First, congrats on your self discipline.
Second: About running just one mile in a single day: Does have any physical benefit? (Yes, I know you run more than one mile on many days.) It would take more time to change in to/out of your clothes and shoes than run a mile. Plus it only burns 100 cals. Can you imagine someone writing here that they only swim 9 mins per day... Or bike 9 mins per day?
Yes. It does have physical benefit.
Here’s a study called “Minimum amount of physical activity for reduced mortality and extended life expectancy: a prospective cohort study” https://pubmed.ncbi.nlm.nih.gov/21846575/
From the abstract: “Compared with individuals in the inactive group, those in the low-volume activity group, who exercised for an average of 92 min per week (95% CI 71-112) or 15 min a day (SD 1·8), had a 14% reduced risk of all-cause mortality (0·86, 0·81-0·91), and had a 3 year longer life expectancy.”
Of course 1 mile a day is less than 15 minutes for most people, but that 92 min per week is just 13 minutes 9 seconds per day. I’m guessing with the long runs he’s over this when measured weekly.
There are other corroborating studies too.
Here’s from “Association between Bout Duration of Physical Activity and Health: Systematic Review” (https://pmc.ncbi.nlm.nih.gov/articles/PMC6527142/)
“Additional evidence was identified from cross-sectional and prospective studies to support that bouts of physical activity <10 minutes in duration are associated with a variety of health outcomes…The current evidence, from cross-sectional and prospective cohort studies, supports that physical activity of any bout duration is associated with improved health outcomes, which includes all-cause mortality.”
> Does have any physical benefit?
Compared to what? Sitting on the couch, snacking on chips? Of course.
Compared to letting your body fully rest during that day (perhaps in between longer runs).