I hit a wall where I'd come and nothing was gained by more thrusting. My problem is finding a partner who can keep up - literally! The most striking result is that there was a huge amount of variation. Gemma would love to hear from you. Why we last so long is a pretty complicated question with no clear answer, but a clue may be in the way the penis is shaped. The best study we have estimating the average time to ejaculation in the general population involved couples from around the world timing themselves having sex over a four-week period — using a stopwatch. Instead of sliding the penis in and out many hundreds of times per sexual session, why not just put it in once, ejaculate, and then go have a lemonade and get on with the rest of the day? The average time for each couple that is, averaged across all the times they had sex ranged from 33 seconds to 44 minutes. Another surprising finding was that the older the couple, the shorter the sex, contrary to the prevailing wisdom probably peddled by older men. As an evolutionary researcher, all this talk of how long sex lasts make me wonder: That is as practically awkward as it sounds: The average median, technically across all couples, though, was 5. In , researchers showed — using artificial vaginas, artificial penises, and artificial sperm corn syrup — that the ridge around the head of the penis actually scoops out pre-existing syrup from the vagina. Measuring an average time to ejaculation is not a straightforward matter.