Whey Protein for Sports & Fitness
Also known as: Protein [Whey]
What is it?
Whey protein is a mixture of some of the proteins naturally found in milk. The major
proteins found in whey protein include beta-lactoglobulin and alpha-lactalbumin. Whey protein
has one of the highest protein digestibility-corrected amino acid scores (PDCAAS; a measure of
protein bioavailability) and is more rapidly digested than other proteins, such as casein
(another milk protein). 1
Where is it found?
During the process of making milk into cheese, whey protein is separated from the milk.
This whey protein is then incorporated into ice
cream, bread, canned soup, infant
formulas, and other food products. Supplements containing whey protein are also available.
Why do athletes use it?*
Some athletes say that whey protein
- serves as another protein choice in their diets.
What do the advocates say?*
Protein is necessary for rebuilding tissue—this is especially important for
bodybuilders. All types of protein provide the body with amino acids. From an athletic point
of view, whey is just another type of protein. Choosing whey protein over other types of
protein simply adds variety to the protein choices available.
Whey is a common ingredient in many meal replacements, which are designed to provide a
large amount of nutrients in a minimal amount of calories.
How much is usually taken by athletes?
Animal studies suggest that whey protein can increase gains in lean body mass resulting
from exercise.2 A controlled trial found that six weeks of strength training while
taking 1.2 grams of whey protein per 2.2 of pounds body weight per day resulted in greater
gains in lean body mass, but improved only one out of four strength tests.3 Another
controlled study found that people taking 20 grams per day of whey protein for three months
performed better on a test of short-term intense cycling exercise than people taking a similar
amount of milk protein (casein).4 However, a double-blind trial found that men
taking 1.5 grams per 2.2 lbs of body weight per day of predigested whey protein for 12 weeks
along with a strength-training exercise program gained only half as much lean body mass and
had significantly smaller increases in strength compared with men using a similar amount of
predigested casein along with strength training.5 A controlled study of
HIV-infected women found that adding whey protein to strength-training exercise was no more
effective than exercise alone for increasing strength or improving body
composition.6
Are there any side effects or interactions?
People who are allergic to dairy products
could react to whey protein and should, therefore, avoid it.7 As with protein in
general, long-term, excessive intake may be associated with deteriorating kidney function and
possibly osteoporosis. However, neither kidney
nor bone problems have been directly associated with consumption of whey protein, and the
other dietary sources of protein typically contribute more protein to the diet than does whey
protein. The possibility that certain proteins in milk may contribute to the development of
diabetes in children is controversial. But since whey proteins include some of the same milk
proteins, people who are avoiding milk because of concerns about the risk of diabetes should
not consume whey protein either.
At the time of writing, there were no well-known drug interactions
with whey protein.
*Athletes and fitness advocates may claim benefits for whey protein
based on their personal or professional experience. These are individual opinions and
testimonials that may or may not be supported by controlled clinical studies or published
scientific articles on whey protein. For more complete and detailed information, including
references and safety information, see Whey
Protein as a nutritional supplement.
References:1. Dangin M, Boirie Y, Guillet C, Beaufrere B. Influence of the protein
digestion rate on protein turnover in young and elderly subjects. J Nutr
2002;132:3228S–33S [review].
2. Bouthegourd JC, Roseau SM, Makarios-Lahham L, et al. A preexercise
alpha-lactalbumin-enriched whey protein meal preserves lipid oxidation and decreases adiposity
in rats. Am J Physiol Endocrinol Metab 2002;283:E565–72.
3. 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;11:349–64.
4. Lands LC, Grey VL, Smountas AA. Effect of supplementation with a
cysteine donor on muscular performance. J Appl Physiol 1999;87:1381–5.
5. Demling RH, DeSanti L. Effect of a hypocaloric diet, increased protein
intake and resistance training on lean mass gains and fat mass loss in overweight police
officers. Ann Nutr Metab 2000;44:21–9.
6. Agin D, Gallagher D, Wang J, et al. Effects of whey protein and
resistance exercise on body cell mass, muscle strength, and quality of life in women with HIV.
AIDS 2001;15:2431–40.
7. Wal JM. Cow's milk proteins/allergens. Ann Allergy Asthma Immunol
2002;89(6 Suppl 1):3–10.