Does a ketogenic diet make you a better athlete?

Seven people ate a ketogenic diet for three months straight. Here's what happened.

A lot of attention has been given to the ketogenic diet recently. While positioned as an ideal means of losing weight, studies have also been conducted on its benefits for cognitive function, as well as how simply changing your diet without exercising outperforms the “standard American diet” even with exercise. 

A recent study, published in the journal Sports, poses a different question: Can the ketogenic diet make you a better athlete? A team based at the School of Kinesiology at Auburn University asked 12 participants to partake in a 12-week study to measure body composition, metabolic, and performance parameters in CrossFit practitioners.

It should be noted that 12 volunteers make for a small group. When broken down—seven in the keto group, five in the control—this represents a tiny sample size. That said, asking volunteers to eat a specific way for 12 weeks can be a daunting challenge. As a pilot study, the results are informative, but a larger-scale study would have to be conducted before specific health or performance claims are made. 

The researchers wanted to better understand how the ketogenic diet affects resistance training, as a previous study with mice demonstrated that a low-carbohydrate diet reduces muscle mass. The authors addressed this controversy by pointing to their own six-week study with mice, noting that a ketogenic diet does not impair muscle glycogen levels or affect muscle protein synthesis in comparison to an isocaloric Western diet (consuming the same quantity of calories from fats, proteins, and carbohydrates each day).

Previous studies with gymnasts and bodybuilders conclude that ketogenic diets do not decrease muscle mass in humans. They also cite a six-week study of non-elite CrossFit athletes showing that while fat mass reduced by an average of 2.8 kg, they did not suffer any losses of lean body mass. 

For this study, seven volunteers in the ketogenic group were asked to return food logs after being given basic keto dietary guidelines. Only four complied, but given blood ketone levels measured in abstaining volunteers, researchers were confident they’d followed the diet for the duration of the study. The control group did not have to keep track of food intake. 

High-fat foods like avocados are staples of the ketogenic diet. (Photo by Mark Ralston/AFP/Getty Images)

Over the course of 12 weeks, the keto group completed a higher average of workouts than the control group, which could have influenced results or could have been because of the diet—oddly, no mention is made as to why different workout schedules were kept. As with the tracking of food logs, this could skew results. Still, the researchers felt comfortable proclaiming that a ketogenic diet does not reduce muscle mass even as fat is shed. 

Individuals who train recreationally at a CrossFit gym while adopting a KD for 12 weeks experience a reduction in whole-body adiposity with little influence on metabolic or exercise performance measures.

As for performance, not much changed. While both groups did not experience decreased performance results, the keto group did not outperform the control group in terms of strength or cardiovascular gains. They note that a keto diet did not adversely affect anaerobic performance.

In terms of overall performance, the researchers agree that many dietary avenues can be considered healthy and lead to optimal athleticism. They instead put the diet's importance on weight loss and/or body composition results, suggesting that on those grounds the keto diet should be considered. 

We contend that the human body is capable of adapting to several different diets during periods of exercise training, and performance may not be compromised so long as caloric needs are met. Notwithstanding, given that KD-induced anaerobic and aerobic performance improvements were not evident herein or in other published reports, we contend that practitioners should explore implementing this diet when body composition improvements are sought rather than performance benefits.


Derek Beres is the author of Whole Motion and creator of Clarity: Anxiety Reduction for Optimal Health. Based in Los Angeles, he is working on a new book about spiritual consumerism. Stay in touch on Facebook and Twitter.

LinkedIn meets Tinder in this mindful networking app

Swipe right to make the connections that could change your career.

Getty Images
Swipe right. Match. Meet over coffee or set up a call.

No, we aren't talking about Tinder. Introducing Shapr, a free app that helps people with synergistic professional goals and skill sets easily meet and collaborate.

Keep reading Show less

26 ultra-rich people own as much as the world's 3.8 billion poorest

The Oxfam report prompted Anand Giridharadas to tweet: "Don't be Pinkered into everything's-getting-better complacency."

Getty Images and Wikimedia Commons
Politics & Current Affairs
  • A new report by Oxfam argues that wealth inequality is causing poverty and misery around the world.
  • In the last year, the world's billionaires saw their wealth increase by 12%, while the poorest 3.8 billion people on the planet lost 11% of their wealth.
  • The report prompted Anand Giridharadas to tweet: "Don't be Pinkered into everything's-getting-better complacency." We explain what Steven Pinker's got to do with it.
Keep reading Show less

People who constantly complain are harmful to your health

Moans, groans, and gripes release stress hormones in the brain.

Photo credit: Getty Images / Stringer

Could you give up complaining for a whole month? That's the crux of this interesting piece by Jessica Hullinger over at Fast Company. Hullinger explores the reasons why humans are so predisposed to griping and why, despite these predispositions, we should all try to complain less. As for no complaining for a month, that was the goal for people enrolled in the Complaint Restraint project.

Participants sought to go the entirety of February without so much as a moan, groan, or bellyache.

Keep reading Show less
  • Facebook and Google began as companies with supposedly noble purposes.
  • Creating a more connected world and indexing the world's information: what could be better than that?
  • But pressure to return value to shareholders came at the expense of their own users.
Keep reading Show less