There have been many discussions on this board about running inside vs outside. I suggest doing a search and finding a lot of information that way.
From what I've read and experienced personally, most people find the transition difficult. If you start outside, they hate the treadmill and vice versa. That doesn't mean you can't make the switch, you just have to stick with it.
I highly recommend developing a love of outdoor running because it's where you'll run if you decide to race and the outdoors will always be available while a treadmill might not be. Some suggestions: music, podcasts, run apps, audio books, a running partner or group, taking your dog (or borrowing a friend's), prayer, meditation, focusing on your breathing and form, checking out new routes, enjoying the scenery.
What has worked for me: I mix it up between podcasts and running with a partner (my husband). I run three times a week, twice near my home and once at a nearby park. Whenever I go on vacation, I make it a point to run where I'm at.
| Pounds lost: 68.4