Abstract: A sensor is coupled to a barbell and generates data indicating motion of a barbell over time. At least one trained neural network is implemented to detect and count repetitions of an exercise performed with the barbell. The at least one trained neural network detects the repetitions based on the data generated by the sensor, and based on (a) a type of exercise performed with the barbell detected from the received data or provided as labeled data, and/or (b) an identity of a user that performed the exercise as detected from the received data or provided as labeled data.