Also, when looking at groups, what you think is a fast, experienced group often is a mix of both very experienced and new people, with most being somewhere in the middle. Most are happy to take new athletes under their wing. Don't feel like you are 'slowing down' others. More often than not, they are not only willing but excited to see new faces out there, and to them, a mile at 13 mph is just as far as a millet 19 mph.