Comment by rsync | Hacker News Reader

Comment by rsync | Hacker News Reader

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"I'm personally very skeptical [as well]. I notice that almost nobody that recounts their fasting experience ever mentions sport."

Allow me to step right up.

First, as you might expect, aerobic and endurance exercise benefits greatly from being in a fasted (16-24 hr) state. You're light, quick and your body is devoting zero blood flow (and other resources) to digestion. I suspect you're not surprised by this.

Second, I do a 1.5 hour heavy leg workout which includes squats, deadlifts and other assorted "big" movements with weight that is significant, compared to my body weight. No issues at all. I wouldn't do this on a 24 hour fast, but it is my regular habit to do this workout while in a 16-18 hour fasted state and in general I have very slightly better results than if I had eaten recently. Again, the issue is the amount of blood flow (and other resources) your body is putting into digestion.

Finally, while it is easy and enjoyable to do my BJJ workouts in a fasted state, I cannot, then, do several rounds of sparring at the end without more recent calories. Or rather, I can but I after round one or two I am running out of gas.

YMMV. You should just try it. It costs nothing.

First, as you might expect, aerobic and endurance exercise benefits greatly from being in a fasted (16-24 hr) state

If that's true, why isn't it a universal practice in amateur and professional athletic competition?

(Or, for that matter, why isn't it banned?)

I can't speak to endurance (I got into IF after my endurance-athlete days) but I know that body weight-based athletes do this to perform better. My experience is specific to rock climbing.

When you are right at the edge of your abilities being just a couple pounds lighter can feel like a world of difference (people hone down their rack to precisely what they need for a route, nothing more), especially on sport and boulder problems. My anecdata points to it being great for the project/performative aspects of the sport but as a tool for consistent progression/improvement, I am less confident in stating anything.

> First, as you might expect, aerobic and endurance exercise benefits greatly from being in a fasted (16-24 hr) state. You're light, quick and your body is devoting zero blood flow (and other resources) to digestion.

I'd say it depends greatly on the effort and the individual. Long, slow distance for someone who is accustomed to training fasted? Fat stores will suffice as an energy source.

But add in some intensity and that's gonna be rough without much glycogen in the tank - which will be the case if you've been fasting for the past 16-24 hours.

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