15 mins/mile is the pace I tried to hold w/ my wife during a walking workout today. We went to Duke and did the Al Buehler trail. The AB trail is really beautiful. Its about 3 miles long and goes up and down, up and down, up.... As one can guess its one hilly course.
We finished in 43:03. She dropped me on the last hill. That was kinda humbling since I just did an IM. I've got a whole new level of respect for walking workouts. Since I'm on some down time from workouts, it has been great hanging out w/ the missus and participating w/ her excersing.