Abstract: Ear buds may have sensors to gather orientation information such as accelerometer measurements during user movements. A host electronic device may communicate wirelessly with the ear buds and may form part of an ear bud system that supplies the user with coaching and feedback while evaluating user performance of a head movement routine or other exercise routine. During operation, the ear buds may gather accelerometer data in a first reference frame such as a reference frame associated with the ear buds and may use a rotation matrix to rotate the data in the first reference frame into a second reference frame such as a neutral reference frame with a fixed orientation to the earth. The data in the neutral reference frame may be analyzed using a user head pose look-up table to categorize measured user head positions as corresponding to respective user head poses.

Abstract: Embodiments are disclosed for an electrical bicycle detector for energy expenditure estimation. In an embodiment, a method comprises: determining heart rate energy expenditure of a user wearing or holding the device; determining work rate energy expenditure of a user wearing or holding the device; determining a probability that the user is riding an electrical bike based on the heart rate energy expenditure and the work rate energy expenditure; determining whether or not the probability meets a condition corresponding to a threshold probability; and in accordance with the probability meeting the condition corresponding to the threshold probability: adjusting the work rate energy expenditure; and generating fitness data based at least on the adjusted work rate energy expenditure.

Abstract: Ear buds may have sensors to gather orientation information such as accelerometer measurements during user movements. A host electronic device may communicate wirelessly with the ear buds and may form part of an ear bud system that supplies the user with coaching and feedback while evaluating user performance of a head movement routine or other exercise routine. During operation, the ear buds may gather accelerometer data in a first reference frame such as a reference frame associated with the ear buds and may use a rotation matrix to rotate the data in the first reference frame into a second reference frame such as a neutral reference frame with a fixed orientation to the earth. The data in the neutral reference frame may be analyzed using a user head pose look-up table to categorize measured user head positions as corresponding to respective user head poses.

Abstract: Ear buds may have sensors to gather orientation information such as accelerometer measurements during user movements. A host electronic device may communicate wirelessly with the ear buds and may form part of an ear bud system that supplies the user with coaching and feedback while evaluating user performance of a head movement routine or other exercise routine. During operation, the ear buds may gather accelerometer data in a first reference frame such as a reference frame associated with the ear buds and may use a rotation matrix to rotate the data in the first reference frame into a second reference frame such as a neutral reference frame with a fixed orientation to the earth. The data in the neutral reference frame may be analyzed using a user head pose look-up table to categorize measured user head positions as corresponding to respective user head poses.

Abstract: A system and method for collecting motion data using a fitness tracking device located on an arm of a user, detecting that the arm is constrained based on the motion data, estimating a stride length of the user based on the motion data and historical step cadence-to-stride length data, calculating fitness data using the estimated stride length, and outputting the fitness data to the user.

Abstract: Ear buds may have sensors to gather orientation information such as accelerometer measurements during user movements. A host electronic device may communicate wirelessly with the ear buds and may form part of an ear bud system that supplies the user with coaching and feedback while evaluating user performance of a head movement routine or other exercise routine. During operation, the ear buds may gather accelerometer data in a first reference frame such as a reference frame associated with the ear buds and may use a rotation matrix to rotate the data in the first reference frame into a second reference frame such as a neutral reference frame with a fixed orientation to the earth. The data in the neutral reference frame may be analyzed using a user head pose look-up table to categorize measured user head positions as corresponding to respective user head poses.

Abstract: Ear buds may have sensors to gather orientation information such as accelerometer measurements during user movements. A host electronic device may communicate wirelessly with the ear buds and may form part of an ear bud system that supplies the user with coaching and feedback while evaluating user performance of a head movement routine or other exercise routine. During operation, the ear buds may gather accelerometer data in a first reference frame such as a reference frame associated with the ear buds and may use a rotation matrix to rotate the data in the first reference frame into a second reference frame such as a neutral reference frame with a fixed orientation to the earth. The data in the neutral reference frame may be analyzed using a user head pose look-up table to categorize measured user head positions as corresponding to respective user head poses.

Abstract: Ear buds may have sensors to gather orientation information such as accelerometer measurements during user movements. A host electronic device may communicate wirelessly with the ear buds and may form part of an ear bud system that supplies the user with coaching and feedback while evaluating user performance of a head movement routine or other exercise routine. During operation, the ear buds may gather accelerometer data in a first reference frame such as a reference frame associated with the ear buds and may use a rotation matrix to rotate the data in the first reference frame into a second reference frame such as a neutral reference frame with a fixed orientation to the earth. The data in the neutral reference frame may be analyzed using a user head pose look-up table to categorize measured user head positions as corresponding to respective user head poses.

Abstract: Ear buds may have sensors to gather orientation information such as accelerometer measurements during user movements. A host electronic device may communicate wirelessly with the ear buds and may form part of an ear bud system that supplies the user with coaching and feedback while evaluating user performance of a head movement routine or other exercise routine. During operation, the ear buds may gather accelerometer data in a first reference frame such as a reference frame associated with the ear buds and may use a rotation matrix to rotate the data in the first reference frame into a second reference frame such as a neutral reference frame with a fixed orientation to the earth. The data in the neutral reference frame may be analyzed using a user head pose look-up table to categorize measured user head positions as corresponding to respective user head poses.

Abstract: A system and method for collecting motion data using a fitness tracking device located on an arm of a user, detecting that the arm is constrained based on the motion data, estimating a stride length of the user based on the motion data and historical step cadence-to-stride length data, calculating fitness data using the estimated stride length, and outputting the fitness data to the user.

Abstract: Ear buds may have sensors to gather orientation information such as accelerometer measurements during user movements. A host electronic device may communicate wirelessly with the ear buds and may form part of an ear bud system that supplies the user with coaching and feedback while evaluating user performance of a head movement routine or other exercise routine. During operation, the ear buds may gather accelerometer data in a first reference frame such as a reference frame associated with the ear buds and may use a rotation matrix to rotate the data in the first reference frame into a second reference frame such as a neutral reference frame with a fixed orientation to the earth. The data in the neutral reference frame may be analyzed using a user head pose look-up table to categorize measured user head positions as corresponding to respective user head poses.