Im new here and got a few questions
depending on how many days a week.u do it... if it's 4 to 5, by 2 months u will notice a change...
I suggest running six days a week and having one rest day if you're up to that much cardio. I know I always have difficulty keeping a tight schedule like that but you should certainly feel some change within a few weeks I'd presume. It's all about repetition when it comes to endurance