I did my first runDisney race alone, although not by intention, and it was a fantastic experience. It didn't feel awkward at all. I had signed up with a friend and was planning to run with her, but I ended up with a hip issue that dictated I walk instead of run. We did the corral thing together, but as soon was we crossed the start line, she started running, and I started walking. There is so much going on around you at these races that it's not boring to be on your own at all. And as others have said, for the most part, the other racers are super friendly. I've since recruited a friend to walk the 1/2s with me, and I will say that I prefer the companionship of doing the races with a like-minded friend, but I would definitely be open to doing another on my own. In fact, I signed up for this year's Dark Side kind of at the last minute thinking I would be making a solo trip to WDW and doing a solo race, but at the even later last minute, my friend signed up too, so we ended up doing the trip and race together. But it never occurred to me not to do a race I wanted to do simply because I would be doing it solo.