I used to be on a 4 day cycle, but I wanted to get more in the flow with everyone else, so I'm weekly now. If I could have gotten in months of Base I would have, but I had to ramp up quickly. So I started doing just a few measured routes everyday to build up, which took 6 weeks. Now I'm getting back to normal with this program:
Monday - One hour trot to the start of a 500 yard long section of trail leading to the summit of Green Mountain. There's a little acceleration at bottom then serious steps up to the top. Catch a few breaths at the top and jog down. 2:40 each, 7 repeats. Jog back down to car.
Tuesday - Long and hilly, 2.5 - 3 hrs. Not a hard effort, but still getting in a few thousand feet.
Wednesday - Morning instead of evening, otherwise same as day before. May pick up the pace on some climbs, fartlek style.
Thursday - Hill intervals again, this time on pavement. A :35 warmup, then 5 X 3:50 intervals, so the total time is the same as Monday. We jog down after each one, barely recovering in between. The goal is to go really hard while still maintaining consistency on each repeat. :30 cooldown after.
Friday - A morning run so I'm recovered for the important Saturday run. Same as Tue and Wed. Easily doing 3,500' on these days.
Saturday - Third of the three hard days. More than tempo, but a notch below race pace: you got one gear left, but you don't use it. We drive down to Pikes Peak, and run :45 on rolling terrain to Barr Camp, a quick break and drink, then push it hard to Timberline, take a hydration break, then a fairly hard effort to the summit. Then hitchhike down the auto road back to the car, which is surprisingly easy - people take pity on skinny half-dressed runners standing around at 14,110'. About 2 hrs total.
Sunday - Longest run, approaching 4 hours. Easiest effort - get out there and enjoy it, burn off whatever fat I have left. Thousands of vertical - all hills.
Misc - I also like to squeeze some striders a few days a week.