Results of the National Social Life, Health and Aging Project research conducted by the National Opinion Research Center at the University of Chicago showed that some 84 percent of men and 62 percent of women between 57 and 64 reported having sex in the past year,
For people between 75 to 85, 38 percent of men and 17 percent of women surveyed told they had sex during the same period.
The survey conducted from 2005 to 2006 covered 3,000 respondents who were asked about their sexual relationships the last five years.
The findings were published in The Journals of Gerontology.
The respondents defined sex as foreplay and vaginal intercourse, though they also reported engaging in oral sex.
More men aged 57 to 64 or about 62 percent reported having oral sex the previous year while 53 percent of women of the same age group tried it.