REMINDER: Siteowner has no obligation to monitor the Forums. However, Siteowner reserves the right to review the Materials submitted to or posted on the Forums, and remove, delete, redact or otherwise modify such Materials, in its sole discretion and for any reason whatsoever, at any time and from time to time, without notice or further obligation to you. Siteowner has no obligation to display or post any Materials provided by you. Siteowner reserves the right to disclose, at any time and from time to time, any information or Materials that Siteowner deems necessary or appropriate to satisfy any applicable law, regulation, contract obligation, legal or dispute process or government request. To further read the rules and terms of agreement of this Forum, click here.
Recently, researchers wanted to see if a low-carb diet could alter this effect (18, 19).
Their study found that ketogenic athletes burned mostly fat at up to 70% of max intensity, vs only 55% in the high-carb athletes. In fact, the ketogenic athletes in this study burned the most fat ever recorded in a research setting (17).
Yet despite these positive findings, fat may be unable to produce energy fast enough to meet the demands of the muscles of elite athletes (27, 28, 29).
Nevertheless, studies have found that low-carb diets can help prevent tiredness during prolonged exercise. They may also help you lose fat and improve health, without compromising low-to-moderate intensity exercise performance (4, 30, 31).
Furthermore, these diets can teach your body to burn more fat, which may help you preserve muscle glycogen during exercise (17).
BOTTOM LINE: A low-carb diet is likely to be just fine for most people exercising at low-to-moderate intensities. However, more research is needed for high-level athletes. How Carbs Affect Muscle Growth As of now, no research has shown that low-carb or ketogenic diets are better for high-intensity, strength or power-based sports.
This is because carbs aid muscle growth and high-intensity exercise performance in several ways:
Promote recovery: Carbs may help with recovery after exercise (32). Produce insulin: Carbs also produce insulin, which helps with nutrient delivery and absorption (33). Provide fuel: Carbs play an important role in the anaerobic and ATP energy systems, which are the primary fuel sources for high-intensity exercise (34). Reduce muscle breakdown: Carbs and insulin help reduce muscle breakdown, which may improve net protein balance (35, 36). Improve neural drive: Carbs also improve neural drive, resistance to fatigue and mental focus during exercise (37). However, this doesn't mean your diet must be very high in carbs, like a typical Western diet. A moderate-carb or carb cycling diet may work well for most sports./p>
In fact, a moderate-carb, higher-protein diet seems to be optimal for muscle growth and body composition for people who are lean and active (38).
BOTTOM LINE: Carbs play an important role in muscle growth and high-intensity exercise performance. There is no research showing low-carb diets to be superior for this. Studies on Low-Carb Diets for Athletes Several studies have looked into the effects of low-carb diets on high-intensity endurance exercise.
However, they have provided mixed results.
One study found no difference between the ketogenic and high-carb groups for high-intensity sprints.
Yet the ketogenic group did get less tired during low-intensity biking, which is probably because the body used more fat for fuel (39).
Other studies have shown that people on low-carb diets can spare muscle glycogen and use more fat as fuel, which could be beneficial for ultra-endurance sports (18).
Nevertheless, these findings have less relevance for athletes performing high-intensity exercise or workouts of less than 2 hours.
The research is also mixed in obese populations, with some studies showing benefits in lower-intensity aerobic exercise, while others show a negative effect (31, 40).
Some studies have found that individual response may vary as well. For example, one study found that some athletes achieved better endurance performance, while others experienced drastic decreases (41).
At the present time, the research does not show that a low-carb or ketogenic diet can improve high-intensity sports performance, compared to a higher-carb diet.
Yet for lower-intensity exercise, a low-carb diet can match a conventional high-carb diet and even help you use more fat as fuel (31).
BOTTOM LINE: Low-carb and ketogenic diets do not seem to benefit high-intensity exercise performance. However, these diets seem to match high-carb diets when it comes to lower-intensity exercise. Are There Any Additional Benefits for Athletes? One beneficial aspect of a low-carb or ketogenic diet is that it teaches the body to burn fat as fuel (42).
For endurance athletes, research has shown that this can help preserve glycogen stores and keep you from "hitting the wall" during endurance exercises (18, 42).
This helps you rely less on carbs during a race, which could be important for athletes who struggle to digest and consume carbs during exercise. It may also be beneficial during ultra-endurance events where access to food is limited (18).
Additionally, several studies have shown that low-carb and ketogenic diets can help people lose weight and improve overall health (43, 44).
Fat loss can also improve your fat to muscle ratio, which is extremely important for exercise performance, especially in weight-dependent sports (45, 46).
Exercising with low glycogen stores has also become a popular training technique, known as "train low, compete high" (47).
This can improve fat utilization, mitochondria function and enzyme activity, which have a beneficial role in health and exercise performance (47).
For this reason, following a low-carb diet for a short period of time -- such as during an "off season" -- may aid long-term performance and health.
BOTTOM LINE: Low-carb diets may be useful for some types of endurance exercise. They can also be used strategically to improve body composition and health. Take Home Message Low-carb or ketogenic diets can be a good choice for healthy people who are mostly exercising and lifting to stay healthy.
However, there is currently no solid evidence that they improve performance over higher-carb diets in athletes.
That being said, the research is still in its infancy, and some early results suggest that they can be a good choice for low-intensity exercise or ultra-endurance exercise.
At the end of the day, carb intake should be tailored to you as an individual.
Written by Rudy Mawer, MSc, CISSN on May 29, 2017
The Wild Diet Review: Does It Work for Weight Loss?
Anti-Inflammatory Diet 101: How to Reduce Inflammation Naturally
The Dukan Diet Review: Does It Work for Weight Loss?
17 Day Diet Review: Does It Work for Weight Loss?
HMR Diet Review: Does It Work for Weight Loss?
Mediterranean Diet 101: A Meal Plan and Beginner's Guide
The Best Indian Diet Plan for Weight Loss
The Ketogenic Diet: A Detailed Beginner's Guide to Keto
Vegetarian Diets May Be Even Better for Us Than We Thought