The Altra HIIT XT is Altra's first crosstrainer, the new shape of Fit4Her strength. Designed with CrossFit and HIIT workouts in mind, it features a wrap-around, sticky rubber midsole for rope climbing and lateral traction. More cross-training specific features include the removable insole—without it the stack height goes from 24mm to 18mm—stitch ‘n’ turn stitching underfoot for a comfortable fit with or without the insole, and the stylish, durable upper. This Fit4Her shoe is built to perform with you in and out of the gym, and is so comfortable that you will want to wear it all day.