The Ketogenic Diet and Exercise

The ketogenic diet has been helping many people heal from health issues. You eventually have to address poor eating habits and the ketogenic diet can do that for you. However, when you adopt the ketogenic diet, you may have to make some adjustments to your workout routines.

“Years of poor eating habits will catch up to you,”
― Jimmy Moore, Keto Clarity: Your Definitive Guide to the Benefits of a Low-Carb, High-Fat Diet

When you start the ketogenic diet, you may not feel great at first. Naturally, this will effect your workouts. You may feel like you are in a fog for the first few weeks. Your brain’s primary fuel source has been glucose, however on the ketogenic diet, it switches over to ketone bodies, created by breaking down fats in the liver. It will take some time to adjust. Fortunately, the mental fog typically passes after a few days. Many people recommend skipping workouts that require quick reactions to stay safe during this transition period such as riding your bike on the road with cars. You can continue doing what you are doing, but trying a new workout as you are adjusting to the ketogenic diet is not a good idea.

It is important to note that on a ketogenic diet, there will be an appetite suppressing effect. You might think you’re not hungry even if you don’t giv eyour body enough energy. It is essential to eat enough food on the ketogenic diet.

A cardio approach to exercise could result in burning more fat. This is one reason that people swear by the ketogenic for weight loss. When you are in ketosis, you aren’t using glycogen as your energy source. Therefore, you burn fat. Glycogen is a substance deposited in muscles and tissues as a reserve of carbohydrates. Running, biking and other cardiovascular exercises comined with a keto diet can help increase fat oxidation, spare glycogen and produce less lactate and use less oxygen. For this reason, you will likely burn more fat during cardio exercise.



The traditional view of weight loss was simple – eat less and do more cardio. However, that is unsustainable. You must get energy in order to exercise. What you eat really does matter. Therefore, pay attention to the quality food on the ketogenic diet and ensure that you are meeting your fat macronutrient ratios on a ketogenic diet.

Exercise has many benefits for your health. It is great for your heart, builds muscle and keeps you lean and toned. Exercise also strengthens the bones. Exercise can completely fit into your routine while you are eating for ketosis. You simply need to keep in mind a few considerations.



The type of exercise that you select will determine the your nutritional needs. Different types of exercise will have different nutritional demands. Workouts are divided into four different types – aerobic, anaerobic, flexibility and stability.

Exercise in Ketosis

Image Source: Perfect Keto

Aerobic exercise is commonly known as cardio exercise. Aerobic exercise is any type of exercise that lasts longer that three minutes. Lower intensity, steady-state cardio is fat burning. This makes it very friendly for the ketogenic dieter.

Anaerobic exercise is characterized by shorter bursts of energy. These exercises include weight training, or high-intensity interval training. Carbohydrates are a primary fuel for anaerobic exercise. Therefore, fat alone can’t provide enough energy for this type of workout. Your performance may be impacted during the transition to the ketogenic diet. Your body will produce glycogen from the protein through a process called gluconeogenesis. You eventually will be able to perform anaerobic exercise.

Flexibility exercises are very helpful for stretching out and lengthening your muscles, supporting joints and improving your range of motion. Yoga and Pilates are examples of flexibility exercises.

Stability exercises include balance exercises and core training. These type of exercises help to improve your alignment, strength muscles and control movement.

During ketosis, your workout intensity matters:

  • During a low intensity aerobic exercise, the body uses fat for its main energy source.
  • During high-intensity aerobic exercise, carbohydrates are the main energy source.

There is a solution to making anaerobic exercises easier to do at the beginning of the diet. It is using a targeted ketogenic diet for exercise.

How to Use a Targeted Ketogenic Diet for Exercise

For more intense exercise during a ketogenic diet, it is wise to adjust your keto diet to fit your carb needs for your exercise. Simply sticking to the standard ketogenic diet may not work for you.

There is a good rule of thumb to eat 15-30 grams of fast acting carbohydrates, such as fruit, within 30 minutes prior to your workout and 30 minutes after your workout. This ensures that you provide your muscles with a proper amount of glycogen to perform the training and be able to recover. It allows the carbs to be used exactly for this purpose and to preven any risk of leaving ketosis.



A standard ketogenic diet is roughly 20-30 grams of net carbohydrates per day. A targeted ketogenic diet is between 20-50 grams or less of net carbs, but these carbs are taken 30 minutes to one hour prior to exercise. It is best for athletes with high-intensity activities. A cyclical ketogenic diet is eating low-carb keto for several days and then eating higher carbs for a few days.

You can test out which ketogenic diet first your lifestyle. Some people report feeling better on more carbohydrates, while others report feeling better without any carbohydrates, such as people who are following a carnivore diet, like Shawn Baker.



The keto-adaptation phase can last for about 2-3 weeks. The great news is that the body will adapt to low carb eating and start to use fat for fuel. Once the adaptation phase is over, exercise performance can increase greatly. Since the body is no longer using the carbohydrates for energy, it turns to the body’s secondary fuel source, fat. This will change how the body uses energy when working out, as the preferred source for muscles, glycogen isn’t present without carbohydrate intake.


Some people view exercise during ketosis as bad for performance, but it does have many benefits.

  • A study of a 3 hour run indicated 2-3 times more fat burn was seen in ultra-endurance athletes who ate low-carb for an average of 20 months compared to those following a high-carb diet.
  • The low-carb group used and replenished the same amount of muscle glycogen as the high-carb group.
  • Being in ketosis may prevent fatigue during longer periods of aerobic exercise.
  • Ketosis helps with blood glucose maintenance during exercise.
  • The power of keto-adaptation helps low-carb dieters perform better in all forms of exercise with less carbs over time.


There are some studies that show the power of ketosis for movement and peak physical performance.

  • Demographic verification of European cultures from the past has demonstrated people were living as mostly hunters, which means they had very little dietary intake of carbs and still functioned without physical hinderance.
  • Before the Inuit diets were altered, their traditional diet was virtually devoid of carbs. They ahd a heavy emphasis on animal foods with no known problems. The Inuits were also hunters.
  • Before the diets of the Inuit people were altered more, their traditional diet was virtually devoid of carbs with a heavy emphasis on animal foods and no known problems. 

Leave a Reply

Your email address will not be published.