As many as one in three men say their romantic encounters end sooner than they'd expect (or want) – no wonder that at least one study found the average romp in the sack lasts from 10 to as few as three minutes. So don't become a statistic. As is the case with any other athletic activity, your sexual performance and stamina can be improved by focusing a little on your overall fitness. Scott Hays, author of 'Built for Sex' and 'Sexual Fitness for Men,' says that a few basic exercises can extend your sex sessions and make them more enjoyable as well, without requiring an elaborate workout regimen. Here are his top eight exercises.