Here's one study amongst many: https://www.frontiersin.org/articles/10.3389/fpsyg.2018.02612/full https://www.frontiersin.org/articles/10.3389/fpsyg.2018.0261..

Here's one study amongst many: https://www.frontiersin.org/articles/10.3389/fpsyg.2018.02612/full https://www.frontiersin.org/articles/10.3389/fpsyg.2018.0261... "Results: ...Groups of moderate (≈40) and high (≈49) fitness outperformed the group of low (≈31) fitness for inhibition and episodic recognition, whereas no significant differences between moderate and high fitness were observed (ANCOVAs). Breakpoints between benefits from VO2max for inhibition and recognition were estimated to ≈44/43 mL·kg−1·min−1 (multivariate broken line regressions)." Be a moderately fit, at the very least. Resistance training will reduce side effects of endurance training (muscle loss and hormone profile) and also would help reduce all cause mortality: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2453303/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2453303/ If you would like to live long and be smart, walk (jog, run) and hit the gym. ;) Actually, I found that searching for the balance is a congitive test in itself. It can be said that the way you solve it describes and defines you.