We know that fasting can turn on good genes and turn off bad genes, like those linked to liver, breast, lung, colon and brain cancer. So I wondered whether fasting could have the same effect on genes that promote athletic performance. The answer I got was yes, fasting can improve athletic performance!

A study on Russian elite endurance athletes found the group of athletes had an increased frequency of the UCP3 (mitochondrial uncoupling protein 3) gene compared to a control group. Simply put, more UCP3 equated to better athletic performance.

They found that two types of fasting could activate the gene expression of UCP3 independent of genes necessary for lipid transport and oxidation in skeletal muscle. Specifically, it found that a 15-hour fast (aka intermittent fasting) increased the UCP3 gene expression 5x in the skeletal muscle. And a 40 hour fast increased the gene expression 10x!

Could fasting be an untapped secret to better athletic performance?

Here’s what else happens at 40 hours of fasting, dopamine receptor sites get rebooted, aka “the happy hormone” and 40 different metabolites kick in that slow down the aging process.

So, here is what I would recommend for my endurance athletes, marathon runners, spartan racers, cyclists, etc: once a month, try doing a 40-hour fast. This can look like eating dinner on Sunday, then breaking your fast on Tuesday afternoon.

Now, if you’re looking to build muscle with fasting, make sure to watch my 3 key strategies to building muscle, where I talk about protein cycling to hit a sweet spot of performance optimization. I have an infographic in my instagram feed on how to protein cycle and fast for athletic performance.

And if you’re new to fasting, start with my Beginner’s Guide to Fasting, and make sure to join our free Resetter Collaborative on Facebook, where I lead you through fasting together one week every month and we practice these fasting principles.