Rarely does a week go by without a major fashion brand launching either a model-backed collab or an activewear line. Oftentimes the two converge. (See: Rosie Huntington-Whiteley for Marks & Spencer, Heidi Klum for New Balance, Behati Prinsloo for Juicy Couture.) Looking at the numbers, it’s no surprise. In the age of social media,…
