The Skechers XF series of fitness walkers are designed to provide a low-intensity workout for all-day wear. The specially designed two part, multi-density midsole delivers a moderate rocking effect as you walk. The softer, lower layer provides superior cushioning and creates natural instability. This helps activate muscles, and take pressure of your joints and back. The XF series is especially recommended as a "beginners" toning shoe as it doesn't require the same acclimation process as models with more intense rocker soles. This group of footwear receives a 2 out 5 on the Skechers "Burn Meter".