[pvarangot]

When I was reading more about this most of the anti-aging benefits of fasting where explained by your body going into autophagy. I don't think just depleting your glycogen has the same effect and I didn't find any other reliable way of going into autophagy that didn't involve not eating for 36 hours.

Also a 90 minute run can have other side effects on people that just don't have the body for it. Even being fit and in my mid 20s and running with proper gear and on dirt and sometimes with a coach I developed plantar fasciitis in my 30s, I can do 10/15 minute runs and can hike and sky but I wouldn't risk a 90 minute run.