Today’s episode features Greg Potter.  Greg is a former sprint coach (he has written some fantastic Q and A pieces for Just Fly Sports in the past regarding all things sprint training) who is now a Ph.D and expert on Circadian Rhythms and their impact on our health and well-being.

Greg is the former content director at HumanOS.me and now works as the chief scientific officer of a health-tech startup.  Greg’s work at the University of Leeds on sleep, diet, and metabolic health was featured by the likes of the BBC World Service, the Washington Post, and Reuters. As a sprint coach, Greg coached a sprinter to four gold medals at the European Championships. Greg has also worked with groups such as The United States Naval Special Warfare Command on health and performance optimization.

Today’s show is all about our body’s “clocks” (Circadian Rhythms) impact our health, metabolism, ability to train, and our ability to recover via sleep.  It’s important to know how to train, but it’s also critical, especially in our modern digital age, to understand how to better recover and live based off of our innate wirings.

Topics addressed on today’s show include the basics of circadian rhythms and impact on nutrition, sleep, training, and metabolism (fat loss).  Greg also gives plenty of tips and ideas on how to optimize our lives based off our own circadian rhythms.  The back half of the show in particular has a lot of great concepts on training optimization based on time of day.

Today’s episode is brought to you by SimpliFaster, supplier of high-end athletic development tools, such as the Freelap timing system, kBox, Sprint 1080, and more.







Key Points

What circadian rhythms are and what they mean to us
What the modern lifestyle (in terms of artificial light cycles and ever-abundant foot availability) means for our health and function
The metabolic advantages of early day, time restricted eating
Nutritional concepts in a non-training day for a speed-power athlete who wants to stay lean
Greg’s take on the ketogenic diet
Ideas on timing multiple workouts in a day with various emphasis
Variation in VO2 max based on time of day
The importance of naps for strength and power performance
The importance of body temperature in speed and power performance
Artificial light and its impact on our daily rhythms and clocks
How to use light-based products and apps to help synchronize the body clock





“The most important time cue in resetting our biological rhythms with the 24 hour day is the light/dark cycle and the problem of course is that now we live these 24/7 life cycles where we have artificial light cycles at night, we spend too much time indoors during the day time, we have round-the-clock food access, and because of all these different factors we behave in a way that is discordant with our biological rhythms”

“Our bodies are best set to digest food in the daytime”

“Insulin sensitivity is higher in the daytime than the nighttime, our bodies are primed for eating during the daytime”

“Skipping breakfast is associated with negative health outcomes and eating at nighttime is associated with negative health outcomes”

“(For time restricted eating) I would stick to a 6-12 hour caloric period that finishes at least 2 hours before you plan to go to bed, but earlier than that is probably better.”

“What we want is a nice high-amplitude rhythm in core body temperature… it’s generally highest in the late afternoon, which is the best time for strength and power exercise for that reason”

“I think it’s smart to give our digestive tracts a break each 24 hours”

“(Peripheral clocks) seem to be primarily set by our food intakes each day”

“I would recommend that your final meal of the day is relatively small compared to others”

“When people consume regular meals at scheduled times, they tend to burn more calories after consuming those meals”