Dynamic strength loading per movement includes determining progress within a given state of an exercise. It further includes controlling, as a function of the progress within the given state of the exercise, a force generated by a motor of an exercise machine.

A computer program product, apparatus, and method may include various operations. The operations may include calibrating a sensor device to identify a heading, wherein the sensor device includes an inertial measurement unit, receiving three-dimensional motion data from the sensor device secured to a body part of a person as the person performs an activity involving movement of the body part, and causing generation of output based on the three-dimensional motion data, wherein the output is based on the movement of the sensor device.

Methods and systems for detecting configuration states of a golf club and adjustment systems of a golf club, such as a shaft connection system. A golf club configuration detection system captures configuration data from the adjustment system of the golf club by a configuration detection device, such as a camera, a barcode scanner, or an RFID scanner. The captured configuration data is compared to reference configuration data to determine a configuration state of the adjustment system. Swing data and ball-flight data are tracked for golf-ball strikes with the golf club in the detected configuration state. Recommendations for configuration states may be generated based on the tracked data.

The invention relates in general to lacrosse heads, and more particularly to preparation of a lacrosse head that is optically clear, but still maintains the desired stiffness and durability characteristics for optimal play.

An adjustable laser-sensor paired system for creating or replicating a desired swing form includes a laser device and a sensor device. The laser device has a laser which emits a laser beam and a mounting device which attaches the laser device to an object. The orientation of the laser is adjustable. The sensor device has an optical linear position sensor for detecting the laser beam of the laser device and a display with LEDs for providing feedback and user interface. With the system and method, one or more checkpoints for the form of a desired swing can be created at a selected point in the swing path, which may then be used as practice reference guides to check whether the user is correctly replicating the desired swing.

A fitness device contains a strap, a handle, and a plate. The strap is substantially inelastic and flexible. The plate is substantially rigid. The handle at least partially envelopes the strap. A method of exercising with such a fitness device is also described herein. Other fitness devices and other methods of use are also described herein.

A shaft for a golf club includes a first end, a second end, and a demarcation. The first end is adapted to attach to a club head. The second end is adapted to receive a grip distal to the first end. The demarcation is positioned at or adjacent to the balance point of the golf club between the first end and the second end.

Systems and methods for testing the accuracy of a bicycle training apparatus that is configured to measure the power output of a cyclist riding on a bicycle. The system includes a base, a main drive shaft secured to the base, a motor secured to the base and configured to rotate the main drive shaft, torque and rotational speed sensors configured to measure the torque and rotational speed of the main drive shaft during rotation thereof. The bicycle training apparatus may be secured relative to the base and functionally coupled to the main drive shaft. The motor may then be operated to apply a power input to the bicycle training apparatus while measuring the torque and rotational speed of the main drive shaft and the power input with the bicycle training apparatus. The resulting measurements may be compared to determine the accuracy of the bicycle training apparatus.

Power measurement device for a bicycle trainer, which device is built as a unitary relocatable device comprising an acceleration or velocity sensor, a microcontroller and a memory, wherein the device is equipped with or connectable to a power source, preferably a battery, and wherein the device is equipped with a communication facility to enable the device to wirelessly or through wires communicate with an external application device.