Are you able to have a strong erection and go for a while during intercourse before ejaculating? That possibly points to good health – the keyword being "possibly".
The more you ejaculate, the more you potentially reduce the chances of prostate cancer we know, according to widely cited Harvard University research, which is why frequent sex and masturbation is advisable for men.
But the truth is that's only part of the puzzle when it comes to men's reproductive health issues. Prostate cancer, specifically, is still an area shrouded in mystery that scientists can't quite demystify – and men's general reluctance to get frequent medical examinations is only making things worse.