The Decision to Exercise While Fasting

The decision to exercise while fasting depends on various factors, including your goals, individual preferences, and overall health. Here are some considerations to help you make an informed choice:

Type of Fasting:

Intermittent Fasting[1]:

If you’re practicing intermittent fasting, which involves cycling between periods of eating and fasting, you can generally engage in light to moderate exercises during fasting hours. Many people find this approach manageable and even beneficial for weight management and energy levels.

Extended Fasting:

If you’re undertaking an extended fast (24 hours or more), It is advisable to refrain from engaging in intense exercise until you have become accustomed to this type of fasting. Extended fasting significantly reduces your calorie intake, which might affect your energy levels and performance during rigorous workouts.

However, please note that avoiding intense exercise does not equate to avoiding exercise altogether. The key focus here is to establish a strong connection with your body’s cues and responses.

Exercise Intensity:

Light to Moderate Exercise:

Low to moderate-intensity activities such as walking, yoga, stretching, and gentle cardio can often be performed during fasting hours without significant negative effects. These activities may even help boost metabolism and enhance fat burning.

High-Intensity Exercise[2]:

High-intensity interval training (HIIT) or intense weightlifting might be more challenging while fasting, especially if your energy levels are low. This will improve as you become accustomed to fasting. It is important to remember that staying hydrated is essential, especially when fasting and exercising. Ensure you drink enough water before, during, and after exercise to prevent dehydration.

Individual Tolerance:

Listen to your body and practice distinguishing emotional responses from physical cues. While some individuals may feel energized and focused during fasting and can exercise comfortably, others may encounter sensations like dizziness, fatigue, or discomfort, particularly in the initial stages. Don’t be disheartened by this; instead, employ a trial-and-error approach. Be attuned to your body’s reactions and adapt your exercise routine accordingly.[3]

Goals:

Exercising while fasting may aid weight loss by further increasing calorie expenditure during fasting periods. However, ensure you’re getting enough nutrients and calories to support your body’s needs outside of the fasting period. If your goal is muscle gain, intense exercise and adequate protein intake are important. In this case, scheduling workouts around eating windows might be more effective.[4]

Timing:

If you’re following an intermittent fasting regimen, it’s advisable to schedule your workouts during the eating window when you have access to nutrients and energy. Fasting could potentially affect the body’s recovery processes, so it’s important to be aware of your body’s post-workout nutritional needs if you decide to exercise while fasting.

Please keep in mind that the articles from the SWEET Institute are intended for educational purposes to empower clinicians. Consulting with your doctor or having your clients consult with their healthcare provider before engaging in exercise while fasting is essential, especially if there are underlying health conditions involved. This precautionary step is crucial for ensuring safety and well-being.

In Summary:

Light to moderate exercise is generally well-tolerated during fasting, especially in the context of intermittent fasting. However, high-intensity workouts might be better suited for eating windows, or you could opt for less intense activities during fasting periods. As with any health-related decision, it’s important to listen to your body, prioritize hydration, and tailor your approach to your individual needs and goals. Consulting with your healthcare professional or a fitness expert can provide personalized guidance.

What’s Next:

1. Stay tuned for upcoming articles in this series, which will delve deeper into the realm of nutrition and its profound impact on well-being.
2. Keep expanding your knowledge on the pivotal role of nutrition in overall health and wellness by staying abreast of the latest research and recommendations.
3. Foster ongoing, open dialogues with your clients about nutrition. Seek to understand potential barriers they face and assist them in overcoming obstacles to cultivating optimal eating habits.

We recognize that instigating habit change can be a formidable undertaking, but motivation can be a potent catalyst when nurtured alongside our patients through the various stages of transformation. As clinicians, fostering awareness, understanding, insight, and expertise in nutrition is instrumental in inspiring positive metamorphoses. This article series aspires to equip you with the essential tools, enabling you to empower both yourself and your patients and clients on their process toward optimal well-being.

As we anticipate our next article, let us continue to master the art of exploration and healing through the transformative power of nutrition.

[1] Arora, Niraj, et al. “Intermittent fasting with ketogenic diet: A combination approach for management of chronic diseases.” Clinical Nutrition ESPEN 54 (2023): 166-174.

[2] Batitucci, Gabriela, et al. “Impact of intermittent fasting combined with high-intensity interval training on body composition, metabolic biomarkers, and physical fitness in women with obesity.” Frontiers in nutrition 9 (2022): 884305.

[3] M. Correia, Joana, et al. “Effects of intermittent fasting on specific exercise performance outcomes: a systematic review including meta-analysis.” Nutrients 12.5 (2020): 1390.

[4] Haupt, Sandra, et al. “Eat, train, sleep—retreat? Hormonal interactions of intermittent fasting, exercise and circadian rhythm.” Biomolecules 11.4 (2021): 516.