In an aspect, a sports ball includes a core including a negative Poisson's ratio (NPR) foam material, in which the core has a Poisson's ratio of between 0 and −1, and in which the NPR foam material includes an NPR polymer foam; and a cover layer surrounding the core. In an aspect, a golf club includes an elongated shaft; a grip disposed at a first end of the elongated shaft; and a head connected to a second end of the elongated shaft, the head having a flat face configured for contact with a golf ball, in which the flat face is formed of a negative Poisson's ratio (NPR) foam material, in which the head has a Poisson's ratio of between 0 and −1, and in which the NPR foam material includes an NPR metal foam, an NPR ceramic foam, or an NPR-PPR composite foam.

An exercise apparatus configured to combat postural maladaptations is provided. The exercise apparatus includes a rigid central spherical body having a channel passing through the center thereof through which a resilient band may be passed. The resilient band is removable and may be made of any suitable resilient material, such as, for example, a rubber material. The central spherical body may be formed of any suitable rigid or semi-rigid material that resists deformation.

A training system includes apparel and balls that fasten to the apparel. The apparel includes patches or strips of hook/loop fastener material that couples to strips of the hook/loop fastener material on the balls. The balls are removed during training by an opponent. The balls are placed on the apparel to emphasize training to that region.

An elastic solid ball structure of the present invention includes at least a thermoplastic polyurethane foam sphere center and a first adhesive layer, a first spherical lamina, a second adhesive layer, and a second spherical lamina sequentially disposed on the external surface of the thermoplastic polyurethane foam sphere center. The overall diameter of the elastic solid ball structure is 8 cm-26 cm. In addition, at least one protruding portion or at least one indentation portion is formed on the external surface of the thermoplastic polyurethane foam sphere center, thereby forming an irregular circular surface thereon. The described structural design provides the elastic solid ball structure of the present invention with advantages including good elasticity, a long serviceable life, permanently dispensing with the need to inflate, and eliminating having to re-inflate the ball structure.

Golf balls having a multi-layered core made of a foamed composition are provided. The core assembly preferably includes a foam inner core (center) and surrounding outer core layer. Preferably, a polyurethane foam composition is used to form the foam center. The core layers have different hardness gradients and specific gravity values. The foamed inner core assembly includes a geometric center, outer surface (skin), and thermal barrier layer that helps protect the foamed center region from the negative effects of high temperatures used during the ball-manufacturing process. Non-foamed thermoset materials such as polybutadiene rubber may be used to form the thermal barrier layer. The foam cores have good resiliency, thermal stability, and durability over a wide temperature range. The ball further includes a cover that may be multi-layered.

A toy ball is disclosed. In preferred embodiments, the toy balls comprise a ball with a hollow interior wherein the ball has a minimum diameter of fifteen inches or greater; and a pocket coupled to the ball wherein the pocket includes an opening sized to accept a human hand.

An arrow golf system has a bow having a bowstring, an arrow having a shaft with a ball on one end with a fletching and a string nock on an opposite end, a starting location, a finishing location, and a capturing apparatus at the finishing location. A player shoots the arrow from the starting location with the bow, to a second location closer to the finishing location, retrieves the arrow at the second location, and shoots the arrow toward the capturing apparatus from the second location.

An arrow golf system has a bow having a bowstring, an arrow having a shaft with a ball on one end with a fletching and a string nock on an opposite end, a starting location, a finishing location, and a capturing apparatus at the finishing location. A player shoots the arrow from the starting location with the bow, to a second location closer to the finishing location, retrieves the arrow at the second location, and shoots the arrow toward the capturing apparatus from the second location.

Closed cell foam articles, such as sports balls, and related manufacturing methods are disclosed herein. The article includes a main body made of closed-cell elastomeric resin foam having a density ranging between about 0.050 sg and about 0.800 sg after curing. Some articles are assembled by inserting a cured core into a main body so that the core is secured in the main body via an interference fit, and the core has one or more portions extending to the exterior surface of the main body such that the an exposed surface of the one or more exposed portions of the core blend substantially with the exterior surface of the main body.

A smart ball (100) comprising: an inner sphere portion (12) consisting of a cork like material and an outer sphere (19) that ensconces said inner sphere, said inner sphere further comprising: a cylindrical cavity (14), located substantially at the core of said ball, said cavity formed by drilling into said cork from an operative top side; a sensor assembly (16) placed in the centre of said cylindrical cavity along a reference plane defined by a locus of points wherein said points being collinear points running from a first end of said seam (18) to a second end of said seam, thereby ensuring that orthogonal measurements of said sensor assembly being aligned with orthogonal axes of said ball; and a charging port on said seam, said charging port connected to a battery placed in said cylindrical cavity and said battery connected to said sensor assembly.