Keto Fitness: Does It Really Work?

The ketogenic diet is a low-carb, high-fat diet that puts the body in a state of ketosis, where it burns fat for fuel instead of carbohydrates. While it can have weight loss benefits, some workouts may be more challenging. The keto diet may boost fat burning, but it could also decrease energy levels and impair muscle growth. It is generally recommended that those on the keto diet stick to low-intensity, steady-state activities such as jogging, biking, or yoga. High-intensity exercises like weightlifting or HIIT may be more challenging due to the body's reduced carbohydrate stores, which are necessary for short bursts of energy. Additionally, those on the keto diet should ensure they are consuming enough calories and fat to support their workouts and avoid undereating. Overall, the keto diet may have benefits for fitness, but it is important to be aware of the potential drawbacks and adjust your workouts and diet accordingly.

Keto may boost fat burning

The ketogenic diet is a low-carb, high-fat, and moderate-protein diet. The body enters a metabolic state called ketosis, where it turns fats into ketones, which can supply energy to the brain. Ketogenic diets have been linked to weight loss, improved insulin sensitivity, and blood sugar management.

Evidence for Increased Fat Burning

Some studies have shown that the keto diet may boost fat burning during exercise. For example, a study of competitive race walkers found that athletes on ketogenic diets increased fat burning during training compared to those on a standard diet. Another study of 22 athletes found that switching to a keto diet increased fat burning over four weeks.

Mechanisms for Increased Fat Burning

The keto diet may increase fat burning through several mechanisms:

• Higher protein intake: Ketogenic diets often lead to increased protein intake, which is associated with weight loss.
• Gluconeogenesis: The body converts fat and protein into carbs for fuel, burning additional calories.
• Appetite suppression: Ketogenic diets suppress appetite, leading to reduced calorie intake.
• Improved insulin sensitivity: Ketogenic diets improve insulin sensitivity, enhancing fuel utilization and metabolism.
• Decreased fat storage: Ketogenic diets reduce lipogenesis, the process of converting sugar into fat.
• Increased fat burning at rest and during exercise: Several studies suggest that ketogenic diets may increase fat burning during rest, daily activity, and exercise.

Considerations

It's important to note that the keto diet may not be suitable for everyone. Some people may experience "keto flu," with symptoms like poor energy, increased hunger, and sleep issues. Additionally, long-term adherence to the keto diet can be challenging. While the keto diet may boost fat burning, it's essential to consider individual needs and preferences when choosing a diet plan.

High-intensity exercises may be tougher

The ketogenic diet may not be the best option for those who engage in high-intensity exercises or training. High-intensity exercises are powered mainly by carbohydrates, which the body stores in muscle cells as muscle glycogen. This muscle glycogen serves as an immediate fuel source for intense physical activity. However, the keto diet restricts carbohydrate intake, which means the body burns fat for energy instead of carbohydrates. This alternative fuel source is not as easily burned as carbohydrates, making the process less efficient and potentially impairing performance during high-intensity workouts.

A study by Urbain et al. (2017) found that after six weeks on the keto diet, participants' endurance capacity and peak power decreased. Similarly, a study by Burke et al. (2017) on elite competitive walkers showed that those on keto diets experienced a decline in athletic performance compared to those on a standard diet, despite burning more fat. The keto group also reported that completing the same workouts required greater exertion, and they were less likely to finish the assigned routines.

Additionally, the keto diet may not be ideal for maximising muscle growth. This is because muscle growth requires a significant amount of protein, and some versions of the keto diet may involve restricting protein intake. Furthermore, keto diets tend to be low in calories, making it more challenging to consume enough protein to support muscle growth.

While the keto diet may not complement high-intensity exercises, it is important to note that individual results may vary. Some people may find that they can still perform high-intensity exercises while adhering to the keto diet. It is always a good idea to consult with a healthcare professional or a dietician before making significant dietary changes, especially if you are an athlete or have specific fitness goals.

You may feel less energised initially

When starting the keto diet, it's important to be mindful of how your body is feeling. You may experience a "keto-flu" in the initial stages, with symptoms such as grogginess, stomach upsets, and reduced energy levels. This is because your body is transitioning from burning glucose to burning ketones for energy. As your brain's primary fuel source is glucose, it will take some time to adjust to breaking down fats in the liver. This can result in a mental fog, and you may feel less energised than usual, especially during workouts.

To manage this, it's recommended to stick to your current workout routine and avoid trying new, intense exercises until you've adjusted to the diet. Focus on lower-intensity workouts such as walking, cycling, or yoga, as your body becomes "keto-adapted." This process may take a few days to a couple of weeks, and it's crucial to listen to your body and not push yourself too hard during this transition.

Additionally, make sure you're consuming enough calories and staying hydrated. Drinking water can help reduce muscle cramping, which is a common side effect of the keto diet. It's also important to ensure you're getting adequate rest and recovery between workouts.

While you may feel less energised at the beginning of the keto diet, this effect is usually temporary. As your body adapts to using fat as its primary fuel source, your energy levels will gradually increase, and you'll be able to return to your previous level of athletic performance.

Your body may burn more calories

The keto diet can lead to greater weight loss because it causes the body to burn more calories at rest. This is due to the preservation of lean muscle mass, which has a higher resting metabolic rate or resting energy expenditure (REE). The more lean muscle you possess, the more calories your body burns while at rest.

A 2018 study found that when overweight adults replaced carbohydrates with fat for five months, their bodies were able to burn approximately 250 more calories per day than those who ate high-carbohydrate and low-fat diets. This is because fat is more calorie-dense than carbohydrates, with nine calories per gram compared to four calories per gram for protein or carbohydrates.

However, it's important to remember that the number of calories burned also depends on the type of exercise performed. High-intensity exercises, such as weightlifting or spinning, may be more challenging on a keto diet as the body prefers to use carbohydrates for fuel during these short bursts of intense energy. On the other hand, low-intensity, steady-state exercises like jogging or cycling are less affected by the keto diet as the body can utilise fat as fuel.

While the keto diet may not improve performance in high-intensity exercises, it can enhance endurance in low-intensity exercises. Some studies have shown that being in a metabolic state of ketosis improved physical endurance due to the body's ability to use fat as an alternative source of energy. Additionally, the keto diet may speed up muscle recovery after exercise.

Keto is better for maintaining muscle mass than building it

The ketogenic diet is a very low-carb, high-fat diet that encourages the body to use ketones as fuel instead of glucose, which is the body's preferred source of energy. While the keto diet is popular for weight loss, it has also been linked to various other health benefits, including aiding people with epilepsy, controlling blood sugar levels, and reducing the risk of chronic conditions such as Parkinson's, Alzheimer's, and certain cancers.

One question surrounding the keto diet is whether it can help with exercise performance and building muscle mass. While the keto diet may not be ideal for high-intensity exercises due to the reduced intake of carbohydrates, it can be beneficial for maintaining muscle mass. Here's why:

Maintaining Muscle Mass on Keto

The keto diet can be effective in preserving muscle mass due to the following reasons:

• Fat-Burning: The keto diet trains the body to burn fat for energy instead of carbohydrates. This increased fat burning can help preserve muscle mass as the body uses fat as its primary fuel source.
• Calorie Deficit: To lose weight on the keto diet, creating a calorie deficit is necessary. However, a prolonged calorie deficit can lead to muscle loss. The keto diet's high-fat content can help prevent excessive muscle loss by providing the body with an alternative energy source.
• Protein Intake: The keto diet is often considered a "moderate" protein diet, with 15-20% of total calories coming from protein. This moderate protein intake can help preserve muscle mass by providing essential amino acids for muscle repair and growth.
• Ketone Bodies: The ketogenic diet increases the production of ketone bodies, such as beta-hydroxybutyrate (BHB). BHB has been shown to decrease leucine oxidation and promote protein synthesis, which can help preserve muscle mass.
• Adrenaline Release: Carbohydrate restriction stimulates the release of adrenaline, which prevents muscle protein breakdown. This adrenaline release, combined with ketone bodies, can help maintain muscle mass while losing fat.

Building Muscle Mass on Keto

While the keto diet can be beneficial for maintaining muscle mass, building muscle mass on keto may be more challenging due to the reduced intake of carbohydrates and the potential restriction of protein. Carbohydrates are essential for muscle growth as they promote the release of insulin, an anabolic hormone that helps shuttle nutrients into cells, creating conditions that drive muscle growth. Additionally, building muscle requires a sufficient amount of protein, which can be restricted on the keto diet to maintain ketosis.

However, it is possible to build muscle mass on the keto diet by following specific guidelines:

• Calorie Surplus: To build muscle, consuming more calories than you burn is necessary. On the keto diet, this surplus should come from healthy fats to maintain ketosis.
• Protein Intake: Eating adequate protein is crucial for building muscle. Most studies recommend consuming 0.7-0.9 grams of protein per pound of body weight. However, on the keto diet, it is important not to exceed the moderate protein intake recommendation to avoid being kicked out of ketosis.
• Resistance Training: Incorporating resistance training, such as weightlifting or bodyweight exercises, is essential for building muscle. It is recommended to train at least twice a week for effective muscle growth.
• Supplements: While not required, supplements can help support muscle growth. Protein powder supplements can ensure sufficient protein intake, and creatine monohydrate supplements have been shown to improve gym performance.
• Timing and Distribution of Protein: Spacing out protein intake evenly throughout the day and consuming specific amounts to reach the "leucine threshold" can maximize muscle growth.

In conclusion, while the ketogenic diet may not be ideal for building muscle mass due to the reduced intake of carbohydrates and potential protein restrictions, it can be highly effective for maintaining muscle mass. The increased fat burning, calorie distribution, ketone bodies, and adrenaline release associated with the keto diet can help preserve muscle mass while losing fat. However, to build muscle mass on keto, specific guidelines, such as a calorie surplus, adequate protein intake, resistance training, and proper timing of nutrient intake, should be followed.

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