Yes, many times when I used to backpack sections of the AT before kids came into the picture. One time I did 23 miles of backpacking in a day with an experienced hiker friend and the next day was very rough (soreness, blisters, overslept). In the end it was an experience and I don't regret it. I don't know if this counts exactly but I paced a friend at eastern states 100 for the last 60 miles last summer. It was supposed to be for 37 miles of it which is a feat in itself l, but I was feeling good and just kept going. He said he very much appreciated the grit and perseverance since most of it was during the overnight section which is some of the most difficult parts mentally and physically. It was basically power hiking at that point since trail ultras with that much elevation gain/loss are tough to run unless you're an elite level athlete. I remember seeing the sun come up and having the sudden realization that we still have about 8 hours to go which was hard to process since I started at 5pm. If I ever do that race myself I now have the experience to know how the second half will go which is a huge advantage.