Amazon isn't just for buying books and slow cookers. Their fashion section is so much better than you think—you can find endless activewear items, yoga pants, shoes, sports bras, etc, and a lot of the most popular brands, all with Prime shipping. The real beauty of Amazon is customer reviews and customer selfies, so you'll know exactly what you're getting before you buy. And if you don't like it, Amazon basically has a no-hassle, no-questions asked return policy.