Fig.2.

10X healthspan/lifespan strategy #2. Minimize aging-related changes on a small timescale. Rather than waiting a lifespan to observe the effects of a putative aging-delaying/healthspan-increasing factor, one can measure an aging-relevant phenotype, ρ, on small time scale (e.g., hours) and identify changes that make the rate of change of the phenotype, i.e., derivative (Δρ/Δt), go from negative to 0. This requires highly quantitative, rigorous experimentation.