Megan, what is a windshield wiper? You are going to LOVE running HIIT, it is totally the greatest workout ever. Not only do you burn about a million calories, and get the afterburn effect, but you actually improve your running speed while you're at it.
Personally I am a relatively slow runner in general, so my HIIT run speeds are lower too. I couldn't really say what speed I'm going when I run outside, but last time I did it on the treadmill this is what I did:
Minutes 1-5: warmup walk at 3.5-4.2mph
Minutes 5-8: 5.3mph warmup
Minutes 8-20: 1 minute at 6.3mph alternating with 2 minutes at 5.3mph (total of 4 fast intervals)
Minutes 20-25: cooldown at 4.5-2.5mph gradually decreasing
The speed to choose really depends how fast you usually run steady-state. If you can run for about 25 minutes at 6mph steady, I would try doing fast intervals at 7mph and recovery at 6mph or maybe 5.8 or so if it's too tiring.
My Monday workout:
Running OUTSIDE!!!! With the dog!!!! In short sleeves!!!!
5 minute warmup walk
2 mile HIIT run -- steady run for the first 1/2 mile, then 1 min sprint alternating with 2 min recovery. Total time for the 2 miles 21:49, a new
PR!
5 minute cooldown walk
5 minutes stretching