Effect of protein source and resistance training on body composition and sex hormones
2007

Effects of Protein Source and Resistance Training on Body Composition

Sample size: 20 publication Evidence: moderate

Author Information

Author(s): Kalman Douglas, Feldman Samantha, Martinez Michele, Krieger Diane R, Tallon Mark J

Primary Institution: Miami Research Associates, Nutrition/Endocrinology Division, Miami, Florida, USA

Hypothesis

Does the type of protein source affect body composition and sex hormone levels in men undergoing resistance training?

Conclusion

Supplementation with soy protein does not negatively impact testosterone levels or lean body mass gains during resistance training.

Supporting Evidence

  • Protein supplementation resulted in a significant increase in lean body mass.
  • No significant differences were observed between groups for total and free testosterone.
  • The Testosterone/Estradiol ratio increased across all groups.
  • Estradiol levels decreased significantly in the whey blend group.

Takeaway

Eating protein while exercising helps you get stronger, and it doesn't matter if the protein comes from soy or milk.

Methodology

20 subjects were supplemented with different protein sources while participating in a 12-week resistance training program.

Potential Biases

Potential dietary intake inaccuracies and lack of controlled diets may introduce bias.

Limitations

The study had a small sample size and was not powered for definitive conclusions.

Participant Demographics

Healthy males aged 18-40 with a BMI of less than 40 kg/m2.

Statistical Information

P-Value

0.006, 0.007, 0.005, 0.002, 0.030, 0.033

Statistical Significance

p<0.05

Digital Object Identifier (DOI)

10.1186/1550-2783-4-4

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