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To Fast or Not to Fast???

The topic of intermittent fasting is gaining popularity at a rapid pace and it seems like you can't avoid it whether you're on social media, the news or talking to your buddies at the gym. Whether or not to implement it into your routine is something that gets brought up frequently here at Thrive HQ. Intermittent fasting (IF) has gained popularity not only for weight management but also for its potential benefits on athletic performance. Among the various IF protocols, the 5:2 fast, continuous energy restriction, and alternate day fasting have garnered attention for athletes seeking to enhance their endurance, strength, and overall fitness levels. In this blog, we'll delve into the nuances of these IF methods, drawing insights from recent research studies and expert opinions.

  1. Understanding Intermittent Fasting: Intermittent fasting involves alternating periods of eating and fasting, which can range from daily time-restricted feeding (i.e. eating for 8 hours per day and shutting of for 16 hours per day) to more extended fasting windows. The rationale behind IF lies in its ability to induce metabolic adaptations that optimize energy utilization and promote cellular repair mechanisms.

  2. The 5:2 Fast: The 5:2 fast entails consuming a normal diet for five days of the week and restricting calorie intake to 500-600 calories on the remaining two non-consecutive days. Research, such as the study by Harvie et al. (link to the study), suggests that the 5:2 fast may offer metabolic benefits such as improved insulin sensitivity and reduced inflammation, which are crucial for athletes aiming to optimize their performance.

  3. Continuous Energy Restriction: Continuous energy restriction involves maintaining a consistent calorie deficit (typically around 20% total caloric intake) over an extended period, typically weeks to months. While not strictly an intermittent fasting protocol, it shares similarities in its focus on calorie restriction. A recent study by Keenan et al (link to the study) highlights the potential of continuous energy restriction versus the 5:2 intermittent fasting protocol to promote fat loss while preserving lean muscle mass, which is essential for athletes striving to achieve their performance goals.

  4. Alternate Day Fasting: Alternate day fasting alternates between fasting days, where little to no calories are consumed, and feeding days, where regular eating is permitted. This approach has been studied extensively in the context of weight loss and metabolic health. However, its application in athletic settings is less explored. The review by Tinsley and La Bounty provides insights into the effects of alternate day fasting on athletic performance, suggesting that while it may offer benefits such as improved fat oxidation and metabolic flexibility, individualized approaches are necessary to mitigate potential performance decrements.

  5. Considerations for Athletes: While intermittent fasting is safe for athletes and does not appear to have any significant effect, every individual is different and you should listen to what your body is telling you. When implementing intermittent fasting protocols, athletes should consider various factors such as training timing, nutrient timing, and individual metabolic demands. It's crucial to tailor IF strategies to align with training goals, sport-specific requirements, and overall dietary habits. Consulting with a sports nutritionist or dietitian can help athletes develop personalized IF plans that optimize performance while ensuring adequate nutrient intake and recovery.

  6. Comparison: Across a broad range of studies, there is nothing to suggest that any intermittent fasting protocol is superior to just continuous energy restriction but they can be viable alternatives. Both Levy and Chu demonstrated all various intermittent fasting protocols had NO EFFECT on athletic performance. Keenan et al. demonstrated that there was no difference in body composition or strength when intermittent fasting was compared with continuous energy restriction. Finally, in this meta analysis they demonstrated that alternate day fasting produced the best results in regard to fasting and weight loss but that wasn't any different than those that just reduced their caloric intake. What does that mean? The most important thing is to find something that works for you, your lifestyle, your training regimen and something that is SUSTAINABLE.

What do we recommend: start with the basics. Work on making sure you're getting enough PROTEIN FIRST, work on the QUALITY of your food, and your EATING HABITS (ex: how quickly you eat, being mindful of what you eat/where you eat, only eating until you're satisfied) before you start to try to implement any calorie restrictive protocol. The "secret sauce" to improving how you feel and your athletic performance is NOT trendy intermittent fasting but rather it is rooted in small actions done consistently.

At Thrive HQ we do offer FREE nutrition audits as a part of our proven approach, if you're looking to gain more insights on how your nutrition may be affecting your overall fitness please reach out to us!

Thanks for reading!

Dr. Greg

DISCLAIMER: This article is geared towards the general active population. There are certain medical conditions (i.e. diabetes) where certain intermittent fasting protocols can be very beneficial for decreasing or reversing various chronic diseases. Additionally there are certain medical conditions where IF is not appropriate. If you're looking for more medical nutrition guidance please consult with a registered dietician. Additionally, we do not claim to be registered dietitians or nutritionists. This blog is simply a review of relevant literature and our experience in working with clients with a focus on wellness and fitness.

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