The evidence supporting the beneficial effects of physical activity on health is compelling. Regular exercise reduces cardiovascular mortality by 35 % and all-cause mortality by 33 %1 and confers an average of 7 years greater longevity.2 Most professional athletes, however, undertake doses of exercise that far exceed those recommended by the current evidence, which has been adopted by national and international health authorities. This is of relevance, as recently published data suggest that, similar to most pharmacological interventions, exercise has an optimal dose above which there is little additional benefit or there may even be harm.3,4
Occasionally athletes die suddenly and these highly publicised, tragic instances generate considerable attention from the community at large, given the widely held perception that these individuals are the epitome of fitness and health. In the majority of cases, exercise acts as the trigger of the fatal arrhythmic event rather than being the primary cause. The majority of sudden cardiac deaths (SCDs) in athletes are secondary to quiescent cardiac disease that can potentially be detected during life, galvanising discussions relating to primary and secondary prevention of similar catastrophes. Primary prevention involves the identification of those at risk of sudden cardiac arrest (SCA), through population screening or targeted screening of high-risk individuals with symptoms or family history suggestive of cardiac disease. Implementation of lifestyle interventions and appropriate clinical care can prevent SCA. Secondary prevention relates to improving the probability of survival when an SCA occurs, through the implementation of an effective emergency response plan, with high-quality cardiopulmonary resuscitation (CPR) and prompt use of automated external cardiac defibrillators (AEDs) at its core.