VOA慢速英语:Study: Fitness Trackers Accurate for Heart Rate, Not Calories

fitness tracker - n. a wearable device or a computer application that records a person’s daily physical activity, together with other data relating to their fitness or health, such as the number of calories burned, heart rate, etc.

accurate - adj. able to produce results that are correct

calorie ​- n. a unit of heat used to indicate the amount of energy that foods will produce in the human body

stationary ​- adj. not moving : staying in one place or position

error ​- n. something that is not correct

profile ​- n. a brief written description that provides information about someone or something