I. Introduction
High levels of training or high-performance sports entail a high degree of stress for the human heart that could lead to abnormal behavior in some athletes. For these reasons, monitoring the heart profile during sports competitions or high-level physical activities might diagnose pathologies and prevent possible injuries. Wearable mHealth—mobile health—solutions based on the use of smartphones or other portable devices [1] have been adopted in this context to improve prevention, diagnosis, treatment, monitoring, and management of health and lifestyle [2]. In particular, mHealth applications represent an interesting low-cost solution for monitoring cardiac conditions during sport competitions [3], [4].