Food for thought: Ketogenic diets reduce athletes' anaerobic performance

May 1, 2018 by Carrie Bebermeyer, Saint Louis University
Researcher Edward Weiss, Ph.D., is an avid bicycler. Credit: Saint Louis University

Athletes who turn to ketogenic diets to help their performance in high-intensity, short duration sports may want to think again, according to new research from Saint Louis University.

In a small study, Edward Weiss, Ph.D., associate professor of nutrition and dietetics at Saint Louis University, together with SLU graduate students Kym Wroble, R.D. and Morgan Trott, R.D., examined the exercise of 16 men and women after following either a or a high-carbohydrate for four days. His team then tested the anaerobic exercise performance of the participants.

The research team found that after following the ketogenic diet, the participants did not perform as well at the exercise tasks.

"In popular discussions, the term 'ketogenic diet' often is used as a broader term for , including Atkins," Weiss said. "However, the language is often confused. People often think low carb and high protein. This is related, but different, as protein can only be at normal levels for a true ketogenic diet.

"The objective of a ketogenic diet is to starve the body of carbohydrate. If there is too much protein in the diet, the body will use the protein to make carbohydrates, which defeats the purpose. When the body is sufficiently deprived of carbohydrate, it manufactures ketone bodies as an alternate fuel. It's an emergency backup system that allows us to survive when we are at risk of starvation. But, it has side effects.

"Right now in the general public, it's touted for . Some studies have shown that it is effective for weight loss. I worry, though, that this may be a lot of smoke and mirrors. A typical diet is 60 percent carbohydrate. So, if you limit carbs, you might find yourself just not eating that much. If you eliminate most food options, you may just be losing weight because you are cutting calories."

The study has implications both for those who turn to ketogenic diets for weight loss and for athletes who aim to improve their performance.

"The energy metabolism system that's affected is anaerobic. Watching the summer Olympics, the 100 meter sprint and the triple jump depend on this system. You might say that this doesn't relate to me. But for someone with low fitness, they use this same metabolism to get up the stairs. Everyday people use this kind of metabolism without realizing it. This study shows that this energy system is compromised by this type of diet."

Weiss has one caveat.

"There are populations that a may benefit," Weiss said. "For example, patients who have epilepsy benefit from this diet. For those with abnormal cell metabolism that causes seizures, causing cells to feed on ketones instead can be helpful."

The bottom line?

"Short-term low carbohydrate, ketogenic diets reduce in activities that are heavily dependent on anaerobic energy systems," Weiss reports. "These findings have clear performance implications for athletes, especially for high-intensity, short duration activities and sports.

"This diet is especially hot among people who are trying to optimize their health. What this study tells me is that unless there are compelling reasons for following a low-carb diet, athletes should be advised to avoid these diets."

Explore further: Low-carb, high-fat diets may reduce seizures in tough-to-treat epilepsy

More information: Low-carbohydrate, ketogenic diet impairs anaerobic exercise performance in exercise-trained women and men: a randomized-sequence crossover trial, DOI: 10.23736/S0022-4707.18.08318-4

Related Stories

Low-carb, high-fat diets may reduce seizures in tough-to-treat epilepsy

October 29, 2014
Diets high in fat and low in carbohydrates, such as the ketogenic or modified Atkins diet, may reduce seizures in adults with tough-to-treat epilepsy, according to a review of the research published in the October 29, 2014, ...

Do ketogenic diets help you lose weight?

September 20, 2017
Is a ketogenic diet effective for weight loss? The answer depends on whether it achieves a reduction in total kilojoule intake or not.

How ketogenic diets curb inflammation

September 25, 2017
Ketogenic diets – extreme low-carbohydrate, high-fat regimens that have long been known to benefit epilepsy and other neurological illnesses – may work by lowering inflammation in the brain, according to new research ...

Eat fat, live longer? Mouse study shows a high fat diet increases longevity, strength

September 5, 2017
As more people live into their 80s and 90s, researchers have delved into the issues of health and quality of life during aging. A recent mouse study at the UC Davis School of Veterinary Medicine sheds light on those questions ...

Ketogenic diet improves healthspan and memory in aging mice

September 5, 2017
A ketogenic diet significantly improved memory in aging mice and increased the animal's chances of surviving to old age. Results of the study from Eric Verdin's lab at the Buck Institute for Research on Aging in Novato, CA ...

Low-fat diet, low-carb diet—or 'low both'?

November 9, 2017
(HealthDay)—Low-carb diets are often thought of as fad diets that might yield a rapid initial weight loss, but aren't sustainable or necessarily healthy. But when there's academic research behind the approach, it's worth ...

Recommended for you

Closing coal, oil power plants leads to healthier babies

May 22, 2018
Shuttering coal- and oil-fired power plants lowers the rate of preterm births in neighboring communities and improves fertility, according to two new University of California, Berkeley, studies.

Insufficient sleep, even without extended wakefulness, leads to performance impairments

May 21, 2018
Millions of individuals obtain insufficient sleep on a daily basis, which can lead to impaired performance and other adverse physiological outcomes. To what extent these impairments are caused by the short sleep duration ...

Avoiding the car for travel could significantly lower risk of illness and death

May 21, 2018
People who are more active when commuting to work by walking or cycling could be cutting their relative risk of developing ischaemic heart disease or stroke by 11% and their relative risk of dying from these diseases by 30%, ...

New study shows higher formaldehyde risk in e-cigarettes than previously thought

May 21, 2018
Portland State University researchers who published an article three years ago in the New England Journal of Medicine about the presence of previously undiscovered forms of formaldehyde in e-cigarette vapor revisited their ...

Sleep better, parent better: Study shows link between maternal sleep and permissive parenting

May 21, 2018
Research has shown that consistently not getting enough sleep, or getting poor quality sleep, can put you at risk for a number of health conditions. But how does sleep, or the lack of it, affect how you parent?

Mediterranean diet may blunt air pollution's ill health effects

May 21, 2018
Eating a Mediterranean diet may protect people from some of the harm of long-term exposure to air pollution, and reduce their risk of dying from heart attacks, stroke and other causes of death, according to new research presented ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.