Sports footwear comprises 3 key elements: shape, midsole and sole. The shape relates to the part of the shoe which shrouds and protects our foot. It can be based on different materials, either natural skin or synthetic fabrics, but the best suited for trail running are the man-made, due to its great resistance, flexibility, breathability and easiness to clean. Depending on the weather we can opt for waterproof membranes like GoreTex, but we really need to assess if we need it, as it pushes up the price and it’s a rather delicate layer, which requires special washing precautions in order to avoid any damage to it. The set of side strips which embrace the foot are not mere decorations, but active stabilizers whose mission is to hold our limb conveniently. The buttress is a reinforcement which usually lies on the back of the heel. Its mission is to stabilize it during the stepping fase, the most traumatic impact of the whole stride. While in the store, we should double check if it’s there and if it’s sturdy enough (it should not be bent by pressing with the fingers, as it usually happens on the instep or the sides of the shoe, the most flexible areas). The tongue is the part of the shoe that prevents the rubbing of our foot with the laces. Consequently, to fulfill its mission it needs to be sufficiently padded. Some include a small pocket on the top, which serves as a hold for the bowknot, preventing them to become untied and entangled with a protruding obstacle while on the move. Likewise, some laces need not to be tied but retracted with a plastic clip, hence preventing them to unloose.