Excercise! Move to loose today?

Yeah, I think having a serious sadistic streak is required to be a personal trainer. She keeps raising the weight when I'm not looking and "losing count" of how many reps I've done. She's also trying to get me to start running instead of walking. I've been walking about 6-8 miles and she wants me to start running about 3-4 miles instead. I don't know if my ankles are up for it though.