The sudden stress load placed on the cardiovascular system by sexual activity is more likely to cause a heart attack on people who have sex only occasionally, as compared to those who have sex frequently or routinely exercise. The results of a research published in the Journal of the American Medical Association on March 23 are unequivocal in stating that, “Acute cardiac events (are) significantly associated with episodic physical and sexual activity; this association (is) attenuated among persons with high levels of habitual physical activity.” Conducted at the Center for Clinical Evidence Synthesis within the Institute for Clinical Research and Health Policy Studies of Tufts Medical Center in Boston, the study provides convincing new evidence that physical and sexual activity might trigger critical and even fatal cardiac events when the body is not conditioned to handle the sudden increase in cardiovascular demand.
The detailed analysis of case-crossover studies investigating the relationship between occasional physical or sexual activity and myocardial infarction (MI) or sudden cardiac death (SCD) was conducted by calculating relative risk rates using random-effects meta-analysis and absolute event rates. The analysis was based on a statistically valid sample of US data for the incidence of MI and SCD. The researchers sought to test whether habitual physical activity levels reduced the triggering effect and to what extent.
Results showed that occasional sexual activity (among individuals who did not regularly exercise nor have frequent sex) was more likely to produce an increase in the risk of MI by a risk rate of 3.45. Occasional physical activity in individuals who did not habitually exercise produced an increase in the risk of SCD by a risk rate of 4.98. However, even just 1 hour of additional physical or sexual activity per week was estimated to reduce the risk of a heart attack to a risk rate of 2 to 3 per 10,000 person-years for MI, and to 1 per 10,000 person-years for SCD.
Among people who frequently enjoy physical or sexual activity, risk levels of MI or SCD caused by occasional physical activity were dramatically reduced to the almost negligible rate of .001. The study points out that, for every additional time per week an individual is habitually exposed to physical activity, the risk rate from sudden and infrequent sexual activity for MI decreases by approximately 45%, and the risk rate for SCD decreases by 30%.