YES!

I just spent a bit over an hour on the treadmill, almost non-stop (one water break). I got in a bit over 2 and a half miles, which means that my total for today is over the 5 miles I needed.

I just looked at the sample training schedule on the 3-Day website, and I need two five mile walks this weekend to start catching up. If today is any indication, as long as the treadmill is working, I can do it.