Good luck with the training! I'm also doing my first 50 in May to celebrate my 60th birthday. More than 17K feet of elevation gain. https://www.maxi-race.net/en/races/maxi-race/ I have 30+ years of marathon and long-distance tri experience, but my longest running race has been 50K and that was 30 years ago. I'm planning to build my weekly mileage from 30 to 50 miles by April. I'm hoping for a finish time around 18 hours, walking every ascent. I ran on parts of the course several years ago so I know what to expect.

I'm focusing more on staying healthy as I increase the run mileage than I am on the long weekend runs, which may end up being a mistake. All my runs are on trails or grass. I did a 30-mile hilly (for Ohio) trail run last month and plan to do a 40 to 50 mile training run in mid April. I have always focused on my finish times and AG placings, but my sole goal in this one will be to finish.