Protein for performance: In-depth

Despite the tendency of high performers, such as Military Service Members and athletes, to consume large amounts of protein, it contributes very little fuel during exercise. Protein, in the form of amino acids, provides approximately 2–4% of energy during prolonged exercise, and carbohydrates and fat contribute the rest. However, protein is essential in providing minerals and amino acids to support the repair and growth of every cell in the body, especially muscles.

Protein for performance

Taking in adequate calories to meet energy needs allows the body to use carbohydrates and fats as energy sources instead of protein. If Warfighters don’t consume enough calories to meet the body’s needs, protein is used for energy rather than muscle repair and growth. This is an inefficient and expensive way to fuel, so the “right amount” of protein can improve optimal performance and recovery.

A common misconception among Military Service Members is the amount of protein needed for optimal performance. Protein needs differ based on body weight, frequency of workouts, and types of workouts. Warfighters might not consider protein intake from all sources (vegetables and grains) in their diet and consume more than they think and more than is needed for optimal performance. Excess protein intake might be at the expense of other macronutrients such as carbohydrates.

Daily protein requirements to support muscle growth, recovery, and repair for Military Service Members range from 0.8–1.6 g/kg (0.4–0.7 g/lb) body weight. Military Service Members should consume protein at the higher end of the range with intensified training, more frequent training, new training stimulus, if they’re less trained, or when energy intake (calories) is low.

When calorie intake isn’t enough to meet energy needs, Warfighters might need up to 2 grams of protein/kg body weight to maintain muscle mass, strength, and performance. Some military operations can increase energy needs, decrease appetite, or both, causing a negative energy balance. Scenarios include extended operations, training, or missions in extreme environments such as heat, cold or altitude, or with heavy equipment loads.

However, under conditions of severe negative energy balance, even extra protein might not be enough to preserve muscle mass. It’s important to educate Warfighters to try to consume more calories from high-quality foods and drinks to help the body avoid using protein for energy when possible.

Examples of recommended protein intake ranges (0.8–1.6 g/kg [0.4–0.7 g/lb] body weight) for Military Service Members:

  • 50 kg (110 lb): 40–80 g
  • 70 kg (154 lb): 56–112 g
  • 100 kg (220 lb): 80–160 g

Most Warfighters can easily meet their protein needs—without the need for dietary supplements—by eating nutrient-dense foods such as lean meats (“round,” “loin,” or “sirloin” cuts), poultry, fish, beans, nuts, eggs, legumes, and dairy products. Grains and vegetables contain small amounts of protein as well.

Protein for recovery

For optimal recovery and muscle repair, it’s crucial for Military Service Members to consume adequate amounts of protein after strenuous activity, including resistance training, moderate- to high-aerobic activity, or mixed training sessions (military training and/or combat patrols). Ideal recovery fuel is a high-carb snack or meal with 15–30 g of protein (0.25–0.3 g/kg body weight) eaten within 2 hours after exercise. Warfighters should build in recovery snacks and meals as part of their overall eating plan and protein needs.

Sample menus and snacks to kick-start post-workout muscle repair with protein:

  • Deli turkey (2 oz) and cheddar cheese (1 oz) on whole-wheat bread (2 slices), 1 medium apple (24 g protein, 43 g carb)
  • Peanut butter (2 Tbsp) and jelly (2 Tbsp) on whole-wheat bread (2 slices), 8 oz 1% chocolate milk (23 g protein, 72 g carb)
  • Apple-cinnamon oatmeal (2 packets), 8 oz chocolate soymilk (16.5 g protein, 75 g carb)
  • 5.3 oz low-fat Greek yogurt with 1.4 oz almonds, ¼ cup raisins (21g protein, 51 g carb)

Build an eating plan

Help Military Service Members create a balanced eating plan of meals and snacks that include fruits, vegetables, grains, plant and animal sources of protein, and dairy. High-performance meals can help maintain energy for strong and effective training sessions and provide enough protein to support normal activities, repair damaged tissues, and promote muscle growth. Unbalanced intake, such as an overemphasis on consuming protein, can set up Warfighters to fall short in consuming adequate carbohydrates, fiber, or some vitamins and minerals.

To optimize protein absorption, aim for moderate amounts of high-quality protein throughout the day, instead of large amounts at one meal (such as dinner). Educate Military Service Members to consume protein from a variety of whole foods that contain vitamins, minerals, and other nutrients to boost performance and recovery.

It can be helpful to show Warfighters how much protein they’re already consuming and how food groups besides animal protein contribute to their protein total. Use this sample eating plan (140 g protein, 3000 calories), to illustrate a day’s worth of balanced meals and snacks and the corresponding amounts of protein. The following eating plan is based on a Warfighter who weighs 100 kg (220 lb) and is aiming for 1.3 g protein/kg body weight:

Pre-workout snack:

  • 1 medium banana (1 g protein)
  • Small whole-wheat bagel (9 g protein)
  • 2 Tbsp jelly
  • 20 fl oz water

= 400 calories / 10 g protein

Breakfast:

  • 2 large eggs (13 g protein)
  • 2 slices whole-wheat toast (10 g protein)
  • 1 Tbsp butter
  • 8 fl oz orange juice (2 g protein)

= 550 calories / 25 g protein

Lunch:

  • ½ Grilled Chicken Caesar wrap (20 g protein)
  • 5.3 oz low-fat Greek yogurt (12 g protein)
  • Carrots (1 g) with 2 Tbsp hummus (2 g protein) or peanut butter (7 g protein)
  • 1 large apple
  • <16 fl oz unsweetened iced tea

= 790–910 calories / 35–40 g protein

Snack:

  • 1 oz cheese (8 g protein)
  • 6 whole-grain crackers (3 g protein)
  • 8 fl oz 1% chocolate milk (9 g protein)

= 360 calories / 20 g protein

Dinner:

  • 5 oz baked fish (37 g protein)
  • 1 cup brown rice (5 g protein)
  • 1 cup roasted broccoli (4 g protein)
  • 1 cup vanilla ice cream (5 g protein)
  • 8 fl oz water

= 740 calories / 51 g protein

Protein supplements

Encourage Military Service Members to choose high-quality protein foods whenever possible. However, protein supplements might be indicated when these foods are unavailable, inconvenient, or unable to meet current protein needs. Teach Warfighters to read food labels too, so they know exactly what they’re consuming. Also, advise Military Service Members looking for a protein supplement to choose a whey, casein, protein blend, or plant-based product that’s third-party certified.

For more information:

Resources

Headquarters Departments of the Army, the Navy, and the Air Force. (2017). AR 40–25 OPNAVINST 10110.1/MCO 10110.49 AFI 44–141: Nutrition and menu standards for human performance optimization. Washington, DC. Retrieved from https://armypubs.army.mil/epubs/DR_pubs/DR_a/pdf/web/AR40-25_WEB_Final.pdf.

Pasiakos, S. M., Austin, K. G., Lieberman, H. R., & Askew, E. W. (2013). Efficacy and safety of protein supplements for U.S. Armed Forces personnel: Consensus statement. The Journal of Nutrition, 143(11), 1811S–1814S. doi:10.3945/jn.113.176859

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. doi:10.1016/j.jand.2015.12.00