"Resumption of sexual activity may be part of one's self-perception as a healthy, functioning, energetic person and may lead to a healthier lifestyle generally," study author Prof Yariv Gerber, from Tel Aviv University in Israel, said.
The study analysed 495 heart attack patients from 1992 and 1993, aged 65 and under.
The experts found 47 per cent of patients had less sex or no sex at all after their heart attack, while 53 per cent continued having sex as they did before, or, in some cases, increased in frequency.
While sudden vigorous physical exertion can sometimes lead to a heart attack, the study found that regular physical activity cuts the long-term risk of heart-related incidents.
"Improved fitness and a mental ability to 'bounce back' from the shock may be an explanation," Prof Gerber said.
"On the other hand, patients who perceive their health as poor might be less likely to start having sex again."