Of course, runners naturally have great legs. For example:
http://www.mensracing.com/photos/pennrelays03/penn58.jpg
http://www.mensracing.com/photos/bigeast03/be06.jpg
http://www.mensracing.com/photos/bigeast03/be203.jpg
http://www.mensracing.com/photos/usaindoor03/usin15.jpg
http://www.mensracing.com/photos/usaindoor03/usin45.jpg
There are lots more men's racing galleries here:
www.mensracing.com - Photos
http://www.mensracing.com/photos/pennrelays03/penn58.jpg
http://www.mensracing.com/photos/bigeast03/be06.jpg
http://www.mensracing.com/photos/bigeast03/be203.jpg
http://www.mensracing.com/photos/usaindoor03/usin15.jpg
http://www.mensracing.com/photos/usaindoor03/usin45.jpg
There are lots more men's racing galleries here:
www.mensracing.com - Photos