A couple of days ago I got the crazy idea of going running at 4am so as to make better use of the first hour of my Polyphasic day (currently I spend that hour sitting at my computer feeling tired and looking at Digg). So I gave it a go and discovered that going running at 4am is less like going for a run in the morning and more like going for a run in the middle of the night. I.e. a bit weird. So I went back inside and sat at my computer.
But the idea wasn't entirely dead. First I established that I didn't actually need to go for a run at the same time as Tina (who most certainly didn't want to go running in the dark). Then I spent a few days doing a couple of industrious things:
Firstly, I made a fully-fledged workout program, including plans for runs each weekday.
Secondly, I made some experimental "HIIT" (High Intensity Interval Training) mp3's. When you're running outside, you have no real way of timing when to start and stop your intervals (unless you want to look at your watch all the time). The idea behind the mp3's is to let you know when to start sprinting and when to jog (e.g. 30 second low intensity, 15 second sprint, repeat).
So, for example, my current set of tracks are all 45 seconds long, and each has a small "Beep" 30 seconds in to let me know it's time to sprint, and then a second, lower "beep" to tell me to jog again. My epiphany was to overlay the beeps onto sections of songs that already have high and low intensity parts. Think of how many songs incorporate a quite, calm build-up to a sudden explosion of more intense music. All I did was time it so the sprints start right on the point where the music gets intense. Aside from letting you know when a sprint is coming up, it's a great motivator to really give it your all.
To make a complete HIIT session, you combine the different tracks however you like to a total time approximating how long you want to work out for. Just make sure you don't have it on loop or you won't know when to stop... and if you are doing HIIT properly you will be very keen to stop.
So today, at 4:30am (I woke up a little late) I went running in the middle of the night, and it was great. I much prefer running outside to the treadmill as you actually experience how quickly you're moving, and you can push yourself as hard as you like rather than being limited by a treadmill which takes 15 seconds to get up to maximum speed each time.
As for how I fared on the actual HIIT; I found it substantially more challenging than our treadmill approximation of HIIT, because when you're actually running a sprint really is a sprint. To use Geoff's word, I got dominated. But I still felt great for having done it, and look forward to my jog tomorrow morning.
P.S. If anyone is interested in my schedule or the HIIT tracks, let me know in a comment or email and I'll make them available here on the blog. I just need to sort out a decent file-hosting service.