The Internet-based survey, conducted by medical-based advertising agency Dentsu, Sudler & Hennessey Inc., found that many respondents claimed stress from work, and a lack of fulfillment in their daily lives led to their sexlessness. The poll also highlighted a lack of energy among young people.

A total of 16 percent of men in their 20s were sexless, compared with 38 percent of men in their 40s, the survey found. "Sexless" is defined as having no sex or sex less than once a month.

When the respondents were asked if they had an erection when they woke up in the morning, one-quarter of men in their 20s said they never had one or had one less than once in five days, while 28 percent said they had one every three or four days.

Altogether, 10 percent of respondents thought they suffered erectile dysfunction to a level that prevented them from having satisfying sex. When asked "When did this start?" the average answer was at the age of 32.

A total of 29 percent of people in their 20s said they had "hardly any or only an occasional" interest in sex. The figure for those in their 40s was 35 percent.

When asked about their daily lives, 20 percent said they experienced an extreme amount of stress, while 65 percent said they experienced some stress. The top reasons for this stress, with multiple answers permitted, were "work or superiors" (86 percent), followed by "household and family" matters (26 percent).

Some 84 percent felt "kind of tired," while a total of 83 percent felt "irritated," 43 said they felt "like crying," and 27 percent said "I think it would be easier for other people if I died" as a feeling they sometimes, often or always had.

A total of 29 percent said they hardly ever felt good when they woke up in the morning, 23 percent hardly ever felt hope for the future, and 12 percent hardly ever felt they were a useful person.

The random sampling survey was conducted over the Internet on Sept. 23 and 24, on 500 men aged in their 20s to 40s and living in the metropolitan area.