Nike Free Metcon 4 combines the flexibility of Nike Free on the forefoot with the stability of Metcon on the heel to give his best in the training session. Nike free technology on the forefoot offers maximum flexibility for agile movements and shots. The rigidity on the sides supports the lateral movements. The large and flat heel provides a stable base for weight lifting. The softer foam core amortizes the foot, while the most rigid external layer offers resistance and support.