Fartleks Getting Faster (Fart-ier?)

I hit the indoor track at the YWCA of Minneapolis again on Friday for some Fartleks:

The 6-laps-to-a-mile track at the Midtown YWCA.

I did the same workout that I did exactly 4 weeks before, and here's what I said about it back then (as noted in this post):

I did hard efforts of 2, 4, 6, 4, 2 laps, with 1 easy lap of running between the efforts. So that was a total of 3 miles of hard running, with the longest effort being 1 mile (6 laps).

I ended up running all of the hard efforts right at (or JUST over) 6:00/mile pace. Here are my 2 lap splits (1/3 mile) and totals for each fartlek:

2:00
1:19 jogging
2:02, 1:58 = 4:00
1:19 jogging
2:03, 2:02, 1:59 = 6:04
1:27 jogging
2:00, 2:01 = 4:01
1:24 jogging
2:00

Well, I did the exact same workout, but only this time I had the knowledge that last time I did it right at (or just over) 1:00/lap, so I knew that I'd want to try to better that a little. If I could. I ended up running this:

1:55
1:12 jogging
1:57, 1:56 = 3:53
1:12 jogging
1:59, 1:57, 1:57 = 5:53
1:18 jogging
1:57, 1:55 = 3:52
1:17 jogging
1:54

That was SUBSTANTIALLY faster than 4 weeks ago! Not a SINGLE split slower than 6:00/mile pace! My fast running 4 weeks ago was 18:05 for the 3 fast miles, and this time it was 17:27 for those 3 miles! But surprisingly, even my REST times were faster: 5:29 total for 4 easy laps last time, and 4:59 for the same 4 easy laps this time!

Now I don't think I "gained" that much fitness in 4 weeks. Last time, it was my first workout like this in a long time. So this time, I knew what it felt like last time, and I could "up the ante" a bit more. (It was like when I ran my first 1 mile race in Dec of 2008 - I finished in 5:00.7. Just 2 weeks later, I ran the same meet again, and took 6 seconds off my time running 4:54.6. I didn't get that much better; I just knew how it felt and what to do.)

Regardless, it looks good on paper! :)