase or when suffering from broken sleep.

– Meals – include protein at each meal (15-40g depending on size and age of athlete).

– Snacks – bridge the gap between meals that are more than four hours apart. Include protein in snacks (10-15g).

– Bedtime snack – dairy protein (made up of whey and casein) is ideal due to casein, which is slow releasing (whey is fast releasing) and helps stabilize blood sugars as well as offsets muscle breakdown during the overnight fast.

Intense and prolonged training sessions breakdown muscle tissue, followed by an increase in muscle protein synthesis over the next 24 hours. Consuming high-quality protein within 30 min post workout enhances this process and reduces the cortisol response caused by the stress of the training session. When fuel stores (glycogen) run low, the body burns protein as fuel by breaking down muscle. Failing to fuel with carbohydrates during a key workout (intense or long in duration (>75 min)) will lead to unnecessary muscle breakdown. This defeats the purpose of the workout and ultimately jeopardizes the athlete’s health and metabolic system.

Protein Sources

Proteins are made up of amino acids (AAs), which are the building blocks to muscles, tendons, ligaments, skin, hair, and nails. AA that are manufactured by our body (from the breakdown of muscle tissue) are considered nonessential to our diet. However, AA that we cannot manufacture in our body are considered essential to our diet and must be consumed in adequate amounts for optimal performance and overall health.

Animal sources are considered a complete protein because they contain all nine essential AAs necessary for protein synthesis. Some plant-based proteins are incomplete proteins, because they do not contain all of the nine essential AAs. However, some plant-based proteins such as Pumpkin Seed, Peanut Flour, or Sunflower do contain the essential AAs.

Both animal and plant protein sources will meet overall protein needs as long as consumption is from a variety of sources, particularly when relying on plant-based options.

Protein sources and recommended servings:

Lean meat, fish, poultry or soy-based foods (tofu, tempeh) – 2-4/day
Eggs – great choice for breakfast and on salads
Dairy products (milk, yogurt, cheese) – 2-3/day
Legumes (4-5/week)

Animal Sources:

Cottage cheese ½ cup – 13g
Greek yogurt 5oz – 11-20g
Milk 8oz – 8g
Cheese 1oz – 4-7gBeef, chicken, fish 1oz – 7-8g
Eggs 1 – 6g
Ground turkey 1oz – 7g
Cocoa Elite Recovery/serving – 12g
Cocoa Elite Everyday Whey protein/serving – 22g

Plant-based sources:

Tofu ½ cup – 8g
Tempeh 3oz – 15g
Spirulina (seaweed) 2 tbsp – 8g
Lentils ½ cup – 9g
Nuts 1oz – 4-6g
Nut butter 2 tbsp – 8g
Edamame ½ cup – 8g
Cocoa Elite Vegan recovery/serving 10g-11g


Susan Kitchen has a Master’s in Public Health and Nutrition. She is a registered and licensed dietitian, a certified sports dietitian, a USA Triathlon Level II endurance coach, an IRONMAN Certified Coach and on the United States Olympic Committee sports dietitian registry.




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