From rumors about feet size to sex life, there's a lot of cultural misinformation circulating about men and their physiques. And men themselves offer precious little clarification what with their tendencies toward joshing around and playing things close to the chest. So for the record, here are five classic assumptions about men's bodies that are totally false. -- Robin Nixon
Men think about sex every 7 seconds
"That is as many times as we breathe everyday," Caroll said. "Nobody has that type of mental stamina."
In one of the nation's most comprehensive surveys about sexual habits in the United states, completed by Edward Laumann and colleagues in 1994, 43 percent of men reported thinking about sex not even once a day, but rather somewhere between a couple times a week to a couple times a month.
Now See: 5 Myths About Women's Bodies
Single guys have better sex lives than married guys
Conventional wisdom says married men get nothing but slumber in their bedrooms, while single studs are "closing the deal." But it is actually those with the vows that are getting it on.
A 2006 study by the National Opinion Research Center found that husbands get lucky between 28 percent to more than 400 percent more often than bachelors, depending on their age. And it is not a ho-hum roll in the matrimonial bed; not only are married women more likely to be orgasmic, married men also give and get more oral sex.
Kind of gives a new twist to the phrase, "I do."
Semen is loaded with calories
Seminal fluid is made up of water and nutrients such as vitamin C, calcium and magnesium. It also contains the sugar fructose but only 5 to 7 calories worth per, ah, serving, according to Dr. Rachel Vreeman, also of Indiana University and Carroll's co-author.
"It is unlikely to create a diet issue, but this should not be used in an argument for whatever," Vreeman said.
If you shave your beard or head, the hair comes back faster, thicker, and coarser
"If that were true, we'd have a cure for male pattern baldness," said Dr. Aaron Carroll of Indiana University and co-author of "Don't Swallow your Gum: Myths, Half-truths and Outright Lies About Your Body and Health" (St. Martin's Griffin. 2009)
Stubble may look darker and coarser because it has not yet been exposed to sun and other wearing elements. Once it grows in, it looks identical to the hair that was shaved away, Caroll said.
Men with big feet also have big ...
It is true that the development of penises and toes (as well as clitorises and fingers) are influenced by the same gene. But the length of one does not predict the length of the other.
In a study of more than 3,000 men, no correlation was found between the self-reported size of feet and that of the crown jewels. Skeptical of a man's ability to size himself up, some researchers have, well, taken things into their own hands.
For example, a 2002 study, headed by Jyoti Shah at St. Mary's Hospital in London, compared foot size to carefully measured privates (all 104 penises were stretched to their longest length for consistency.) No correlation was found.