Yes. My friends have done that before, though they usually just walk around town. It's VERY dangerous. DXM
increases your heart rate and blood pressure a shit ton, and so does running. Be VERY careful when mixing the two, please.
However, my friends do agree that walking / running is incredible. They've done it mostly on doses between 900-1200mg, and it feels like their legs are pure goop absorbing the shock of every step... absolutely incredible. But do NOT underestimate the potential for a stroke or heart attack, it's very dangerous territory.