Recent research published in the Journal of the International Society of Sports Nutrition calls into question the notion that very low-carb ketogenic diets are unsuitable for athletes because they will not be able to achieve commensurate levels of performance without an adequate supply of glucose (derived from carbohydrate ingestion).

The researchers took 8 athletes, measured their performance in a variety of exercises while eating a standard Western diet, then they they put the athletes on a Very Low Carbohydrate Ketogenic Diet for thirty days and measured their performance on the same exercises. The result? Fascinating:

No significant differences were detected between VLCKD and WD in all strength tests. Significant differences were found in body weight and body composition: after VLCKD there was a decrease in body weight (from 69.6 +/- 7.3 Kg to 68.0 +/- 7.5 Kg) and fat mass (from 5.3 +/- 1.3 Kg to 3.4 +/- 0.8 Kg p < 0.001) with a non-significant increase in muscle mass.

That’s right, no detectable difference in performance. None. Nada. Zip. Oh yeah, the ketogenic low-carb dieters also lost fat while keeping muscle mass constant.

One obvious limitation to this study is that it appears to be focused on resistance exercise. I wonder what the results would be for runners… Thoughts?

Resources

• Ketogenic diet does not affect strength performance in elite artistic gymnasts, Paoli, Grimaldi, et al. Journal of the International Society of Sports Nutrition 2012, 9:34 doi:10.1186/1550-2783-9-34 Published: 26 July 2012 (Note: This is the research abstract. Link to the full research article is included on the page.)