Make sure to note that she assaulted you at multiple places in the gym. "If it were only at the treadmill, it wouldn't be so bad, because I'd know to just avoid that area [ * ] but she did it near the exit too. I can't get away from her harassment!" [ * ] not that you should have to, but just to make it sound like you are somewhat reasonable and don't want to make a fuss. It's also the kind of language victims often use.