Penn Herb Wellness Guide
Whey Protein for Sports & FitnessFind Products
How Much Is Usually Taken by Athletes?
Animal studies suggest that whey protein can increase gains in lean body mass resulting from exercise.1 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.2 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).3 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.4 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.5
Side Effects
People who are allergic to dairy products could react to whey protein and should, therefore, avoid it.6 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.
Interactions with Supplements, Foods, & Other Compounds
Interactions with Medicines
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The information presented by TraceGains is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. Self-treatment is not recommended for life-threatening conditions that require medical treatment under a doctor's care. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires December 2025.