I have short legs. So I start jogging when I hit about 4.5 miles per hour. However, that's on the treadmill. When I pace myself outside, I usually run at a 10 minute mile...but I walk at a 12 minute mile.
The other day my hubby (who has recently been exercising) went for a walk and I accompanied him. I wanted more of a calorie burn, so I jogged very slowly...but it was still a jog. We were probably at about 4 miles per hour.
I consider it jogging or running as long as both feet are off the ground at any one brief period of time, no matter what the speed.
Unless you're the Six Million Dollar Man, running in slow motion to that clicking music...that's not very fast