The emergence of wearable devices based on advances in MEMS and low-energy technologies makes low-cost sustained physiological monitoring possible and brings health care into a new territory. But until now, most wearable devices for physiological monitoring do not have FDA approval and the measured data may have some level of noise. In this work, to understand the feasibility of applying wearable electrocardiograph for heart activity monitoring during jogging, we propose a jogging monitoring system based on wearable devices and provide some experimental results. First, the proposed jogging monitoring system is sketched. Next, the traditional ECG tests and the fundamental ECG morphology are introduced. And then, a QRS detection algorithm is introduced and implemented to process ECG data. Last, we collect ECG data by a wearable device in jogging, and some MLII lead ECG records from the MIT-BIH database are selected for comparison. The accuracy of the implemented QRS detection algorithm against both data sets is provided.