*4.12. Training Safety*

Beneficial effects of cardiac rehabilitation have been demonstrated, including a significant reduction in cardiac mortality by 26–36% in patients after myocardial infarction [112]. Exercise testing and training can, however, trigger an exercise-induced cardiac response with, e.g., subsequent ischemia, complex arrhythmia, or heart failure decompensation [113]. In the light of published studies, appropriately conducted exercise training is safe. The risk of major adverse events during exercise sessions is very low, with the reported occurrence of cardiac arrest, myocardial infarction, and fatal events being 1 per 116,906, 1 per 219,970, and 1 per 752,365 patient-hours of training, respectively [114]. The highest rate of complications was observed in patients diagnosed with coronary artery disease. Furthermore, the mortality was six times higher in the case of exercise facilities without the ability to promptly manage cardiac arrest [115]. In view of the potential complications, the importance of a pre-training cardiovascular risk assessment, including detailed medical history, physical examination, and scrupulous electrocardiogram monitoring during exercise testing, can clearly be seen. Thus, it is essential to comply with a safety principle during exercise testing and training through [1,8]:


The guidelines of the American Association of Cardiovascular Prevention and Rehabilitation specify a minimum number of directly supervised sessions, depending

on the risk level, and describe a progression from continuous to intermittent ECG monitoring according to the risk level. ECG monitoring is advised only for high-risk patients, such as those who have undergone the implantation of a cardioverter-defibrillator and patients with heart failure and a history of complex arrhythmias. The European Association of Preventive Cardiology specifies the use of ECG monitoring during initial exercise training sessions and for patients with new symptoms [1,45]. Heart rate monitoring and/or the Borg Rating of Perceived Exertion Scale are frequently recommended, along with the observation of signs and symptoms, such as significant fatigue, chest pain, or dizziness [16]. Exercise sessions should be terminated if the patient feels unwell, experiences the symptoms mentioned above, if complex arrhythmia or significant ischemia is recorded in ECG, or in the case of an excessive increase in heart rate or blood pressure. Exercise intensity should be reduced if the training heart rate significantly exceeds the programmed value. Specific symptoms may relate to an excessive volume of exercise and typically include persistent fatigue, sleeplessness, or muscle cramps. Therefore, patients should be notified about the potential side-effects of exercise and should notify staff if present. Training safety also depends on having an adequate staff-to-patient ratio. The ratio of 1 exercise specialist to 5–10 low- or intermediate-risk patients/session is suggested as optimal, as is 1 professional to 2–3 high-risk patients. In the case of medical emergencies, trained staff should be immediately available and with adequate equipment to respond [1,116].

### **References**


of the European Association of Preventive Cardiology. *Eur. J. Prev. Cardiol.* **2020**, *30*, 2047487320913379. [CrossRef] [PubMed]


from the Cardiac Rehabilitation Section of the European Association of Cardiovascular Prevention and Rehabilitation. *Eur. J. Cardiovasc. Prev. Rehabil.* **2010**, *17*, 1–17. [CrossRef] [PubMed]


intensity? A randomized controlled trial. *BMC Sports Sci. Med. Rehabil.* **2015**, *7*, 16. [CrossRef] [PubMed]


aerobic interval training versus moderate continuous training in heart failure patients: A randomized study. *Circulation* **2007**, *115*, 3086–3094. [CrossRef]


capacity in patients with coronary artery disease: The saintex-cad study. *Int. J. Cardiol.* **2015**, *179*, 203–210. [CrossRef]

