Embodiments of golf club heads, golf clubs, and methods to manufacture golf club heads and golf clubs are generally described herein. In one example, a golf club head may include a body portion, and an internal mass portion comprising a material having a greater density than a material of the body portion, a height in a top-to-sole direction, a depth in a front-to-back direction, and a width in a toe-to-heel direction. The distance between the internal mass portion and a toe portion edge is substantially less than the distance between the internal mass portion and a heel portion edge. The volume of the internal mass portion increases in a top-to-sole direction, and the height of the internal mass portion is greater than the width of the internal mass portion. Other examples and embodiments may be described and claimed.

A head guard is provided. The head guard includes one or more sensors as part of an sensory input and communications system. The head guard wirelessly communicates data to remote computing devices for intelligent data collection.

Sleeves for improving performance and control are disclosed. The sleeves are constructed for use on the fingers, wherein each sleeve is constructed in some embodiments with grip zones that match areas of the finger to ensure improved grip while maintaining flexibility, compression, protection, and material durability. Each grip zone is positioned to ensure that fingers are able to naturally bend without impeding grip performance. A spine on a rear of the sleeve ensures material durability, limits over extension, and provides padding and protection.

Disclosed herein is a casting cluster for casting a body of a golf club head made of titanium or a titanium alloy. The casting cluster comprises a receptor and a plurality of runners coupled to the receptor and configured to receive molten metal from the receptor. The casting cluster also includes at least forty main gates. At least two of the main gates are coupled to each of the runners and each main gate is configured to receive molten metal from a corresponding one of the plurality of runners. The casting cluster further comprises at least forty molds. Each mold of the at least forty molds is configured to receive molten metal from a corresponding one of the main gates and to cast a body of an iron-type golf club head.

Disclosed herein is an iron-type golf club head that comprises a body, made of a first material having a first density. The iron-type golf club head also comprises a weight located within the internal cavity. The iron-type golf club head further comprises a filler material that has a density no less than 0.21 g/cc. The filler material has a mass no less than 2.5 grams and no more than 8 grams. The internal cavity has an internal cavity volume ranging between 5 cc to 20 cc. A ratio of the internal cavity volume to external club head volume ranges between 0.14 and 0.385. The internal cavity has a minimum front-to-back depth above a midplane of the golf club head of no less than 1.4 mm and a maximum front-to-back depth of the internal cavity above the midplane of the golf club head is no more than 13 mm.

A treadmill may include two separate left and right belts rotating around two sets of rollers, four legs having an adjustable height via air suspension to customize an inclination of the treadmill, a thermoelectric assembly, a fragrance assembly having a rotating fragrance cartridge to emit various smells toward a user of the treadmill, a display on which exercise programs are played, and an attachment module having a dispensing tray on which treats are dispensed. A handle of the treadmill may have a sensor to sense a height and front-rear position, and a belt divider provided between the left and right belts may have position or proximity sensors to sense a left-right position. An inclination of the treadmill may be automatically adjusted according to positions detected by the sensors, and the fragrance assembly, attachment module, and inclination may be automatically operated in accordance with an exercise program played on the display.

An exercise apparatus is provided. The exercise apparatus includes first and second base assemblies, each having a plurality of riser segments. A first rail is connected to and spans the first and second base assemblies. The first rail has a plurality of horizontal segments interspersed with a plurality of vertical segments. A second rail is spaced apart from the first rail and is connected to and spans the first and second base assemblies. The second rail has a plurality of horizontal segments interspersed with a plurality of vertical segments. The horizontal and vertical segments of the second rail correspond to the horizontal and vertical segments of the first rail. Adjacent horizontal segments of each of the first and second rails are vertically spaced apart.

It has been found that carboxylic acid functionalized high cis-1,4-polybutadiene rubber which is comprised of polybutadiene rubber chains having a cis-1,4-microstructure content of at least 90 percent has much better interaction with metal salts of α,β-ethylenically unsaturated carboxylic acids, such as zinc diacrylate or zinc dimethacrylate. This results in such rubber compositions being stiff while still exhibiting a lower level of hysteresis. These characteristics are beneficial when used in manufacturing tire apex compositions, in manufacturing golf ball cores, and in a wide variety of other applications. Such rubber compositions can be used as substitutes for thermoplastic elastomers in many applications.

A mouthguard according to an embodiment of the present disclosure includes a pair of spaced lateral bite wings, a conduit defining an air channel extending between forward portions of the lateral bite wings, and a lip shield member and/or a flange disposed around and extending radially outward with respect to a forward end of the conduit. The conduit is tapered inward from its forward end toward its rearward end, and defines an incisor engaging surface proximate the rearward end of the conduit, and a lip engaging surface between the incisor engaging surface and the forward end of the conduit.

Some embodiments include club heads having reinforced club head faces. In one example, the club face comprises a reinforcement element such as a looped rib positioned on a rear surface of the club face to provide reinforcement. The club head further comprises an undercut that extends along the entire perimeter of the club face to provide increased club face bending. The combination of the reinforcement element and the undercut reinforces the club head while permitting the club face to bend. Other embodiments of related club heads and methods are also disclosed.