• Don’t Get Fooled Again #5 – Athletes on a high-carb diet don’t produce ketones.

    This is our fifth installment in the Don’t Get Fooled Again series. Thanks so much for the participation and discussion! I’ve had several messages letting me know the series has been fun/good.

    For today, it’s ketones. One of the benefits of a low-carb, high-fat diet is the production of ketones. The body can use ketones as a supply of energy, rather than relying on using so much glucose. Here is the statement:

    Endurance athletes following a high-carb, low-fat diet do not produce ketones. (True or False?)


    Alan Schenkel nailed this one in the Facebook group discussion.

    False. Ketones are produced in at least five situations, 1) while following a low-carb diet, 2) during periods of fasting, 3) during periods of starvation and 4) during certain types of exercise and 5) during certain combinations of 1-4.

    The graph below shows circulating concentrations of several markers in the blood for both low-carb (LCD) and high-carb diet (HCD) athletes. The samples were taken before, during and after a 3-hour treadmill run. For this edition of DGFA, notice that even over the course of 60 minutes, ketone levels rise in both groups – and as Alan pointed out – the HCD group’s ketone levels didn’t reach as high as did the LCD group.

    The run was 180 minutes in length. Notice the highest levels of ketones in the blood were measured post-exercise. This phenomena is well-documented, called the Courtice-Douglas Effect.

     (Click on graph to enlarge)


    Reference for charts:

    Volek JS, et al, “Metabolic characteristics of keto-adapted ultra-endurance runners,” Metabolism. 2016 Mar;65(3):100-10. doi: 10.1016/j.metabol.2015.10.028. Epub 2015 Nov 2.

    Be sure to see if I have an easy-to-use training plan for you on my site to help you reach your goals. And, there are more options on the TrainingPeaks site.


    Don’t Get Fooled Again – Workout recovery

    Don’t Get Fooled Again – Can the brain only use glucose?

    Don’t Get Fooled Again – Is it legal to use the title “Dr.” when you are not a medical doctor?

    Don’t Get Fooled Again – Vegetables are not carbohydrates
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