Abstract: A helmet for sporting activities. The helmet includes an outer shell and a lower portion, the outer shell designed to be positioned on a skull, the outer shell including an upper portion to cover at least the crown portion of the skull, the material forming the upper portion having mechanical properties suitable for the upper portion to satisfy a certification standard defined for the intended use of the helmet. The lower portion is affixed to the upper portion so as to form a single unitary element, the lower portion extending continuously so as to at least partially cover the lateral portions and rear portion of the skull, the lower portion being made of a material having a different modulus of elasticity than that of the material forming the upper portion.