PrintProtein: What You Need to Know

In its most recent position stand on protein, the International Society of Sports Nutrition, or ISSN, wrote that exercising individuals need approximately 1.4 to 2.0 grams of protein per kilogram of body weight per day (1). For a 180-pound male, this translates into a range of approximately 115 to 165 grams of protein.

Clearly, the protein recommendations for those involved in exercise is higher than the Recommended Dietary Allowance (RDA) of 0.8 grams of protein per kilogram of bodyweight per day. With intakes roughly double the RDA, controversy exists over the safety and effectiveness for elevated protein intakes. Here’s what you need to know about protein if performance and exercise is your goal.

Safety of Protein Intakes Higher Than RDA

Multiple literature reviews indicate that no controlled scientific evidence exists showing that increased intakes of protein pose any health risks in healthy, exercising individuals (1). In fact, a series of published research articles prescribed extremely high amounts of protein (3.4 to 4.4 g/kg/day) and have consistently reported no harmful effects (2-5).

For an exercising individual, 1.4 to 2.9 grams of protein per kilogram of bodyweight per day is safe. Importantly, this recommendation also falls within the Institute of Medicine’s Acceptable Macronutrient Distribution Range (AMDR) of 10-35 percent protein (6).

Effects on Performance

Results from multiple investigations report that a higher protein intake has a significant impact on strength and performance (1). Even endurance athletes can benefit from a higher level of protein intake. Adding protein to a carbohydrate beverage during exhaustive endurance exercise suppresses markers of muscle damage post exercise and decreases muscular soreness (1). Furthermore, adding protein to carbohydrate consumption throughout a prolonged bout of endurance exercise promotes a higher whole body net protein balance.

Body Composition

Improving body composition through the loss of fat mass and increasing lean body mass is often associated with improvements in physical performance. Protein supplementation has shown over many decades of research to result in significant improvements in lean body mass in comparison to placebo treatments (7-12). When combined with a resistance-training program, an elevated daily intake of protein can promote greater losses of fat mass and greater overall improvements in body composition.

Protein Timing

The ISSN recommends at least 20-25 grams of protein with each main meal for exercising individuals. They also recommend eating every three to four hours (13).

Previous research found that ingesting a protein before and following exercise is beneficial for increasing muscle mass, recovery following exercise, and sustaining immune function during high-volume training periods.

Current research has found protein consumed throughout the day is important since recovery from exercise lasts 24-72 hours (1). This parallels results from research conducted on Isagenix performance products by exercise and nutrition researcher Paul Arciero who found elevated protein paced over the day improved markers of performance in both men and women (14, 15).

Protein Quality

Supplementing with whey protein provides a distinct advantage over other protein sources on muscle protein synthesis. Whey protein contains an array of biologically active peptides whose amino acid sequences give them specific signaling effects to support muscle maintenance, muscle adaptation, and quality of sleep for improved recovery (16-20).


  1. Jäger R, Kerksick CM, Campbell BI et al. International Society of Sports Nutrition Position Stand: protein and exercise. J Int Soc Sports Nutr. 2017 Jun 20; 14:20.
  2. Antonio J, Ellerbroek A, Silver T et al. A high protein diet (3.4 g/kg/d) combined with a heavy resistance training program improves body composition in healthy trained men and women–a follow-up investigation. J Int Soc Sports Nutr. 2015 Oct 20; 12:39.
  3. Antonio J, Ellerbroek A, Silver T et al. The effects of a high protein diet on indices of health and body composition–a crossover trial in resistance-trained men. J Int Soc Sports Nutr. 2016 Jan 16; 13:3.
  4. Antonio J, Ellerbroek A, Silver T et al. A high protein diet has no harmful effects: a one-year crossover study in resistance-trained males. J Nutr Metab. 2016;2016:9104792.
  5. Antonio J, Peacock CA, Ellerbroek A et al. The effects of consuming a high protein diet (4.4 g/kg/d) on body composition in resistance-trained individuals. J Int Soc Sports Nutr. 2014 May 12; 11:19.
  6. Wolfe RR, Cifelli AM, Kostas G et al. Optimizing protein intake in adults: interpretation and application of the recommended dietary allowance compared with the acceptable macronutrient distribution range. Adv Nutr. 2017 Mar 15;8(2):266-275
  7. Andersen LL, Tufekovic G, Zebis MK et al. The effect of resistance training combined with timed ingestion of protein on muscle fiber size and muscle strength. Metab Clin Exp. 2005 Feb;54(2):151-6.
  8. Burke DG, Chilibeck PD, Davidson KS et al. The effect of whey protein supplementation with and without creatine monohydrate combined with resistance training on lean tissue mass and muscle strength. Int J Sport Nutr Exerc Metab. 2001 Sep;11(3):349-64.
  9. Hulmi JJ, Kovanen V, Selanne H et al. Acute and long-term effects of resistance exercise with or without protein ingestion on muscle hypertrophy and gene expression. Amino Acids. Jul;37(2):297-308.
  10. Kerksick CM, Rasmussen CJ, Lancaster SL et al. The effects of protein and amino acid supplementation on performance and training adaptations during ten weeks of resistance training. J Strength Cond Res. 2006 Aug;20(3):643-53
  11. Candow DG, Burke NC, Smith-Palmer T et al. Effect of whey and soy protein supplementation combined with resistance training in young adults. Int J Sport Nutr Exerc Metab. 2006 Jun;16(3):233-44.
  12. Cribb PJ, Williams AD, Stathis CG et al. Effects of whey isolate, creatine, and resistance training on muscle hypertrophy. Med Sci Sports Exerc. 2007 Feb;39(2):298-307.
  13. Areta JL, Burke LM, Ross ML et al. Timing and distribution of protein ingestion during prolonged recovery from resistance exercise alters myofibrillar protein synthesis. J Physiol. 2013 May 1;591(9):2319-31
  14. Arciero PJ, Ives SJ, Norton C et al. Protein-Pacing and Multi-Component Exercise Training Improves Physical Performance Outcomes in Exercise-Trained Women: The PRISE 3 Study. Nutrients. 2016 Jun 1;8(6).
  15. Ives SJ, Norton C, Miller V et al. Multi-modal exercise training and protein-pacing enhances physical performance adaptations independent of growth hormone and BDNF but may be dependent on IGF-1 in exercise-trained men. Growth Horm IGF Res. 2017 Feb; 32:60-70.
  16. Tang JE, Moore DR, Kujbida GW et al. Ingestion of whey hydrolysate, casein, or soy protein isolate: effects on mixed muscle protein synthesis at rest and following resistance exercise in young men. J App Physiol. 2009 Sep;107(3):987-92.
  17. West DW, Burd NA, Coffey VG et al. Rapid aminoacidemia enhances myofibrillar protein synthesis and anabolic intramuscular signaling responses after resistance exercise. Am J Clin Nutr. 2011 Sep;94(3):795-803.
  18. Staples AW, Burd NA, West DW et al. Carbohydrate does not augment exercise-induced protein accretion versus protein alone. Med Sci Sports Exerc. Med Sci Sports Exerc. 2011 Jul;43(7):1154-61.
  19. Markus CR, Olivier B, De Haan EH. Whey protein rich in alpha-lactalbumin increases the ratio of plasma tryptophan to the sum of the other large neutral amino acids and improves cognitive performance in stress-vulnerable subjects. Am J Clin Nutr. 2002 Jun;75(6):1051-6.
  20. Minet-Ringuet J, Le Ruyet PM, Tome D et al. A tryptophan-rich protein diet efficiently restores sleep after food deprivation in the rat. Behav Brain Res. 2004 Jul 9;152(2):335-40.