My last backpacking trip was over a year ago, but I've got my next one coming up in a week. Life has been hectic and unorganized. I've known for a long time I had a lot of prep work to do: making/tweaking gear, preping food, packing, and physical training. I've been planning it for a long time, but always seem to make glacial progress on all of this due to other commitments and, frankly, just being exhausted mentally or physically. I'm having to make compromises on gear (again), and I'm okay with that if it gets me out there, but it's just hit me how little time I have to make sure my legs and back are up to it.

I walk almost every day, but it's short distances carrying little weight. My plan is to put in 7-10 miles daily for three days with a total elevation gain of 5689 ft and total elevation loss of 5687 ft. This is all at low elevations, about 1800 ft sea level max. At this point, I'm wondering if it's safe to train to that point in such a short amount of time. I can change my plan if I need to, but if there's a way to get "up to speed", that would be better, even if it means losing some sleep to make time for it.

I know when runners are trying to train for a race in a very short amount of time, they do fartleks (aka "speed work" or "speed play") and then taper the amount of training down to next to nothing the last couple of days, maybe even leave a day of rest between the last workout and the race. So, I'm wondering, what's the backpacking equivelent of a fartlek? I need to come up with a training plan. Luckily, there's a nice urban trail where I live that I can train on. Depending on my exact route (use a loop at the end or backtrack the whole way), it's about 6.6 to 7.5 miles from my house to the end of the trail and back. Here's my tentative idea:

Thu 4/6 - 6.5+ miles with empty pack
Fri 4/7 - rest day
Sat 4/8 - 6.5+ miles with loaded pack
Sun 4/9 - rest day
Mon 4/10 - 7.5+ miles with loaded pack
Tue 4/11 - rest day
Wed 4/12 - 6.5+ miles with loaded pack
Thu 4/13 - travel day/no walking
Fri 4/14 - first day of backpacking

Those of you with more experience doing focused physical training, does this seem doable, and will it put me where I need to be safely? Do I need to adjust distances, say maybe a lower mileage on the 12th or more miles on the 10th? Should I do fewer rest days, 2 or 3 walking days in a row?

By the way, I'm 5'7", 133lbs and not in horrible shape, but not really in good shape either (desk job, limited recreation time, and admittedly a diet that could be better).