I'm not talking about the what someone's longest run of the week is (that could be 8 miles for some people), but a long run as a workout. My friend (via his coach) insists that a long run needs to be at least 90 minutes to get the benefits that a long run is suppose to accomplish. Previously I was told that a long run just needed to be 60 minutes.
I did try to google this - but does someone here know if something does happen after 90 minutes that doesn't happen after 60 minutes? Increased mitochondria, capillirization, increased efficiency, some kind of increased ability to utilise fats... whatever.
Oh, to be clear, this is not marathon training, just for running cross country, so not worried about hitting the wall or whatever marathon runners worry about with their long runs.