I’ve had two going from '77 or so to present. Admittedly not hunting as much from Utah, but when I hunted a minimum of two days a week particularly whipping in, well, you just need two, it’s too much for one.
They were out in large pastures, group settings, at least half the day (or night, depending on season). So, once fit, they pretty much kept themselves fit, I might hack them lightly once or twice between their hunting days. More often, they would just get ridden on hunting days. Once fit, a horse will hold its fitness for a good month to 6 weeks, if they have that minimum 12 hours of turnout. 24/7 with shelter access is best.
Getting them fit, getting towards start of cubhunting, of course roading hounds was part of the program, but I’d ride each one 2-3 times a week, an hour or two of mostly trot sets. Ponying is also a good option.
When I wanted to get them more ‘racing fit’ for pair races in the spring, I’d schlepp to barn on cold winter nights, and gallop them around the perimeter of the pasture, close enough to fence to more or less use that as reference. Obviously the moon is your friend there, but even when pretty dark, horse can see fine, and of course knowing there are no holes in the familiar pasture is a good thing.
And excepting one that was killed by lightning at 14, they all hunted hard to ages 20, 23, 26 and 28.
And yes, I have two going still even though not hunting regularly. I’d quite sensibly gotten myself down to just one (plus a retiree, at the time). And then made a splurge buy. Because, well, a second horse for packing or the occasional guest is just a nice thing to have. And ironically I was poised to sell one last summer and be sensible- but my non-horsey hubby used the mare to practice for our riding safari last fall, and after she cheerfully packed him around to practice, well, apparently, no, we cannot sell her, he might want to ride her again in 5 years or so, maybe!
And I do work full time (that’s what vacation days are for, is hunting). During cubhunting way back, when the meets were at 6:30 I was in the office by mid-morning.