I wonder why this tactic hasn't been tried yet. An elite runner, mayb emiddle-distance would only have to run around the edge of the octagon, just fast enough to keep his distance from his opponent. After 1 or 2 rounds of this, most UFC fighters would be exhausted and easy to finish off, even with a runner with basic MMA skills.
The closest I've seen this tactic employed was Brock Larson vs Melvin Maenhoff.
I'm thinking Jakob because he has a good frame and knows how to throw elbows. Also 5 minutes of running per round equates to his 2000m pace. How many UFC fasters could sprint faster than Jakob's 2000m pace?