As previously announced, plans are to run an ultramarathon this spring. In particular, the Tinajas 100k in Colorado Bend State Park.
I haven't taken running seriously since I lived in California, four years ago. I'm still in shape generally speaking, but nowhere near the runner I used to be. It'll be a while before I can expect to hold a 4:00/km pace for any significant distance.
Since 100 km is farther than I've ever run before, it'll take some time to build to that from a starting point of "I can still run OK, kinda, but not too far or fast." Training began the day after I arrived in Plano from the Western States bike tour. The first week, I ran three days, and biked the rest. The second week, four, until I was running six days a week and biking on the day off.
Of course, I picked the hottest time of year to start training. At sunrise, the temperature is already 25 C (~80 F), and climbing. And when you're not in your best shape, Texas summers are devastatingly hot. On most training runs, it hasn't been a matter of lacking leg strength of being unable to catch my breath. It's simply a matter of overheating.
Worse, school is about to start. The only way I could continue running in the morning is by waking up at 4:30, warming up, stretching, running, cooling down, stretching, showering, eating breakfast, riding to school, and changing clothes, all before tutorials start at 7:40 AM. And that's with no hiccups. And I'd have to run in the dark, which I prefer to avoid.
Instead, I'll be running just before sunset, when it's still about 30 C (~88 F) outside. Wonderful.
While I haven't gotten faster, running each day has gotten a little easier. From running only three times a week for a total of 27 km, I'm up to six runs a week for a total of 78.3 km. And somehow, it seems more effortless than it did less than a month ago. I've also lost 2 kg (~4.4 pounds) already, with another 3 kg to go if I want to get down to a competitive race weight.
About a month from now, temperatures will start cooling off, and only then will I be likely to get significantly faster. But for now, it's good enough to start building a base.