Depends on what kind of sports stuff you're looking for. If its specific teams, I would look at Dicks Sporting Goods or Fanz which can be found in malls, if its just sports equipment, you can look at Wal-Mart or Academy sports and outdoors
Amazon is the best ir eBay or a book shop
A Sports Shop is the nature of its self where you can buy things.
A sports shop near your house. Sports Direct
If you are going to buy an Arc trainer, going to a sports store such as Sports Authority where they have competent salespeople who really know their stuff is a good place to start.
www.brooksrunning.com/ is the best place to buy official brooks high performance sports shoes online.there are also some other places to buy sports shoes
The best CHEAP places to buy it from is Amazon and Ebay which will no doubt be secondhand but really good stuff. You can also buy it from a pawn shop or a jewellers.
sports shop such as Intersport
in a sports shop
best buy is blue, future shop is red!
Stats/Store/Stuff
Complete all of Murray's quests and then there is the shop you can buy stuff in...
in your local sports shop