Best Time To Work Out On A Keto Diet

The ketogenic diet is a popular choice for those looking to lose weight and improve their health. But what happens when you combine keto and exercise? Does it affect your performance? And will it make avoiding carbs impossible?

Exercising on a keto diet can be challenging, especially for high-intensity workouts like HIIT, sprinting, or weightlifting. This is because your body is using fat for fuel instead of carbohydrates, and fat is not as easily burned for energy. As a result, you may feel more tired and sluggish during your workouts, and your performance may be impacted.

However, low-intensity, steady-state workouts like jogging, cycling, or yoga tend to be less affected by the keto diet. This is because lower-intensity exercises burn more fat as fuel, which is what the body is using on a keto diet.

So, if you're following a keto diet, it's important to adjust your workouts accordingly. Focus on low-to-moderate-intensity exercises and give your body time to adapt to using fat for fuel. You may also need to be mindful of your protein and fat intake to ensure you're getting enough energy and supporting muscle recovery.

Overall, while the keto diet may not be ideal for high-intensity exercises, it can be compatible with a well-planned exercise routine that takes into account your body's changing energy sources.

High-intensity exercises may be more challenging

High-intensity exercises, such as HIIT, sprinting, or weightlifting, are more challenging on the keto diet. This is because they require quick bursts of energy, which the body usually gets from carbohydrates. On a keto diet, the body uses fat as fuel instead of carbohydrates, and fat is not as readily available to the muscles for energy. As a result, people on a keto diet may experience reduced endurance and hit a wall earlier in their workout.

The keto diet is not ideal for improving physical performance in high-intensity exercises. A study from February 2017 found that participants' performance in endurance capacity and peak power dropped after following a ketogenic diet for six weeks. Another study of elite competitive walkers showed that athletes on ketogenic diets burned more fat during training but also experienced worse athletic performance and increased exertion.

If you are doing high-intensity exercises, it is important to be cautious and understand your body's limitations. Pushing yourself too hard can lead to potential injuries. It may be beneficial to start with low-to-moderate-intensity exercises and gradually increase the intensity as you adjust to the keto diet.

Additionally, it is important to ensure proper fueling and hydration when exercising on a keto diet. Eating enough calories and staying hydrated can help support your energy levels and performance during high-intensity exercises.

Low-intensity exercises are less affected

The ketogenic diet can be challenging to navigate when it comes to working out, especially for high-intensity exercises. However, low-intensity exercises are generally less affected by this diet and can even be beneficial.

Low-intensity, steady-state exercises like jogging, cycling, yoga, and swimming are recommended for those on the keto diet. These types of exercises are less demanding on the body and can help improve endurance. The body can more easily use fat as its main energy source during these workouts, as it has time to adapt and break down fats efficiently.

When beginning the keto diet, it is normal to experience fatigue and reduced performance, even in low-intensity exercises. This is because the body is adjusting to using fat instead of carbohydrates for fuel. However, as the body becomes keto-adapted, these side effects usually subside, and energy levels return to normal.

It is important to listen to your body and not push yourself too hard, especially during the initial adjustment period. Start with low-intensity exercises and gradually increase the intensity and duration of your workouts as you become more comfortable. This will help you avoid injury and health issues.

Additionally, proper nutrition and hydration are crucial for optimal performance on the keto diet. Make sure to eat enough protein, maintain adequate electrolyte levels, and drink plenty of water to support your body's needs during exercise.

Overall, combining the keto diet with low-intensity exercises can be a safe and effective way to improve your health and fitness while still enjoying the benefits of ketosis.

You might feel more sluggish during workouts

It's important to note that the keto diet is a significant change for your body, and it will take time to adjust. During this transition, you may experience what is commonly known as the "keto flu," which can include symptoms such as fatigue, nausea, and headaches. This is often due to the shift in metabolism as your body switches from burning carbs to burning fat for fuel. The good news is that this usually passes within the first week.

Your body is adjusting to a new fuel source

On a typical diet, your body relies on carbohydrates for quick energy bursts during high-intensity workouts. However, when you're on the keto diet, your body uses fat as its main fuel source, which is not as readily available for energy. This change can make high-intensity exercises more challenging and leave you feeling sluggish.

Electrolyte imbalances and dehydration

The keto diet is a low-carb diet, and when you reduce your carb intake, your body excretes more water and electrolytes. This can lead to dehydration and electrolyte imbalances, resulting in symptoms such as fatigue, brain fog, and muscle cramps. To counteract this, ensure you're staying hydrated and consider taking electrolyte supplements.

Calorie deficit and undereating

The keto diet can suppress your appetite, making it easier to stay in a calorie deficit. While this is great for weight loss, undereating can lead to a decrease in energy levels and even a crash in your metabolism. Make sure you're consuming enough calories and healthy fats to fuel your body, especially if you're also working out.

Quality of food

Not all keto diets are created equal. Eating unhealthy, processed foods that fit the keto macros but lack essential nutrients can contribute to vitamin and mineral deficiencies, affecting your energy levels. Opt for high-quality, nutritious foods, including fibre-rich, low-carb vegetables and healthy fats.

Stress

Adapting to the keto diet can be a significant change for your body, and it may temporarily increase stress levels, leading to physical and psychological symptoms such as fatigue, difficulty sleeping, and hormonal imbalances.

Remember, it's important to listen to your body and adjust your workouts accordingly during the transition to the keto diet. Start with low-to-moderate intensity exercises and gradually increase the intensity as you feel more energised.

Avoid new workouts in the first few weeks

When starting the keto diet, it's important to remember that your body is going through a significant adjustment period, especially in the first few weeks. Here are some reasons why you should avoid new workouts during this initial phase:

• Keto Flu: During the first two to four weeks of the keto diet, it's common to experience symptoms like brain fog, nausea, fatigue, and headaches. This is often referred to as the "keto flu." Your body is adjusting to burning fat for energy instead of carbohydrates, which can result in these flu-like symptoms. It's best to give your body time to adapt and recover during this transition.
• Energy Levels: The keto diet can affect your energy levels, especially in the beginning. Your body is learning to use fat as its primary fuel source, which takes time. As a result, you may feel more sluggish and tired during this adjustment period. Introducing new, intense workouts may be challenging and increase the risk of injury.
• Metabolic Adjustment: Your body needs time to adjust to a new metabolic state called ketosis, where it burns ketones derived from dietary or stored body fat. This process can take a few days to a couple of weeks. During this time, your body is learning to efficiently use fat for fuel, and high-intensity workouts may be more difficult to perform.
• Electrolyte Imbalances: The keto diet can cause electrolyte imbalances, particularly in the initial stages. This is because the body tends to flush out a lot of water during the transition to ketosis, which can deplete electrolytes. As a result, you may feel more fatigued, and your muscles may not function optimally. It's important to allow your body to restore its electrolyte balance before engaging in new, intense workouts.
• Performance Impact: High-intensity exercises that require short, intense bursts of energy, such as sprinting or weightlifting, may be more challenging during the initial weeks of the keto diet. This is because your body is still adapting to using fat as fuel instead of carbohydrates, and fat is not as readily available for muscle energy. Starting a new, intense workout routine during this time may be difficult and frustrating.
• Nutritional Adjustment: Starting a new diet and a new workout routine simultaneously can be challenging. The keto diet often requires a significant shift in your eating habits, and it's important to ensure you're meeting your nutritional needs. Introducing a new workout routine can further complicate this process. It's advisable to give yourself time to adjust to the keto diet and plan your meals accordingly before adding new physical demands.

In summary, avoiding new workouts in the first few weeks of the keto diet is advisable to allow your body to adjust to this significant change in fuel sources. Give yourself time to recover from the keto flu, stabilize your energy levels, and adapt to the new metabolic state. Focus on lower-intensity exercises during this period, and once your body has adjusted, you can gradually introduce new and more intense workouts. Remember to listen to your body and adjust your exercise routine accordingly.

Make sure you're eating enough

When starting a keto diet, it's common to feel foggy, nauseous, and fatigued during the first two to four weeks. These symptoms are largely caused by changes in your metabolism as your body adjusts to burning fat for energy instead of carbohydrates. You may also experience electrolyte dips, as the keto diet typically flushes a lot of water out of your body at first. As a result, you might not feel like exercising at first.

It's important to make sure you're eating enough during this adjustment period. If you're in too much of a caloric deficit, your body will kick into starvation mode, which can lead to muscle breakdown and increased risk of injury. Planning your meals in advance can help ensure you're getting enough calories and nutrients.

Clinical nutrition coach Ariane Hundt recommends focusing on workouts that balance appetite, cravings, and energy during the first week or two, such as weightlifting two to three times a week followed by low-intensity cardio. Lower-intensity cardio burns more fat as fuel, while higher-intensity workouts burn more sugar as fuel. This makes lower-intensity workouts a better option when you're starting a keto diet.

To ensure you're eating enough, aim to consume between 1.0 and 1.2g of protein per pound of lean body mass daily. You can meet your remaining calorie needs with fat and carbs, depending on your diet and workout needs. Remember, eating the right amount of calories and protein is crucial when you want to improve your body composition.

In addition to eating enough, make sure you're staying properly hydrated. Even a small amount of water loss can impair physical performance and cognitive function. Dehydration can also slow down muscle protein synthesis, so it's important to drink enough water before, during, and after your workouts.

Sample Pre-Workout Meals

• Keto coffee smoothies: Blend coffee with MCT oil for a creamy, energizing drink. MCTs are easily digested and converted into ketones, providing a quick and efficient energy source for your muscles and brain.
• Protein shakes: Use a high-quality plant-based or whey protein powder, unsweetened almond or coconut milk, nut butter, collagen, avocado, low-carb veggies, and berries.
• Full-fat cottage cheese or Greek yogurt: Top with homemade granola, nuts, seeds, unsweetened coconut flakes, or berries.
• Fatty fish: Tuna, salmon, and sardines are rich in omega-3 fatty acids, which can help reduce inflammation and speed up recovery.
• Carnivore charcuterie: Turkey, chicken, or beef roll-ups, jerky, or canned fatty fish are convenient options for a quick pre-workout snack.

Frequently asked questions