PT - JOURNAL ARTICLE AU - Manisha Gandhi AU - Honey Thomas TI - Symptomatic second-degree atrioventricular block in a recreational athlete AID - 10.1136/bcr-2021-246333 DP - 2021 Dec 01 TA - BMJ Case Reports PG - e246333 VI - 14 IP - 12 4099 - http://casereports.bmj.com/content/14/12/e246333.short 4100 - http://casereports.bmj.com/content/14/12/e246333.full SO - BMJ Case Reports2021 Dec 01; 14 AB - This case study provides an example of bradycardia associated with an increase in exercise training in a recreational athlete. Although recognised among high-level endurance athletes, this case demonstrates the potential negative effects of exercise on the heart in a patient participating in the levels of exercise recommended by Public Health England. It adds weight to the ongoing discussion of the incomplete understanding of the level of exercise needed to induce pathological changes in cardiac physiology. We discuss the investigations that led us to our diagnosis, highlighting the importance of a detailed exercise history in patients who present with palpitations and provide a potential explanation of how this phenomenon may have occurred. Currently, bradycardia induced by exercise has been managed through pacemaker insertion or complete cessation of exercise. This report demonstrates effective treatment through a period of exercise cessation and slow reintroduction of exercise training.