Complex sentence: Mad Dogg Athletics is gaining a reputation for trying to aggressively enforce their trademarks around the globe despite many doubts about validity of their word trademark "spinning" which is considered as a generic word for indoor cycling in some parts of the world.
Split into simpler sentences: Mad Dogg Athletics is gaining a reputation for trying to aggressively enforce their trademarks around the globe. The trademarked word "spinning" is considered as a generic word for indoor cycling in some parts of the world.