Personal Trainer Liverpool Is 72 hour fast better than 48?

Is 72 hour fast better than 48?

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Is a 72-Hour Fast Superior to a 48-Hour Fast? Insights from a Personal Trainer

As a personal trainer committed to guiding individuals on their fitness journeys, I frequently encounter questions about various fasting protocols. Among these, the debate between a 72-hour fast and a 48-hour fast is a common dilemma. In this comprehensive exploration, we will dissect the nuances of both approaches, weighing the potential benefits and considerations, to help you make an informed decision based on your health and fitness goals.

Understanding the Fasting Windows:

Before delving into the comparison, let's first understand the basics of these fasting windows.

  1. 48-Hour Fast:

    • In a 48-hour fast, individuals abstain from food for a continuous 48-hour period. This typically involves refraining from eating for two complete days.

  2. 72-Hour Fast:

    • A 72-hour fast extends the period of food abstinence to a total of 72 hours, equivalent to three consecutive days without eating.

Physiological Responses to Fasting:

As a personal trainer, I emphasize the importance of understanding how the body responds to different fasting durations.

  1. Autophagy Activation:

    • Both 48-hour and 72-hour fasts can trigger autophagy, a cellular recycling process that removes damaged cells and supports overall cellular health. Autophagy is linked to various health benefits, including improved longevity and reduced inflammation.

  2. Ketosis and Fat Utilization:

    • Fasting durations beyond 24 hours induce ketosis, where the body shifts to burning fat for energy. Both 48-hour and 72-hour fasts promote fat utilization and can contribute to weight loss.

  3. Hormonal Changes:

    • Prolonged fasting influences hormones such as insulin and growth hormone. Insulin sensitivity improves, and growth hormone levels rise, supporting muscle preservation and fat metabolism.

Factors Influencing the Choice:

Now, let's delve into the factors that may influence whether a 72-hour fast is better than a 48-hour fast.

  1. Goals and Objectives:

    • The choice between a 48-hour and 72-hour fast depends on individual goals. If the aim is primarily weight loss, both durations can be effective. However, if the focus is on maximizing autophagy, some argue that a longer fasting window, such as 72 hours, may provide additional benefits.

  2. Individual Tolerance:

    • Personal tolerance to extended fasting varies. Some individuals find it challenging to sustain a 72-hour fast due to factors like energy levels, work commitments, or lifestyle preferences. In such cases, a 48-hour fast may be more feasible and still yield positive outcomes.

  3. Medical Considerations:

    • Individuals with underlying health conditions or those taking medications should consult with healthcare professionals before attempting extended fasts. The appropriateness of a 72-hour fast versus a 48-hour fast may depend on individual health status and medical advice.

  4. Consistency and Sustainability:

    • Sustainability is key in any fasting protocol. Consistency in adhering to the chosen fasting duration is crucial for long-term success. If a 72-hour fast feels too daunting, starting with a 48-hour fast and gradually progressing may be a more sustainable approach.

Additional Considerations:

  1. Psychological Impact:

    • The psychological aspect of fasting cannot be overlooked. Some individuals may find a 48-hour fast more mentally manageable, promoting a positive mindset and reducing the risk of anxiety or stress associated with a more extended fasting period.

  2. Social and Lifestyle Factors:

    • Considerations such as social events, work commitments, and personal lifestyle play a significant role in choosing the fasting duration. Aligning fasting windows with one's lifestyle enhances adherence and long-term success.

  3. Refeeding and Nutrient Intake:

    • Refeeding after an extended fast is a critical aspect. A 72-hour fast may necessitate a more cautious approach to reintroducing food, emphasizing nutrient-dense options to support the body's needs during the transition back to regular eating.

  4. Metabolic Flexibility:

    • Extended fasting can enhance metabolic flexibility, the body's ability to switch between burning carbohydrates and fats for fuel. Both 48-hour and 72-hour fasts contribute to this adaptation, promoting overall metabolic health.

Guidance for Implementation:

As a personal trainer, I offer guidance for individuals considering either a 48-hour or 72-hour fast:

  1. Prioritize Hydration:

    • Staying hydrated is essential during extended fasts. Consume water, herbal teas, and electrolyte-rich beverages to support overall well-being.

  2. Nutrient-Dense Meals Pre and Post-Fast:

    • Opt for nutrient-dense meals before and after the fast to provide essential vitamins and minerals. Focus on whole foods, lean proteins, and healthy fats.

  3. Listen to Your Body:

    • Pay attention to your body's signals. If you experience extreme fatigue, dizziness, or discomfort, consider adjusting the fasting duration or consulting with healthcare professionals.

  4. Gradual Progression:

    • If new to extended fasting, consider gradually progressing from shorter durations to longer ones. This approach allows the body to adapt more smoothly.


The choice between a 72-hour fast and a 48-hour fast ultimately depends on individual goals, tolerance, and lifestyle. As a personal trainer, I advocate for a personalized approach that aligns with an individual's health and fitness objectives. Both fasting durations offer potential benefits, and experimenting with different protocols can help determine what works best for each person.

Consulting with healthcare professionals and incorporating fasting into a holistic lifestyle approach ensures a balanced and sustainable journey towards optimal well-being. Whether opting for a 48-hour or 72-hour fast, the key lies in consistency, mindfulness, and adapting the fasting protocol to suit individual needs and preferences.

Gain additional insights into intermittent fasting by navigating to 48 Vs 72 Hour Fast: Which Is Better And Why? or by watching the video featured below.

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