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Fasted Workouts Can Make You Shred Faster. But This Scientist Thinks “Sleep Low” is Even Better

 Written by 

Julien Raby

 Last updated on 

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Want to burn fat faster during your workouts? Fasted training could be the answer, but it’s not a magic bullet. 

This controversial strategy has its pros and cons – and science has a lot to say on the topic. 

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In his new video, exercise and nutrition scientist Goar from Wod-Science breaks down the benefits and limitations of training on an empty stomach. 

Discover how fasted training could impact your muscle development and performance, and learn about innovative approaches that might just unlock peak results.

Muscle Adaptation vs. Performance

Goar’s primary assertion is that while fasted training can prime muscles to burn fat more effectively, it doesn’t necessarily enhance performance. 

This distinction is crucial for athletes considering fasted workouts as a strategy to boost competitive edge.

Enhanced Fat Utilization: The Scientific Perspective

Fasted training increases the muscles’ capacity to utilize fat by enhancing the biochemical pathways involved in fat metabolism. 

Goar refers to several studies, including a pivotal 2013 study by Bartlett et al., which demonstrated that low glycogen levels lead to significant increases in markers of mitochondrial biogenesis. 

These markers indicate enhanced capability of muscles to adapt to burning fat, a desirable trait for endurance athletes.

Performance Outcomes: Research Insights

Despite the biochemical benefits, improved performance metrics, such as speed and endurance, are not guaranteed by fasted training alone. 

Research shows that while fasted training enhances metabolic adaptations, it does not consistently translate into better performance during competitive events. 

For example, a controlled study involving two groups of athletes showed no significant differences in VO2 max improvements or time-trial performance between those who trained in a fasted state and those who did not.

Innovative Approaches to Fasted Training

Goar introduces a more extreme variant of fasted training that he has personally tested, involving a regimen of high-intensity training followed by a period of sleep fasting, termed “Sleep Low.” 

This method involves depleting glycogen stores with intense exercise, then fasting through the night and performing low-intensity training the following day. 

This approach has shown promising results in improving performance, as substantiated by several follow-up studies that confirm enhanced efficiency in carbohydrate utilization and performance outcomes.

Practical Application and Recommendations

For athletes and coaches looking to integrate fasted training into their routines, it’s advised to start gradually and monitor responses closely. 

Adjustments should be based on individual tolerance and training goals. 

Importantly, while fasted training can be a powerful tool for metabolic conditioning, it should be balanced with adequate nutrition strategies to avoid potential negative effects on recovery and overall health.

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Conclusion: A Balanced View on Fasted Training

In conclusion, fasted training offers notable benefits for metabolic adaptation but should not be overly relied upon for performance enhancement. Athletes should consider their personal health profiles, training needs, and the latest scientific research to optimize their training strategies. 

Engaging in experimental practices like the “Sleep Low” protocol may provide new insights and potential gains, tailored to the unique demands of their sports.

This overview of fasted training underscores the need for a balanced and informed approach to integrating fasting into athletic training, ensuring that it complements other elements of a comprehensive training regimen.


Julien Raby is the owner of BoxLife. He owns a bachelor in literature and a certificate in marketing from Concordia. He's Crossfit Level 1 certified and has been involved in Crossfit since 2010. In 2023 he finally made it to Crossfit Open Quarterfinals for the first time. LinkedIn Instagram Facebook

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