Sudden Cardiac Death Risk and Exercise.

Sudden cardiac death (SCD) accounts for 50% of all deaths from coronary heart disease, and is defined as death with cardiac origin within 24 hours after onset of symptoms. A 19-year study looked at the impact of high leisure-time physical activity (LTPA) combined with cardiorespiratory fitness (CRF) on the risk of SCD. The results showed that the risk of SDC was nearly double among men who are inactive (low CRF and low LTPA).
Kuopio Ischemic Heart Disease Risk Factor Study, September 2013