I live on the west-facing slope of a hill called Palatine Hill, on the west side of the neighborhood of Fremont (it's more commonly referred to as Phinney Ridge).
Back when I worked for zulily, I came up with a very high-impact workout that also took up very little time (my goal was "under a half-hour"). The first part was working out on a heavy-bag for about 10-12 minutes (about 3 songs), and the second part was this run, which takes approximately 16 minutes (about 4 songs).
It's essentially a run to the bottom of Palatine Hill and then a run straight back up. The elevation gain isn't huge (it's about 265 feet), but what's convenient is that it occurs in blocks, so I can generally sprint up a block and then take a quick rest (usually about 30 seconds) before proceeding up the next block.
The run looks like this:
I have captured a handful of Garmin stats for this one (shown is the time to run each). My best time is an average 10:01 min/mile.
* Note that this run always begins and ends at the same position, so when the map shows differently, that's a problem with the Garmin GPS (it also messes up the distance in these cases .. the time is the only thing that's correct)
You can see that the 1st part of the run is down the hill. The most difficult part is just before the 1st break (where my pace goes to zero). This is up a 2-block section of incredibly steep street that invariably leaves me gasping for breath. The other breaks are after the remaining 1-block sections.
I've been recovering from a couple of injuries, and so my trail runs have become much shorter lately, and I've also cut way down on the frequency of this training loop, but I hope to return to running this regularly, and to work my way up to running it 4x, for a total elevation gain of 1,060'.