I disagree, running and walking are not really substitutes from a health standpoint. Walking has a lot of health benefits but they're largely orthogonal to trad

I disagree, running and walking are not really substitutes from a health standpoint. Walking has a lot of health benefits but they're largely orthogonal to traditional vigorous exercise. Modern research has identified that the major mediator of exercise's physiological benefits is the down-regulation of the adrenal axis.[1] In other words, activating the fight-or-flight sensation is a key component of an exercise program. It's also why very high-intensity exercise seems to produce the most rapid improvement in key biomarkers.[2] Many people don't like vigorous exercise because they feel like they're dying from the strain. However that painful stressful feeling is largely essential to the process. [1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3010733/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3010733/ [2] https://www.sciencealert.com/just-12-minutes-of-intense-exercise-is-enough-to-change-biomarkers-in-your-blood https://www.sciencealert.com/just-12-minutes-of-intense-exer...