Keto and Exercise: What You Need to Know

The Keto diet has become very popular in recent years as athletes and celebrities hop on the Keto bandwagon and rave about its results. They’re pumped about the Keto diet for a reason. It allows you to burn more fat and calories all while improving your cardiovascular health and decreasing sugar highs and lows. The Keto diet sounds like it pairs perfectly with exercise; however, there are a few things you need to know before you strap on your running shoes. The following article will go over the most commonly asked questions about exercise on the Keto diet so that you can achieve the results that you desire while staying safe.

How does exercise affect Keto?

Exercise affects Keto in a variety of ways. It helps you to lose weight and sculpt your body quite quickly. It increases the amount of fat you lose and it can help you build muscle as well. Exercise can even change how many carbs your body can tolerate before you’re kicked out of ketosis.

However, exercise might also change what types of exercise you’re able to do. If you’re used to performing at a high level of athletic ability then you might find that Keto limits this. Higher intensity exercise relies on glycogen to fuel you through tough workouts. The Keto diet restricts glucose and you might not have enough energy to perform at your best.

What types of exercise are best on Keto?

When you’re just starting the Keto diet you might want to kick your body into ketosis as quickly as possible. In order to do this, you can use exercise as a tool to deplete your glycogen resources. The first day of your Ketoyou should try to do a high-intensity workout for roughly an hour in order to burn up your body’s stored glucose. With this glucose out of your system, it will be much easier to switch to burning ketones as fuel.

After that first day, you should only do low to moderate activities such as walking, jogging, biking, yoga and dancing. If you can’t carry on a conversation while you’re exercising you’re going too hard and you should scale back. High-intensity exercise is great for getting your body into ketosis because it burns through glycogen. Now that there’s very little glucose being added to your body there is no way to continue your high-intensity workouts. You just don’t have the fuel for them.

Instead, focus on moderate exercise. Move your body for a half-hour every day to accelerate your fat and calorie burn. Cardiovascular activities that get your heart pumping are especially good at helping you burn calories on the Keto diet. Low and moderate levels of exercise don’t require glucose. Instead, they’ll force your body to use stored fat as fuel in the form of ketones. This burns through your fat, helping you to burn calories and lose weight.

Can I eat more carbs if I’m exercising on Keto?

This is a complicated question. Everyone has a different level of carbohydrates that their body can ingest without it kicking them out of ketosis. This number of carbs can even change on a daily basis. The longer you do the Keto diet, the better your body will become at producing Ketones and the more carbohydrates you’ll be able to eat. However, if you’re just starting out you should stick to a strict Keto diet where you consume no more than 20-25g of net carbs daily for at least the first 3-6 months.

Exercise can also change how your body responds to carbohydrates. When you do moderate levels of exercise such as walking, jogging or dancing you can begin to eat higher numbers of carbs per day while still producing ketones. However, this differs from person to person and the only real way to test how exercise is impacting your ketosis is by trail and error.

Purchase some urine test strips and test your ketone levels after you’ve been exercising and sticking to your 20-25g net carb limit for several months. Gradually increase the number of carbs you consume and test for ketones as you do so. This will allow you to see your body’s own individual carb threshold and how it changes with exercise.

If you’re interested in higher intensity exercise or if you’re a high-performance athlete there are a few modifications that can be made to the Keto diet in order to increase your carb limits.

Targeted Ketogenic Diet

The Targeted Ketogenic Diet is designed for people who want to do high-intensity workouts. It allows you to eat carbs 30-60minutes before you exercise to increase your glucose levels so that your body has the glycogen it requires to sustain you throughout your workout. This will stop your body from producing ketones and take you out of ketosis; however, it’s a short term break and it shouldn’t affect your Keto diet and the results that you achieve.

Cyclical Ketogenic Diet

The Cyclical Ketogenic Diet is another variation of the Keto diet that was designed for high-intensity exercise and athletes in mind. On Cyclical Keto you eat your normal 20-25g of net carbs daily for 5 or 6 days out of the week. Then you have a day of higher carb intake on 1 or 2 days. On these 1 -2 days of higher carb levels, you essentially restock your body’s carb levels so that high-intensity exercise is possible. However, a note of caution. If you’re not interested in higher levels of exercise this is not the diet for you as it will prevent a lot of the benefits that you can see from the regular Keto diet.

Won’t I be too tired to exercise on Keto?

If you’re feeling tired and draggy after exercising or you just don’t feel like you have enough energy to even begin the workout then you need to make a few adjustments to your diet and exercise. The Keto diet should actually boost your energy levels if it’s done correctly. The highs and lows that you’d normally experience from carbs will disappear and your energy levels should become steady.

However, in the first few weeks of Keto you probably will feel tired and draggy. You might even develop what’s known as the “Keto flu” which is where you feel flu symptoms such as headache, upset stomach and muscle aches as your body adjusts to not having carbohydrates. This is not the time to begin a rigorous exercise program. In fact, you should avoid all but the lightest of exercise and give your body a break so that it can adjust to using ketones as fuel.

If you’re past the two-week mark and you’ve started exercising and you feel weak, dizzy or tired then you might need to take a look at your carb needs and the level of exercise you’re doing. Not everyone is suited for a super low carb diet such as Keto. You might need to talk to your doctor to see if you need to increase your carb levels in order to feel more energetic so that you can exercise.

Your exercise might also be part of your problem. There are some levels of exercise that are just too intense to do on the Keto diet such as high-intensity exercise like HIIT workouts. If you’re feeling tired try scaling back the intensity of your exercise and see if that helps.

Will I have to make any changes to my Keto diet when I exercise?

The short answer is, yes. The Keto diet naturally eliminates calories and it can be easy to restrict your calories to an unhealthy level if you’re not paying attention. One of the side-effects of Keto, and it’s often a welcome one, is the fact that you don’t feel as hungry on the Keto diet. This allows you to eat less and burn more calories. However, if you’re exercising it can actually be a problem as you need to eat enough calories to sustain your body’s energy levels during your workouts.

You might need to watch your fat content as well. It’s vitally important to eat en0ough fat while on the Keto diet to replace the carbs that your body has lost. Without fat as fuel you won’t be able to keep exercising and you’ll feel dizzy, faint and exhausted.

In order to avoid these potential pitfalls be sure to track your calories when you begin a new exercise program. You can’t always rely on your body’s hunger signals while on Keto to make sure that you’re getting enough nutrients. You might find that you have to increase the number of calories you consume. Don’t worry, this won’t lead to weight gain. Exercise and Keto are an amazing team for weight loss but you have to eat enough calories to give your body fuel for the workouts you’re putting it through. Be sure that the calories you’re getting are high in healthy fats. If you feel tired try increasing your healthy fats before you change your protein levels and see if this makes a difference.

Is it possible to lose weight and gain muscle on Keto?

Yes, absolutely! It can be more challenging to gain muscle on the Keto diet than on a higher carb diet; however, it is possible. Carbohydrates are used in the process to build muscle because they’re a quick form of energy and it’s easy for your body to use them. However, fat is a more challenging type of macronutrient to turn into fuel. It’s not as efficient as carbohydrates at helping you create muscle, but it is possible.

When it comes to weight loss, when you combine low to moderate levels of exercise you’ll find that your weight loss efforts are rewarded. These forms of exercise burn fat more readily than high impact exercise which relies on glucose. In order to see weight loss results just be sure to eat enough fat and calories to fuel your body and try not to overdo the exercise.


Exercise and the Keto diet can be a great team when they’re both properly used. Everything requires balance and exercise is no different. If you follow the above tips you’ll find yourself less tired and you’ll see the weight loss results that you want while sticking to your Keto diet in a healthy manner.

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