Supplementing nitrate - didn't work for me. Seems to work for beginners but not for people with a higher VO2max. I had no noticable effect with it. See https://pmc.ncbi.nlm.nih.gov/articles/PMC4425174/ and my review of nitrates+ here https://newzapiens.com/brands/4endurance?rid=9fa184f7-06cc-4b0d-91ce-26a482b6317c

No answer yet. The question is always when exactly should I feel a difference, e.g. with taking collagen or NMN? NMN I stopped because I learned not enough science evidence of effect, collagen I don't see or feel any difference yet after taking it for 6 months now. Even if I'll do a dexa scan now and another in one year and let's say bone density got better even if I got one year older, could that be a result of collagen or just because I did better strength training or because of a hormone therapy? And could a longevity doctor help me with finding the answer? @Dr. Thomas Voit? @Titus Maniera?

I've seen countless wellness trends come and go, and your point about the gap between solid science and personal experience truly resonates. For me, that has been certain forms of high-intensity interval training (HIIT); while the studies are excellent for cardiovascular health and efficiency, my body simply feels better with lower-impact movement now. I’ve learned to trust my body's signals over the latest "must-do" regimen, prioritizing consistency and joy in movement over perfect adherence to a protocol. It’s a great reminder that the best plan is always the one that genuinely works for the individual.