A resilient rod that provides adjustable directional resistance is disclosed. In one aspect of the invention, a resistance level may be determined based on a thickness of the rod and a position of an applied force with respect to a fulcrum point. In another aspect of the invention, at least one spine may be attached to the beam to increase a diameter of the beam along one axis. The resistance level may be determined based on the thickness of the rod, the position of the applied force and an orientation of the at least one spine with regard to the direction of the applied force. In other aspects of the invention, the resilient rods may be incorporated into a golf club that provides for adjustable resistance levels.

Exercise mats, systems of exercise mats, and related methods of making and/or using the same are provided herein. More specifically, the subject matter disclosed herein relates to exercise mats, such as yoga mats, and systems of exercise mats that provide visual cues and/or different levels of tackiness to provide different levels of grip to optimize a user's connection to the mat and methods related to the exercise mats.

A ball striking device, such as a golf club head, includes a face having a ball striking surface, an inner surface opposite the ball striking surface, and a thickness defined between the ball striking surface and the inner surface, and a body connected to the face and extending rearward from the face. The face has a modulus gradient across the thickness of the face, such that the modulus of the face varies at different distances from the ball striking surface. The face may also include at least one of an insert, a composite material, a multi-layered structure, and/or a portion treated by a surface treatment to contribute to the modulus gradient.

An exercise bike includes a frame, a rotor assembly and a drive assembly mounted on the frame, where the drive assembly is configured to drive rotation of the rotor assembly, and a cover configured to at least partially cover the rotor assembly. The components of the drive assembly and the rotor assembly include structures that improve the performance of the exercise bike, including but not limited to a strong and rigid construction and improvements in belt tracking, user feel, effort consistency, synchronization, and rotor performance.

Method for coupling a sensor to a piece of equipment, such as a golf club, baseball bat, or tennis racket, that ensures that the sensor is in a known position and orientation relative to the equipment. Compensates and calibrates for degrees of freedom introduced in manufacturing and installation. The method may include manufacturing a sensor receiver that aligns with equipment in a fixed orientation, and that holds a sensor housing in a fixed orientation relative to the receiver. Remaining uncertainties in sensor position and orientation may be addressed using post-installation calibration. Calibration may include performing specific calibration movements with the equipment and analyzing the sensor data collected during these calibration movements.

Disclosed herein is a golf club head that comprises a body. The body comprises a sole portion, a crown portion, a skirt portion, and a face portion, positioned at a forward region of the golf club head, opposite a rearward region of the golf club head, and extending from a toe region to a heel region of the golf club head. At least a portion of the body is made of a titanium alloy. The golf club head also comprises a large weight, coupled to the sole portion of the body and made of a steel alloy. A mass of the large weight is at least 40% of a mass of the portion of the body made of the titanium alloy. A total mass of the large weight and the portion of the body made of the titanium alloy is at least 210 grams.

An inflatable plyometric box having a first inflatable member adapted to be inflated to a pressure, a second inflatable member on top of the first inflatable member and adapted to be inflated to a pressure, and a connecting member connected to the first inflatable member and the second inflatable member which secures the first inflatable member to the second inflatable member. The first and second inflatable members incorporate drop stitch technology which provides substantial rigidity to first and second inflatable members when the first and second inflatable members are inflated to the pressures. Thus the inflatable plyometric box is substantially rigid to support a user landing on the top of the inflatable plyometric box. The inflatable plyometric box may include a stabilizing member which may be connected to the bottom of the inflatable plyometric box, wherein the stabilizing member is adapted to increase the stability of the inflatable plyometric box.

A tennis ball including a spherical core. The spherical core including an outer surface and a raised wall integrally molded as part of the outer surface.

An exercise accessory includes a load bearing element. It further includes a haptic actuator. In response to an indication of an event pertaining to a load on the load bearing element, the haptic actuator is configured to generate a vibration pattern corresponding to the event. Different events are associated with different vibration patterns.

A golf club head enables the initial velocity of a ball to be increased and enables the carry to be lengthened. In some example structures, the golf club includes a face plate formed from metal and club head body (e.g., a crown and sole) formed from fiber reinforced plastic. A weighted body is provided inside the rearmost portion of the golf club head and a low rigidity portion whose width becomes gradually narrower as it approaches the rearmost portion is provided in the crown extending from the vicinity of the face plate to the rearmost portion.