Exercising On Keto: Does It Help?

The ketogenic diet is a popular eating plan for those looking to lose weight. It involves eating mostly low-carbohydrate and high-fat foods, depriving the body of glucose, which is its main source of energy. Instead, the body burns fat for fuel. While the keto diet can have weight loss benefits, certain workouts may be more challenging. Low-intensity, steady-state workouts (like jogging or cycling) tend to be the least affected by the diet. High-intensity exercises, on the other hand, can be more difficult for people on a ketogenic diet as they require short, intense bursts of energy, which is derived from carbohydrates.

Some studies have found that the keto diet may improve endurance and fat-burning during exercise, while others have found that it could drain energy levels and negatively affect performance. The impact of the keto diet on athletic performance remains a subject of controversy, and more research is needed to determine its effectiveness in combination with different types of exercise.

Exercise can help you get into ketosis faster

Exercise impacts ketosis by depleting glycogen stores, which is the storage form of glucose from the carbohydrates you eat. Once your glycogen storage gets depleted, your body starts metabolizing fat. As a general rule, longer and more prolonged physical activity degrades muscle glycogen more quickly than mild exercise.

High-intensity exercises such as sprinting or HIIT (High-Intensity Interval Training) will help use up your glucose stores so you can achieve ketosis more quickly. However, it's important to note that a lack of carbohydrates may negatively affect your exercise performance as having high levels of glycogen is necessary for strenuous workouts.

Exercising while in ketosis accelerates weight loss. This is because the longer and harder you work out, the faster your glycogen stores will run out. When combined with a very low-carb diet, which also reduces glycogen, you will take your weight loss to the next level.

Additionally, working out in ketosis leads to greater weight loss by preserving lean muscle mass. The more lean muscle you have, the higher your resting metabolic rate or resting energy expenditure (REE). This means your body burns more calories even when at rest.

If you're looking to build muscle while on keto, strength exercises like weightlifting, squats, push-ups, and other bodyweight workouts are a great idea. For those who prefer low-intensity exercises, jogging, biking, circuit training, or swimming are good options.

Overall, exercise can be a helpful tool to get into ketosis faster and maximize the benefits of the ketogenic diet.

Low-intensity exercises are better suited for keto

The ketogenic diet is a very low-carb, high-fat, moderate-protein diet that can have weight-loss benefits. However, its effect on athletic performance remains a subject of controversy. While some studies have found that it may enhance performance for endurance athletes, others have found that it negatively affects performance in high-intensity exercises.

Here's why low-intensity exercises are better suited for keto:

Low-intensity exercises are less affected by the keto diet

Low-intensity, steady-state workouts like easy jogging, cycling, yoga, and swimming tend to be the least affected by the keto diet. This is because the keto diet changes how your body gets energy, relying on burning fat instead of carbohydrates, which are the main source of energy for high-intensity activities. As a result, the keto diet tends to limit performance during high-intensity workouts.

The keto diet can impair muscle growth

The keto diet may be fine for maintaining muscle mass, but maximizing muscle growth can be challenging. This is because muscle growth requires a good amount of protein, and some versions of the keto diet involve restricting protein intake. Additionally, keto diets are often low in calories, which can make it more difficult to consume enough protein to build muscle mass.

The keto diet may decrease energy levels

The keto diet involves severely restricting carbohydrates, which are the body's main source of energy. Therefore, switching to a keto diet can negatively affect energy levels, especially as your body adapts to using fat for fuel instead of carbs. Some people experience decreased energy levels when they start the keto diet, which gradually increase back to normal over time.

The keto diet may be better for weight loss

A 2018 study found that when overweight adults replaced carbohydrates with fat for five months, their bodies burned approximately 250 more calories per day than those on a high-carb, low-fat diet. This is because fat has more calories per gram than carbs or protein. However, it's important to note that creating a calorie deficit is still necessary for weight loss on the keto diet, as burning fat doesn't always mean fat loss.

Exercise can speed up weight loss in ketosis

Exercise is an important strategy for keeping fit and healthy, and it can also accelerate weight loss for people on the keto diet. Ketosis is a metabolic state in which the body burns fat for fuel instead of glucose. This shift in fuel source leads to weight loss, one of the biggest benefits of ketosis.

Exercise helps deplete glycogen stores, making it easier to enter ketosis. Glycogen is the storage form of glucose derived from dietary carbohydrates. Once glycogen storage is depleted, the body starts metabolising fat. Longer and more intense physical activity tends to deplete muscle glycogen faster than mild exercise.

However, it is important to note that a lack of carbohydrates may negatively impact exercise performance. High levels of glycogen are necessary for strenuous workouts to boost output. This is why exercises that require bursts of energy, such as high-intensity interval training (HIIT), can be more challenging for people on a ketogenic diet.

Exercising while in ketosis accelerates weight loss by depleting glycogen stores and preserving lean muscle mass. The longer and more intense the workout, the faster glycogen stores are used up. Combining exercise with a very low-carb diet, which also reduces glycogen, can further enhance weight loss.

Preserving lean muscle mass through exercise also boosts weight loss. The more lean muscle you have, the higher your resting metabolic rate or resting energy expenditure (REE). This means your body burns more calories even at rest, as muscle tissue is more metabolically active than fat tissue. Resistance training or weightlifting is the most effective type of exercise for building and preserving muscle mass regardless of age.

Types of Exercises to Do While in Ketosis

Low-intensity steady-state (LISS) cardio exercises, such as walking, running, cycling, elliptical training, and swimming, are generally more comfortable and tolerable for people new to the keto diet than higher-intensity workouts. LISS exercises are also more effective than HIIT in reducing total body fat and improving fat distribution. Additionally, low-intensity workouts are easier to recover from and are suitable for people of all fitness levels.

For those looking to build muscle while on keto, strength exercises like weightlifting, squats, push-ups, and other bodyweight workouts are recommended. It is important to consider other factors that influence muscle development, such as protein intake, training load, calorie intake, and recovery.

While intense workouts like burpees, sprints, and mountain climbers can be challenging for beginners, they can be performed while in ketosis by reaching a fat-adapted state. This involves consistently keeping carb intake low (30-50 grams or less per day) for several weeks to optimise fat-burning.

Carbohydrate Consumption While Exercising on Ketosis

The keto diet typically limits carb intake to up to 50 grams per day. However, consuming carbohydrates around exercise sessions can be beneficial. For example, eating 25 grams of carbs 30-60 minutes before a workout and the remaining 25 grams as part of post-workout recovery can be effective. This could include two slices of bread before the workout and a cup of walnuts and hazelnuts with a small amount of berries after the workout.

Very active individuals and professional athletes may be able to consume more carbohydrates while still maintaining ketosis. It is helpful to monitor blood or urine ketone levels using ketone test strips to ensure you remain in ketosis.

Other Tips to Speed Up Weight Loss in Ketosis

In addition to exercise, there are other strategies to enhance weight loss while on the keto diet. Intermittent fasting or minimising snacking between meals can increase weight loss. Choosing zero-carbohydrate snacks like boiled eggs, beef jerky, and canned tuna when feeling hungry can help maintain ketosis.

Sleep habits also impact weight loss. Adequate sleep, aiming for at least seven hours per night, reduces appetite and cravings and may increase motivation to exercise.

Exercise may impair muscle growth on keto

The ketogenic diet is a very low-carb, high-fat, and moderate-protein diet that has been linked to a range of health benefits, including improved blood sugar control and decreased hunger levels. However, its impact on athletic performance remains controversial. While some claim that keto can boost fat burning and enhance endurance, others argue that it could drain energy levels and impair muscle growth.

Impaired Muscle Growth on Keto

The ketogenic diet may be suitable for those looking to maintain muscle mass, but maximizing muscle growth can be challenging. This is because muscle growth requires adequate protein intake, which is necessary for muscle synthesis and tissue repair. Some versions of the keto diet may involve restricting protein intake, making it difficult to consume enough protein to support muscle growth. Additionally, keto diets are often low in calories, which can further hinder muscle growth. Consuming more calories than you expend is crucial for maximizing muscle growth.

High-Intensity Exercise and Keto

High-intensity exercises, such as strength training, sprinting, and other sports, rely on short bursts of intense energy. Typically, carbohydrates fuel these activities as they are stored in muscle cells as muscle glycogen, providing an immediate fuel source. However, on a keto diet, the body prioritizes burning fat for energy instead of carbohydrates, which can lead to reduced performance during high-intensity workouts.

Studies on Keto and Muscle Growth

Some studies have found that the keto diet may impair muscle growth. For example, one study showed that keto dieters experienced a decrease in lean body mass, while another study found that keto dieters had a harder time completing high-intensity exercises. Additionally, research suggests that increased levels of ketones in the blood can lead to increased fatigue and decreased desire to exercise, further impacting muscle growth.

Strategies for Keto and Exercise

For those on a keto diet, it is recommended to focus on low-intensity, steady-state exercises such as jogging, biking, yoga, and swimming. These activities are less affected by the keto diet and can help maximize the potential benefits of keto, such as improved endurance and fat burning. It is also important to closely manage macronutrients before working out and ensure adequate protein intake to support muscle maintenance and growth.

Exercise may decrease energy levels on keto

The ketogenic diet involves a severe restriction of carbohydrates, which are the body's main source of energy. Therefore, switching to a ketogenic diet can negatively impact athletic performance and energy levels, especially as your body initially adapts to using fat for fuel instead of carbohydrates.

The Body Adapts to Using Fat for Fuel

As your body becomes "keto-adapted", it begins to train itself to burn fat for energy instead of carbohydrates. Initially, this process may leave you feeling less energised than usual when it comes to working out.

Research Findings

Research findings suggest that athletes have been successful in increasing their ability to use fat as a fuel source. A small July 2017 study found that athletes on a high-fat diet experienced reduced energy initially, but these levels gradually returned to normal over time. However, the athletes in the study had more difficulty undertaking higher-intensity forms of exercise.

The Keto Diet May Be Better Suited to Low-Intensity Exercise

The keto diet may be better suited for low-intensity, steady-state forms of physical activity than high-intensity bursts of exercise. High-intensity exercise is better fuelled by carbohydrates because it maximises short, intense bursts. As the keto diet focuses on burning fat instead of carbohydrates, it is not as efficient for high-intensity training and can feel very draining.

The Keto Diet May Impair Performance

A study found that the keto diet can impair performance, and so it is not recommended for those training as part of a team or for a specific high-intensity physical activity or sport. During high-intensity workouts, the keto diet can lead to faster exhaustion.

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