I think people are right about "noticing" things, I'm not sure what people are trying to notice without lab work and testing like pre/post BP and HRV and other factors. Also it may only be a significant impact over the long run. Like, if senescent cells are something that builds up over time then killing what few there are in one's 40's may stave off a buildup for a decade.
I'm one of those who questions "noticing" things, and I'm not sure what to notice by trying various experiments combining fasting with D+Q. I did these self-experiments last year (D+Q+ PF), and what did I expect to feel? I don't know. But I had blood tests taken before and after, and the numbers didn't change from healthy baseline.
Regarding (unreliable) subjective experiences, however, I now notice both higher energy levels and lower energy levels.
For higher energy, I mean once my body gets revved up and into action, I have so much energy it's ... sick. Like, I feel as if my body can go on and on into increasingly extreme physical exertion. I like it. My increased stamina is remarkable, I'm even called "Energizer Bunny" by colleagues, and feel as if I have to work sometimes to contain high energy. I wish I could bottle up that extra energy, and hold it in reserve for when I need it.
For lower energy, I notice that once my body calms down and I sleep, or I have extended rest days from my vigorous profession, I feel like I could just hibernate the winter away. I'd be happy for months just being asleep. Put me to sleep, I'd sleep the months away in happy self-renewal.
Once I'm up, I'm way up. Once I'm down, leave me alone, world, I'm happy in recovery. I can't think of a way to measure these two energy states, though, without expensive brain imaging. Maybe treadmill testing lol.... And I'm not sure these effects are even real.
Prolonged fasting alone, with rest, is claimed to send the body into deeper regenerative cycles; breaking these prolonged fasts is then claimed rebuild parts of the body that were damaged, and then providing the body with more energy. That's the claim, anyway.
I'm giving credit to the fasting, though, and my 10% daily CR practice because (for me) I think the D+Q was useless in "clearing senescent cells." I'm not sold on these items clearing zombie cells in already healthy human bodies.
This writing has nothing to do with fisetin, however; but I also noticed nothing from high doses of fisetin combined with prolonged fasts (5-10/d).