Altra Black White Women's HIIT XT 2 Sneakers AFW1976P-02 US 8.5 Based on feedback, we've refined the fit, function, look and feel of the HIIT XT 2. The biggest update is the improved women's fit. In addition, the more flexible construction makes for a better running experience, while the updated lacing system and PowerSole™ insole technology means it is even more stable for lateral movements and lifting.