@jessicaolin - Back when the family had a little cairn terrier (in the 1980s), I'd try to take her on walks, and she would run faster than I could walk, and eventually tear up her paw pads scrabbling the sidewalk.
So one day, I held her leash tight to keep her from lunging forward on our walk, got on my bike, and let her go. She could really get a run going even pulling me along on that bike. :)