City of Sin (The Vegas Men Series Book 2) by Mia Ford

Noah owns a workout center, but keeps to his rule of not mixing business with pleasure. He can check out his customers, but he promises himself to not date one. Mia and her friend have signed up for a marathon. She is scared to death, now she has to start training. They sign up for a gym and the man who signs them up is the hottest person she has ever seen. But having her heart broken in the past she is reluctant to hope things can go someplace. This is a great story about no matter what we have in our minds of what will happen in our lives, if we finally listen to our heart things will work out in the end.