I have an ultrarunner friend (200 mile races). He told me, a good ultra-pace is 15 min/mile, as that's easily maintained for days. (Ultras are usually 24 hours a day.) At a 7 min/mile pace, you wouldn't make 200 miles. 26 for a marathon maybe, but not 200. Personally I prefer hiking to running. See you later I'm heading for the trails now. Uphill it is!