For the last few weeks one undercurrent of performance movement, intermittent fasting has been fascinating to me. Many competitive athletes who follow LeanGains, Warrior Diet, Eat Stop Eat – advocated significant improvement in focus, muscular performance and stamina, although not endurance. Most intermittent fasting regimes discourage doing endurance training during fasting hours.
I’m sure all results are very personal and mine is far from a scientific analysis and certainly not an expert one, here are a couple of my insights:
1) You get hungry when you are used to eating. Martin Berkhan calls it hormonal entrainment patterns, which basically means that getting hungry is sometimes a matter of habit. In my case, I was never hungry in the 16-hour daily fasting regime of LeanGains. Today I tested a 24-hour (Warrior Fasting) protocol and I got hungry at around 23 hours. So Martin may be right about the 20-24 hour window being our first real hunger signal. Some say Paleo followers get hungry less often than grain eaters so I’m sure there are other factors like that too.
2) I have not noticed any impact on strength or stamina training routines as long as strength training was performed on a fasted and not fed state. I did find that endurance (long distance running, rowing, swimming) gets better in a fed state but is sluggish in a fasted state. Metcon results for me were mixed. Some days were very focused on fasted state and others weren’t and I probably do not have enough data to find any correlation.
3) Mental training is much more focused. Maybe the old yogis were right about their fasting protocols. I find that meditation and warrior yoga as prescribed by SealFit is much easier in a fasted state than it is in a fed state. (To be clear, SealFit does not prescribe any fasting protocols).
As the months progress I hope to report more of my personal experience to validate if there is or is not any performance to be gained for me from intermittent fasting beyond the 2-3 hours of freed up usual breakfast and lunch time.
I will know for sure after the 5 long Spartan races coming up in the next few months.
