God Emporer of Dune, by Frank Herbert features Nayla, a super strong muscular woman as a major supporting character. Apparently she can lift a 100kg man with one arm...
Yeah, actually all the Fish Speaker (emperor Leto's army) were formed by amazonian women, some clearly despicted as muscular.
But anyone who reads this book without reading the first three is committing a crime of the highest order. Simply one of the best Fantasy/Sci-Fi series ever made!
Other books I recollect having muscular women are:
1- Sphere, Michael Crichton: The main biologist portrayed by Sharon Stone in the movie, was in the book a very athletic women, who the main character referred to as Mother Nature with muscles at one point.
2- Hyperion, Dan Simmons: One of the main female characters is a short but very strong woman who lived in a world with strong gravity. In one passage, she fights naked and lifts and throws a man across the room. THIS IS A VERY, VERY GOOD BOOK!!!
3- Malazan Book of The Fallen: In this amazing high fantasy series, strong women are present in many places, though not always in an explicit way. But in some armies, a lot of the heavies (armored units) are females. This is, along with A Song of Ice and Fire, one of my favorite fantasy series. It's not easy to get in to, because the author just throws you in the middle of this entire new world, but after you get in to it, you won't get out. Extremely good literature.
I'll think of other books later when I have more time.