Something isn’t adding up here.
Is he supposedly walking 15 miles one way or round trip.
It takes about 2 hours to RUN a half marathon (13 miles)
I am not a runner but running a half marathon 5 days in a row every week, for months on end, seems like it would be nearly impossible?
My personal best, at age 39, 1:20:02. Nowhere near world class:
The official IAAF world record for men is 58:23, set by Zersenay Tadese of Eritrea on March 21, 2010 at the Lisbon half marathon in Portugal,[4] and for women is 1:05:06, set by Peres Jepchirchir of Kenya on February 10, 2017, in Ras Al-Khaimah, United Arab Emirates. (Wiki)
There are people out there who run much more than this. A few years ago a dude I’m familiar with ran 50 miles every day for 50 Consecutive days. Endurance is much like dedication, it’s a matter of what someone is prepared to get completed.