[gettar82]

some find on YT:

here an ep of "Ranma 1/2" where Akane and Shampoo become superstrong (no muscle :'()
http://www.youtube.com/watch?v=3c6NAdoen1c
http://www.youtube.com/watch?v=miI1EqgZdDo

here some clip of "Birdy the mighty" where the protagonist is a girl with superhuman abilities

http://www.youtube.com/results?search_query=birdy+mighty&search=

here clips from OAV "Maris the supergal" …title say everything 🙂 (the same author of Ranma

http://www.youtube.com/results?search_query=maris+supergal&search=

unfortunately no muscle either 🙁