The amount of energy expended during intercourse varies on a number of factors. An older male practicing male-on-top intercourse expends around 3 METs, but some men may expend up to 6 METs.
In general a male who can exercise at a level of 5 or 6 METs without symptoms should be able to have intercourse safely. Cycling on level ground at 10 miles per hour involves 6 to 7 METs while walking on level ground at 3 miles per hour involves 3 METs.
For a patient with severe coronary artery disease then exercise stress testing may be warranted. If the patient is able to tolerate 7 METs or more without symptoms or ECG changes then the risk of an acute myocardial infarction associated with intercourse is very low.
Ways to reduce the risk:
(1) Exercise regularly, preferably at 6 METs several times per week (Tofler and Muller).
(2) Stop smoking if still doing so.
(3) Avoid cocaine or other stimulants.
(4) Take antiplatelet medications as directed.
(5) Use alternative sexual positions with less physical exertion.
If the risk of acute myocardial ischemia is deemed acceptable by the patient, then use of sildenafil or other medication for erectile dysfunction is appropriate provided there are no contraindications.
