An exercise machine adjustable resistance system and method for efficiently varying the workout resistance for an exercise machine. The exercise machine generally includes a carriage movably positioned with respect to the at least one rail, a plurality of springs selectively connectable to the carriage to provide a resistance level to the carriage, a plurality of electrically actuated mechanical devices adapted to latch a corresponding one of the plurality of springs to the carriage when in the latch state and unlatch a corresponding one of the plurality of springs to the carriage when in the unlatch state and a control unit in communication with the plurality of electrically actuated mechanical devices to selectively control the state of each of the plurality of electrically actuated mechanical devices to be within the latch state or the unlatch state.

There is provided a limb exercise device comprising: a force sensor configured to determine a weight applied to the device; a sliding component configured to facilitate the sliding movement of the device along a separate surface, wherein the separate surface is a surface that is separate to the device, wherein the sliding component comprises a part of an external housing of the device; a device movement sensor configured to determine a movement of the device on the separate surface; a limb position sensor configured to determine a position, in at least one dimension, of a limb of a user positioned above or adjacent to the device; and an output device configured to output an indication in dependence on a signal from at least one of: the force sensor, the device movement sensor and the limb position sensor.

An adjustable ab wheel has a main shaft and two wheels mounted on the main shaft. The main shaft has two external threaded sections. Each one of the two external threaded sections has a thread direction opposite to the thread direction of the other one of the two external threaded sections. Each one of the two wheels has a threaded hole axially defined through the wheel and mounted with a respective one of the two external threaded sections. When a user rolls the two wheels forward, the two wheels approach each other and abut against each other. Abutment between the two wheels allows the two wheels to brake themselves, so that the adjustable ab wheel can prevent users from over rolling the two wheels forward and suddenly falling down to the floor.

An adjustable ab wheel has a main shaft and two wheels mounted on the main shaft. The main shaft has two external threaded sections. Each one of the two external threaded sections has a thread direction opposite to the thread direction of the other one of the two external threaded sections. Each one of the two wheels has a threaded hole axially defined through the wheel and mounted with a respective one of the two external threaded sections. When a user rolls the two wheels forward, the two wheels approach each other and abut against each other. Abutment between the two wheels allows the two wheels to brake themselves, so that the adjustable ab wheel can prevent users from over rolling the two wheels forward and suddenly falling down to the floor.

Embodiments of the present invention comprise a 4-wheeled resistance training device in the form of a box, wherein a user may add weights to the inside or to the top of the box to increase the resistance provided to the user. The wheels may be connected to the box by one or more threaded axles, each threaded axle existing as two or more parts. Rotation of the threaded axles may power a generator, which may power a light system comprising one or more lights. The light system may provide visual feedback to a user by changing the color and/or intensity of the one or more lights depending on multiple factors. Further embodiments of the invention may comprise a battery for storing energy generated by the generator. Embodiments of the invention may also comprise the ability to store data about a user's workout.

Embodiments of the present invention comprise a 4-wheeled resistance training device in the form of a box, wherein a user may add weights to the inside or to the top of the box to increase the resistance provided to the user. The wheels may be connected to the box by one or more threaded axles, each threaded axle existing as two or more parts. Rotation of the threaded axles may power a generator, which may power a light system comprising one or more lights. The light system may provide visual feedback to a user by changing the color and/or intensity of the one or more lights depending on multiple factors. Further embodiments of the invention may comprise a battery for storing energy generated by the generator. Embodiments of the invention may also comprise the ability to store data about a user's workout.

Hand-held, portable exercise device which enables the user to strengthen muscles and joints by performing various exercises, the device having a base structure defining a receptacle and supporting at least three omnidirectional rotational elements. A grip element, which may be spherical, has a lower surface positionable on the receptacle and has an upper gripping surface that is convex in at least two dimensions. A hand retaining strap is positionable over the gripping surface of the grip element such that a hand of a human user, the hand having a palm surface and a back surface, can be inserted between the retaining strap and the gripping surface, the palm surface of the user's hand contacting the gripping surface while the retaining strap contacts the back surface of the user's hand to secure the exercise device to the hand.

Hand-held, portable exercise device which enables the user to strengthen muscles and joints by performing various exercises, the device having a base structure defining a receptacle and supporting at least three omnidirectional rotational elements. A grip element, which may be spherical, has a lower surface positionable on the receptacle and has an upper gripping surface that is convex in at least two dimensions. A hand retaining strap is positionable over the gripping surface of the grip element such that a hand of a human user, the hand having a palm surface and a back surface, can be inserted between the retaining strap and the gripping surface, the palm surface of the user's hand contacting the gripping surface while the retaining strap contacts the back surface of the user's hand to secure the exercise device to the hand.

An exercise roller includes an elongated bar having grip handles arranged at opposing axial ends of the elongated bar, a cylindrical core supported by the elongated bar between the grip handles, and a cover that surrounds the cylindrical core and is formed of a material having a repeating pattern.

An exercise roller includes an elongated bar having grip handles arranged at opposing axial ends of the elongated bar, a cylindrical core supported by the elongated bar between the grip handles, and a cover that surrounds the cylindrical core and is formed of a material having a repeating pattern.