It's interesting how the numbers look when your body is adapted to a high-fat ketogenic diet. I'm talking about blood glucose and blood ketones.
So, I've been tracking my numbers (ketones and BG) at least twice daily since last December. If I weren't I'd probably not be in ketosis. Long story short, it took a lot of tweak, drastic carbohydrate reduction and daily measuring to get the ketones elevated.
When the metabolism changes so much, energy substrate dynamics also change near exercise. While I did not experience any downsides when it comes to my lifting performance, yesterday I had a high intensity competitive swimming race. In the first lap, it was all out effort and it kindof hit me hard. But then, after 1-2 minute break I found a relatively high intensity pace that I could keep up to. And I maintained that high pace for the 40 minutes of the competition. Heck I think I would've been able to keep on for another half an hour (at least).
Before race ketones were pretty high - 3.7mmol/L in the fasted state. Yesterday I had 2 meals, both after the race (at 4 hours and at 10 hours). Ketones were even higher last night after meal, while blood glucose was relatively low.
There's nothing to prove with this, just a simple experiment of the dynamics of energy metabolism in high intensity exercise with keto-adaptation. Looking forward for more experiments.
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Cristi Vlad Self-Experimenter and Author