They make treadmills for you people.

Yea, that certainly would be surprising; not surprised that you immediately moved away from Fido for your own, but next time obviously look ahead. What I do when power-walking is to always carry an umbrella; that way - with it open - you can scare, befuddle, and (hopefully) block Fido from attacking you. It sure does work on itty bitty dogs when there's no fence, but I live out in the country where everybody has big front yards, so it's easier to see unfenced-in dogs approach from much further away. Hope you twist an ankle, OP. Safe walking/ jogging! :-D

It was only a Chihuahua for Christ sake