5 day fast with Fitbit deep dive
112
2022-02-04に共有
For the $26 body composition scale and app I use: amzn.to/3oq5k1R
(those are affiliate links, meaning if you buy from there I get a few bucks and you pay the same price)
As a quick recap, for the last 5 years or so I've done an extended fast once per calendar year. I started out with just a 3.5 day fast, and have done just over a little over 5 days. The reasoning is that extended fasts not only activate genes that help with longevity, but there's something called autophagy that starts kicking in. That's essentially where your body starts eating itself for energy, but it does so by starting with misfolded proteins or poorly performing cells. This happens around the 3 day mark, as does new stem cell generation. And, there's more science coming out all the time about this, and as I get a better understanding of my body and what's going on, I can tweak things over time.
So, what does my Fitbit Sense say about this last fast?
If you've seen any of my other fasting videos, you may recall that I say that fasting really puts you in no worse a state than getting a bad night of sleep. Well, it turns out, that is because I'm literally getting a horrible night of sleep. Even when I gave myself a full 8 hours of sleep, my REM sleep and deep sleep were absolutely horrendous, and the time that my heart rate is under my resting heart rate (which is a good indicator of your body being able to recover) was horrible as well.
I had previously mentioned that I felt a little bit more restless and that I needed less sleep as well. Well, it turns out that I'm not really more restless, perhaps it just sticks out in my mind more for being more uncomfortable. My joints in particular were really uncomfortable and sore the first night for some reason, but my % of restlessness and movement was still low overall. And, I did feel like I could get up with less sleep than usual, but I was really just confounding different variables here. I could get up and thought the sleepy feeling was from fasting, but really it could've just been from getting such bad REM and deep sleep that getting up earlier really didn't impact it so much.
One thing that I didn't expect was for my resting heart rate to shoot through the roof. Resting heart rate is typically associated with your cardiovascular health, and I thought that wouldn't really change so much over just 5 days, but I was wrong. My resting heart rate is generally in the 52-56 bpm range, but for the first time ever I went above 60, getting up to 61 before I broke my fast. And, this wasn't just a one-off kind of thing, it was a clear trend of my resting heart rate raising 1-2bpm per day. My only guess as to what is going on here is that my body is attempting to pump the heart more in an effort to get more oxygen and other things to my body.
Also, on the topic of the heart, my heart rate variability became pretty horrible as well. Heart rate variability is a measure of whether your nervous system is in sympathetic or parasympathetic mode and to what degree. This is essentially whether your body is ready for a fight or flight response, or is more relaxed. If you think of hospital scenes on TV where there's the EKG showing the heart beating and there are multiple highs and lows, the heart rate variability is essentially measuring the time between the various points and seeing if there is variability. The less variability, the more stressed your nervous system is and your body has essentially put you in fight or flight mode. My heart rate variability dropped tremendously. I've only ever seen it get so low either when I was sick or right after my 2nd covid vaccine where I know my body's immune system is in overdrive trying to "fight" the vaccine.
The HRV isn't as super surprising because the longevity studies I've read about tie the gene activation of fasting to essentially being a stressor, but I am surprised that it went so low.
Now, it's 6 days later, and I've increased my weight by 10lbs, my resting heart rate is back to 53, my HRV has increased back to its usual range, and after my 2nd night of sleep post-fast my REM and deep sleep started shooting through the roof.
So, let me know if you have any questions. Again, I recommend trying to fast if you're in it for longevity purposes and not for weight loss purposes, and because I do believe it gives you a different level of mental resiliency and a type of antifragile mindset when you expose yourself to tough times and come through and surprise yourself. And, really, fasting isn't nearly as difficult as you might think. There's a mild, persistent hunger, but it doesn't keep you from your mental and physical tasks.