Shoe

1. A shoe with an internal side and an external side comprising:

a sole comprising a first side configured to face the ground, and a second side facing the opposite side;

an intermediate sole disposed onto the sole; said intermediate sole having a length and a minimum width in a central portion of the intermediate sole, the intermediate sole having a rigid portion configured to extend from a forefoot to a heel and to sustain an arch support without following a movement of a user's foot during walking;

an upper joined to the intermediate sole; and

a reinforcement insert joined with the intermediate sole, said reinforcement insert comprising:

a central longitudinal portion configured to extend between the heel and a toe of a user's foot, which is configured to interface with a plantar surface of the user's foot,

an internal lateral wing tilted upwards and disposed on the internal side of the shoe, said internal lateral wing being provided with a profile that is configured to interface and to conjugate with a medial longitudinal arch of a foot sole, characterized in that a ratio between the length and the minimum width of the intermediate sole is higher than 8.3, and the minimum width of the intermediate sole is lower than 3 cm for a shoe configured to fit the user's foot when the user's foot has a length between 24.5 cm and 25.5 cm, and

an external lateral wing provided with a profile that is configured to interface and to conjugate with a lateral longitudinal arch of the foot sole, wherein said internal lateral wing and external lateral wing of the reinforcement insert are configured to give a rigid arch support to the user's foot.

2. The shoe of claim 1 , wherein said reinforcement insert comprises a concave front edge with concavity configured to face the toe of the user's foot, so that when the reinforcement insert being pushed by the user's foot during walking, the reinforcement insert can bend more in said concave front edge, consequently separating the internal lateral wing from the external lateral wing, which are configured to dynamically follow the medial longitudinal arch and the lateral longitudinal arch of the foot sole, when the foot is rolling, and provide a rigid support as soon as the user's weight is statically discharged on the shoe.

3. The shoe of claim 2 , wherein said intermediate sole comprises a flexible portion in the forefoot configured to extend from the forefoot to the toe of the user's foot, and joined to the rigid portion.

4. The shoe of claim 1 , wherein said reinforcement insert is made of carbon or fiber composite materials.

5. The shoe of claim 1 , wherein said ratio between the length and the minimum width of the intermediate sole is comprised between 10 and 15.

6. The shoe of claim 1 , wherein:

at least one of the external lateral wing or the internal lateral wing of said reinforcement insert has an upper curvilinear edge with downward-facing concavity; and

said upper curvilinear edge of said at least one of the external lateral wing or the internal lateral wing being provided with a first end and a second end and being joined at the first and second ends with the central longitudinal portion.

7. The shoe of claim 1 , wherein said reinforcement insert has a differentiated rigidity.

8. The shoe of claim 1 , comprising a heel with an upper end joined to the intermediate sole and a lower end adapted to come in contact with the ground, wherein said reinforcement insert is configured to extend from the heel to a metatarsus of the user's foot.

9. The shoe of claim 1 , wherein said reinforcement insert comprises a concave back edge with concavity configured to face the heel.

10. The shoe of claim 1 , wherein said reinforcement insert is integrated in the intermediate sole by means of welding or gluing.

11. The shoe of claim 1 , wherein said reinforcement insert is interposed between the intermediate sole and the sole.