Saturday, March 21, 2009

Resistance training with soy vs. whey protein supplements in hyperlipidemic males

Carol A. DeNysschenHarold W. BurtonPeter J. HorvathJohn A. Leddy and Richard W. Browne 

Journal of the International Society of Sports Nutrition 2009, 6:8doi:10.1186/1550-2783-6-8

Published:11 March 2009

Abstract (provisional)


Most individuals at risk for developing cardiovascular disease (CVD) can reduce risk factors through diet and exercise before resorting to drug treatment. The effect of a combination of resistance training with vegetable-based (soy) versus animal-based (whey) protein supplementation on CVD risk reduction has received little study. The study's purpose is to examine the effects of 12 weeks of resistance exercise training with soy versus whey protein supplementation on strength gains, body composition and serum lipid changes in overweight, hyperlipidemic men.


Twenty-eight overweight, male subjects (BMI 25-30) with serum cholesterol >200 mg/dl were randomly divided into 3 groups (placebo (n=9), and soy (n=9) or whey (n=10) supplementation) and participated in supervised resistance training for 12 weeks. Supplements were provided in a double blind fashion.


All 3 groups had significant gains in strength, averaging 47% in all major muscle groups and significant increases in fat free mass (2.6%), with no difference among groups. Percent body fat and waist-to-hip ratio decreased significantly in all 3 groups an average of 8% and 2%, respectively, with no difference among groups. Total serum cholesterol decreased significantly, again with no difference among groups.


Participation in a 12 week resistance exercise training program significantly increased strength and improved both body composition and serum cholesterol in overweight, hypercholesterolemic men with no added benefit from protein supplementation.


This paper seems to be pretty basic. It does conclusively show what we all know to be true: resistance training will significantly improve body composition and health markers especially in those that are untrained and overweight. It specifically looked at the additional benefits of protein supplementation of whey vs. soy.  Its understandable that there would be no difference between soy and whey in these men but what was remarkable to me is that the no protein supplementation group had the same benefits.  This could be due to the fact that the benefits seen from weight training are going to be huge no matter what because they are so untrained and overweight that you wouldn't be able to see the significantly additional benefits from protein supplementation until they are no longer novices.  It would be interesting to me to see a long term study of soy vs. whey vs. none, such as a 1-2 year study that examined the differences in body comp and serum cholesterol.

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