A new study from the Australian Institute of sport has put another nail in the coffin for the ketogenic diet for endurance athletes. High fat, very low carb diets have been touted as potentially increasing endurance performance for a number of reasons; we store more fat in our body than we could ever store carbohydrate, it has been proposed as ‘anti-inflammatory’, and it has even been suggested to help our muscles respond more to a given exercise stimulus. (If you’re not sure what a ketogenic diet is, we’ve written about it before with some examples)
To put it to the test though, the renowned Australian research group enlisted elite race-walkers (Olympic and world medalists were amongst the participants) and got them to consume either a high carbohydrate, a structured carbohydrate, or a ketogenic diet. They carried this study out and published the data a few years ago. They found that when the athlete’s performance in a race was worse when they had the ketogenic diet compared to the other two. When they assessed them in the lab, they found it cost them more energy to exercise at higher intensities – so their exercise economy was worse.
After publishing the data, they decided they would rerun the experiment to try and see if they could confirm the data.