Thank you guys for the feedback. I was mostly thinking for the mental callousing aspect too I guess. In terms of weekly training for something like PJ Indoc I had in mind something like this
Mon: AM Gym (full body) PM Track intervals
Tue: AM Swim. PM Easy 6-8 mile run
Wed: AM Gym (full body) PM Ruck (Uphill intervals w/water jugs)
Thu: AM Swim
Fri: 3-4 hrs Long Run
Sat: 2-3 hrs Swim + Cals + Heavy Ruck (on flat to rolling roads)
This would just be a type of "endurance base phase" leading up to something more swim/strength/ruck intensive 2 months prior the shipping.
Just my personal opinion:
- if you have the endurance to go for an hour, I think it would benefit you to work on speed in the 3-5 mile range rather than running for four straight hours at a sluggish pace.
- running slow for half a day will make you great at running slow for half a day, but it will lead to injury if you don't factor in time for mobility/recovery.
- it's just boring. The line of thinking goes: if I can run 12 miles, the 3 mile test will be so easy! But that doesn't really translate when you are used to 9-10 minute mile paces and everyone else is literally sprinting their 3 mile test but can also lift way more weight than you because they had the time leftover to lift weights AND do cals AND do some mobility/recovery work. When it comes time to pick up awkward, heavy things and walk for long distances with them, nobody will care what your marathon time is. It's easy to say you won't neglect PT or cals or lifting while training for ultramarathons, but after a 4 hour run the last thing you are going to do is an hour of calisthenics. Biologically, your body can not run 70-80 miles per week AND maintain muscle mass. I'm sure there are exceptions; but I'm also relatively sure they are few and far between.
All of this to say: will running a marathon help you mentally? Of course. It will make you really good at being tired and bored with a huge amount of mileage ahead of you. But I don't think the juice is worth the squeeze as far as time management goes.
If anything, maybe do it once every few months just to get outside of your comfort zone.
Disclaimer: I have never, am not currently, and will never run an ultramarathon, based purely on the principle of running being an activity created and encouraged by Satan himself.