I cannot imagine how terrifying this must have been! A guy in Utah was going for a run when he realized he was being stalked by a mountain lion. Thankfully she got startled and eventually ran away.
If you ever find yourself in this situation, try to stay calm. Back away slowly, maintain eye contact, make yourself BIG by standing up tall, talk loudly and firmly and FIGHT BACK if attacked!
WARNING: VIDEO CONTAINS PROFANITY