I was scared of this workout, with good reason. It's probably the hardest workout I've ever done. The intensity is not maximal, but it's a good solid moderately hard-hard effort for an hour and 30 minutes. Yep. That's a long time to be working so hard. It was almost like doing a race; a bit easier of course, but still very, very tiring.
The weather didn't particularly help. It was 70F (21C) when I started and 74F when I finished, with 52% humidity. Definitely on the warm side, at least for me (and for Salt Lake). I had to stop to drink at 6K, 10K, and just shy of 13K (when I messed up my watch...pressed stop and then didn't press start again for too long - oops).
Jim said to start off conservatively. I did, doing 5:50 for the first km. The first 5K felt conservative, and I got there in 29:41. The second 5K felt moderately hard; my legs started to tire around 8K, but not too much yet. I got to 10K in exactly 60:00 (30:19 for the second 5K). Finally, the last 5K felt hard, of course. My legs were quite tired by 12K or so, and I really wished I could stop, but I only had 3 more to do. I managed to do the last ones fairly fast, considering how I felt. Like I said earlier, I messed up my watch on one of the medium 500s, and so the time is off by about 1:00-1:05. So I got to 15K in about 1:30:21-1:30:26 or so, for 30:21-30:26 for the last 5K. That's good considering how I felt! I managed to keep it almost as fast as the 2nd 5K.
My fast segments were very consistent, ranging from 2:53-2:56, with the last four at 2:53 (I worked those hard!). My medium segments were more varied, starting at 3:01, 3:01, 3:04 with the rest ranging from 3:06-3:10, with one 3:12 (and one unknown due to watch error, probably about 3:12?).
Total time for 15K = 1:30:25 (more or less), ave HR 155, ave pace 6:02/km.
I've been pretty tired all day. This was a hard one, for sure.
Garmin connect data here.