Abstract: The present disclosure relates to methods and systems of determining swimming metrics of a user during a swimming session. The method can include receiving, by a processor circuit of a user device, motion information from one or more motion sensors of the user device; determining, by the processor circuit using the motion information, a first set of rotational data of the user device, wherein the first set of rotational data is expressed in a first frame of reference; converting, by the processor circuit, the first set of rotational data into a second set of rotational data, wherein the second set of rotational data is expressed in a second frame of reference; determining, by the processor circuit, one or more swimming metrics of the user; and outputting the one or more swimming metrics.

Abstract: A method and a system for determining an energy expenditure of a user by detecting unmeasurable loads using heart rate and work rate are described. Time-stamped heart rate data and work rate data can be collected by one or more sensing modules. A processor circuit can calculate a heart rate-based energy expenditure and a work rate-based energy expenditure. The processor circuit can output a hybrid energy expenditure based on a heart rate confidence parameter, an exercise type, a fraction of heart rate reserve, and a hear rate-based metabolic equivalents of task.

Abstract: A fitness tracking device configured to be worn by a user obtains a plurality of physical characteristics of the user including a first age and a sex of the user. The fitness tracking device maps each physical characteristic of the user to a corresponding index, wherein the first age of the user is mapped to a first age index of a first age range of a plurality of age ranges, and wherein the sex of the user is mapped to a first sex index. The fitness tracking device selects, from a memory of the fitness tracking device, a first calorimetry model of a plurality of calorimetry models, wherein the first calorimetry model is associated with each corresponding index, including the first age index and the first sex index of the user. The fitness tracking device estimates an energy expenditure rate using the first calorimetry model.

Abstract: Systems and methods of analyzing a user's motion during a swimming session are described. One or more motions sensors can collect motion data of the user. A processor circuit can make motion analysis based on the motion data. The processor circuit can determine if the user's arm swing is a genuine swim stroke. The processor circuit can also determine whether the user is swimming or turning. The processor circuit can also classify the user's swim stroke style. The processor circuit can also determine the user's swim stroke phase. The processor circuit can also determine the user's stroke orbit consistency.

Abstract: The present disclosure relates to methods and systems of determining swimming metrics of a user during a swimming session. The method can include receiving, by a processor circuit of a user device, motion information from one or more motion sensors of the user device; determining, by the processor circuit using the motion information, a first set of rotational data of the user device, wherein the first set of rotational data is expressed in a first frame of reference; converting, by the processor circuit, the first set of rotational data into a second set of rotational data, wherein the second set of rotational data is expressed in a second frame of reference; determining, by the processor circuit, one or more swimming metrics of the user; and outputting the one or more swimming metrics.

Abstract: A method and a system for determining an energy expenditure of a user by detecting unmeasurable loads using heart rate and work rate are described. Time-stamped heart rate data and work rate data can be collected by one or more sensing modules. A processor circuit can calculate a heart rate-based energy expenditure and a work rate-based energy expenditure. The processor circuit can output a hybrid energy expenditure based on a heart rate confidence parameter, an exercise type, a fraction of heart rate reserve, and a hear rate-based metabolic equivalents of task.

Abstract: In one aspect, the present disclosure relates to a method including obtaining, by a fitness tracking device configured to be worn by a user, a plurality of physical characteristics of the user, wherein the plurality of physical characteristics includes a first age and a sex of the user; mapping, by the fitness tracking device, each physical characteristic of the user to a corresponding index, wherein the first age of the user is mapped to a first age index of a first age range of a plurality of age ranges, and wherein the sex of the user is mapped to a first sex index; selecting, from a memory of the fitness tracking device, a first calorimetry model of a plurality of calorimetry models, wherein the first calorimetry model is associated with each corresponding index, including the first age index and the first sex index of the user; and estimating, by the fitness tracking device, an energy expenditure rate using the first calorimetry model, wherein the fitness tracking device can include constrained resources

Abstract: In one aspect, the present disclosure relates to a method including obtaining, by a fitness tracking device, an average step count of a user of the fitness tracking device; mapping, by the fitness tracking device, the average step count to a first corresponding physical activity level of a plurality of physical activity levels; storing, in a memory of the fitness tracking device, the first corresponding physical activity level; estimating, by the fitness tracking device, an aerobic capacity of the user using the first corresponding physical activity level of the user; and estimating, by the fitness tracking device, an energy expenditure rate of the user using the aerobic capacity of the user.

Abstract: A therapy and mobility assistance system used by a patient that includes a leg device worn on the leg of the patient that provides assistance and/or resistance to enhance the mobility of the leg of the patient, a therapy shuttle that facilitates therapeutic extension and flexion of at least one of the joints of the leg of the patient, and an appendage fastener that selectively couples the therapy shuttle and the leg device. The therapy and mobility assistance system may additionally include a guide track that constrains motion of the therapy shuttle along a path.

Abstract: A therapy and mobility assistance system used by a patient that includes a leg device worn on the leg of the patient that provides assistance and/or resistance to enhance the mobility of the leg of the patient, a therapy shuttle that facilitates therapeutic extension and flexion of at least one of the joints of the leg of the patient, and an appendage fastener that selectively couples the therapy shuttle and the leg device. The therapy and mobility assistance system may additionally include a guide track that constrains motion of the therapy shuttle along a path.