Protein Supplements as an Ergogentic Aid: Do They Really Work?

An ergogenetic aid is “any training technique, mechanical device, nutritional practice, pharmacological method, or psychological technique that can improve exercise performance capacity and/or enhance training adaptations” (Kreider et al, 2010).  Protein supplements are an ergogentic aid that have been heavily advertised to the general public and athletes as a great way to build muscle and enhance abilities.  However, there are three important questions to ask when evaluating these supplements:  1)  Is the theory plausible?  In other words, can protein supplements enhance performance and reduce muscle breakdown?  2) Is there scientific evidence to support the theory?  3)  Is the supplement safe and legal?  (Kreider et al, 2010)   

Most sources agree that an athlete should strive to get adequate protein from whole foods before turning to a supplemental form.  However, protein supplements may be a more convenient way for the athlete to consume his or her protein requirements, especially for vegetarian athletes (Dunford & Doyle, 2012).  A high-quality protein supplement is considered safe and effective at the recommended doses (Dunford & Doyle, 2012).

It has been found that whey, casein, or soy supplements are effective for the maintenance, repair, and synthesis of skeletal muscle proteins and can enhance maintenance and net gains in skeletal muscle (ADA, 2009).   Cooke et al conducted a study on whey protein isolate and found that adding whey protein supplements to their subjects’ diets increased isometric strength in the knees of those subjects (Cooke et al, 2010).   This study took seventeen untrained males and randomly selected them into two categories:  whey protein and carbohydrate.  The subjects were given 1.5g/kgbw/d for 14 days.   The study was run with a 95% confidence interval.  The subjects were tested with the leg press, leg extension, leg flexion, and checked for muscle damage (Cooke et al, 2010). 

The Cooke study supports the theory that a high-quality protein supplement enhances performance for athletes when additional protein is needed.  Athletes commonly go above the RDA of 0.8g/kgbw for protein, and endurance and ultra-endurance athletes should consume more protein due to an increase in protein oxidation (ADA, 2009).   Protein supplements providing “exogenous amino acids, especially within the first 4 hours after resistance exercise (as implemented in the [Cooke] study), increases protein synthesis, decreases protein breakdown, and produces a positive protein balance, thus providing an environment for muscle growth” (Cooke et al, 2010).  It is the use of a high-quality protein with appropriate amino acids that aids in the rebuilding, repairing, and endurance of the muscle.

While protein supplements may be beneficial to strength and muscle repair, it is still important to look for quality sources.  The best sources of protein supplements are casein, whey, mild and egg proteins, and colostrum (Kreider et al, 2010).  When choosing a protein supplement, it is also important to consider the amino acids in the supplement for maximum benefits and health (Dunford & Doyle, 2012).  It is also important to use a high-quality protein as was used in the Cooke study.  It is also important to remember that although protein supplements are considered safe and effective, they may not be necessary for the general public but are beneficial to the strength and endurance athlete.

ADA (2009)  Nutrition and Athletic Performance.  Journal of American Dietetic Association 2009; 109:509-527.

Cooke, Matthew; Rybalka, Emma; Stathis, Christos; Cribb, Paul; Hayes, Alan (2010)  Whey protein isolate attenuates strength decline after eccentrically-induced muscle damage in healthy individuals.  Journal of the International Society of Sports Nutrition 2101, 7:30

Dunford, Marie & Doyle, J. Andrew (2012)  Nutrition for Sport and Exercise, 2^nd ed.  Wadsworth Cengage Learning:  California

Kreider, Richard B.; Wilborn, Colin D.; Taylor, Lem; Campbell, Bill; Almada, Anthony; Collins, Rick; Cooke, Matthew; Earnest, Conrad; Greenwood, Mike; Kalman, Douglas; Kerksick, Chad; Kleiner, Susan; Leutholtz, Brian; Lopez, Hector; Lowrey, Lonnie; Mendel, Ron; Smith, Abbie; Spano, Marie; Wildman, Robert; Willoughby, Darryn; Ziegenfuss, Tim; Anfonio, Jose (2010).  ISSN exercise and sport nutrition review:  research and recommendations.  Journal of the International Society of Sports Nutrition 2010, 7:7