Is It Safe To Workout While Fasting?

Summary

In this informative video, Dr. Ekberg, a holistic doctor and former Olympic decathlete, addresses the safety and implications of exercising during fasting. He debunks common myths about energy and nutrition, explaining that energy for exercise comes from stored glycogen and fats, not from recent meals. The video explores how the body adapts to using fat for fuel during fasting, the importance of being 'fat adapted' for optimal performance, and offers guidance on the type and intensity of exercise suitable during different fasting states.

Takeaways

• 🏃‍♂️ It is generally safe to exercise while fasting, but the safety and effectiveness depend on the type, duration of exercise, and the state of your metabolism.
• 🚫 Common myths about needing to eat frequently for energy and consuming protein immediately after a workout are debunked; the body utilizes nutrient stores rather than immediate food intake for energy.
• ⏳ The digestion process takes 2 to 5 hours in the stomach and 4 to 12 hours for nutrient absorption in the small intestine, indicating that the energy for exercise does not come from the last meal.
• 🍇 Eating fruit provides a small amount of glucose, but most whole foods take longer to break down and absorb, emphasizing that immediate post-meal energy comes from hormonal responses, not nutrient use.
• 💪 The body has various energy stores like glycogen, fat, and protein that can last from hours to years, showing that humans are not prone to quickly running out of energy.
• 🔄 The body can adapt to use fat as a primary energy source during fasting, especially after being trained through a ketogenic diet or similar practices.
• 🏋️‍♀️ For weight lifting, the body might break down muscle tissue to create energy, but this can be beneficial if followed by proper nutrition to repair and strengthen muscles.
• 🚶‍♂️ Aerobic exercises can be performed effectively during fasting, especially by those who are fat-adapted, relying primarily on body fat for energy.
• 🏃‍♀️ Intense or anaerobic exercises require more glycogen, which might be limiting during fasting, especially for those who are not fat-adapted and have lower glycogen stores.
• 🕒 After a prolonged fast of 72 hours or more, the body transitions to using more fat for energy regardless of initial carb dependency, although the adaptation process might cause discomfort.
• 🥗 The importance of understanding your body's metabolic state and adjusting exercise intensity and nutrition accordingly is highlighted for optimal health and performance.

Q & A

Is it safe to exercise while fasting according to Dr. Ekberg?

Yes, it is generally safe to exercise while fasting, but it depends on the type, duration of the exercise, the duration of the fast, and whether your body is fat adapted or carb dependent.

What happens in the body during fasting or intermittent fasting?

During fasting, the body transitions from using glucose for energy to utilizing stored glycogen and body fat. The body becomes more efficient at burning fat for fuel, especially if it is fat adapted.

Where does the energy for exercise come from if not from the most recent meal?

The energy for exercise comes from nutrient pools in the body, including glycogen stored in the muscles and liver, and body fat. These stores can last for hours to months, depending on the individual's body composition and adaptation to fasting.

What is the role of glycogen in the body during exercise?

Glycogen is a form of stored glucose in the muscles and liver. During exercise, especially high-intensity or anaerobic exercise, the body breaks down glycogen to provide quick energy.

How does the body feel energized after eating if it takes time to absorb nutrients?

The feeling of energy after eating is due to the stimulation of hormones and the body's expectancy of being able to utilize the food. The body starts breaking down glycogen to raise blood sugar, creating a feeling of satisfaction and energy.

What is the difference between being fat adapted and carb dependent during exercise?

Fat-adapted individuals primarily use body fat for energy during exercise, while carb-dependent individuals rely more on glycogen. Fat adaptation allows for longer exercise durations without needing to replenish glycogen stores.

Why might someone feel weak during anaerobic exercise if they are carb dependent and have been fasting?

Carb-dependent individuals may feel weak during anaerobic exercise while fasting because their glycogen stores are low. As the body cannot quickly replenish these stores without food intake, they may experience reduced energy and performance.

How does weight lifting affect muscle repair and growth hormone production?

Weight lifting causes micro tears in the muscles, which the body repairs, leading to stronger muscles. Fasting and stress from exercise stimulate the body to produce more growth hormone, aiding in muscle repair and growth.

What should be considered before exercising after a prolonged fast of 72 hours or more?

Before exercising after a prolonged fast, one should consider their body's adaptation to fat as a fuel source, the intensity and duration of the exercise, and the need to replenish nutrients, especially protein, after the workout to support muscle repair.

Why is it important to replenish protein after a workout while fasting?

Replenishing protein after a workout is crucial to provide the body with the necessary nutrients to repair and rebuild muscle tissue, especially during fasting when the body is in a state of autophagy and trying to conserve protein.

What is the impact of exercise on the body during a transition from carb dependency to fat adaptation?

During the transition from carb dependency to fat adaptation, the body may struggle to efficiently use fat for fuel, leading to feelings of lousy performance and energy levels during exercise. It is important to ease into exercise during this period and listen to the body's signals.