fitness tracker
noun [ C ] uk/ˈfɪt.nəs ˌtræk.ər/ us/ˈfɪt.nəs ˌtræk.ɚ/
（通常戴在手腕上，记录身体状况和活动情况，例如心率和走了多少步的）智能健身表
an electronic device, usually worn on the wrist, that is designed to record information about your physical fitness and activity, for example your heart rate and how many steps you have walked