7 Surprising Things that Can Affect Your Sex Life

Photo: ThinkstockBy Jenna Pincott

His Belt Size

Over the years, his waistline has stealthily expanded (whose hasn't?), but you've never let it get between you and a great sex life. The surprise: His extra weight may actually have tipped the balance in your favor. Fat men last longer--so finds a study published in The International Journal of Impotence Research showing that men with a higher body mass could make love for more than seven minutes on average, versus less than two for their fitter and slimmer peers. Body fat may protect against premature ejaculation because it contains high levels of the sex hormone estradiol, which slows down a man's ability to ejaculate. (Note: There's a sweet spot--levels that are too high may lead to erectile dysfunction, a condition more common in obese men.)

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The Wrong Pocket Rocket

Your super-charged, jelly-rubber rabbit may be turning you off--you just don't know it yet. Some sex toys (seven out of eight in a study by the Netherlands Organization for Applied Scientific Research) contain dangerously high concentrations of phthalates, which are new-car-smelling industrial chemicals that make plastic soft, squishy and easily molded into bumps, ridges and pearls. Problem is, phthalate exposure--and the genital tract is especially vulnerable--is associated with serious health problems, including lower testosterone levels (which may affect sex drive), lower sperm counts and even certain cancers. The jury is out on the chemicals' exact toll on life and libido, but better vibes come from safer materials: medical-grade silicone, glass, metal and wood (or rolling a condom over a trusty old fave that you suspect has phthalates).

A Drafty Bedroom Window

Men aren't the only ones whose extremities need warming up. Women's do, too--down there, way down there. In an orgasm study at the University of Groningen, half the couples were unable to make it to climax. The problem was cold feet, literally. Once socks were offered, the success rate shot up to 80 percent. Comfort is key--and the area of the brain associated with genital sensation is right next-door to the one associated with feeling in the feet, writes Daniel Amen, MD, in his book Unleash the Power of the Female Brain.

A Drafty Bedroom Window

Men aren't the only ones whose extremities need warming up. Women's do, too--down there, way down there. In an orgasm study at the University of Groningen, half the couples were unable to make it to climax. The problem was cold feet, literally. Once socks were offered, the success rate shot up to 80 percent. Comfort is key--and the area of the brain associated with genital sensation is right next-door to the one associated with feeling in the feet, writes Daniel Amen, MD, in his book Unleash the Power of the Female Brain.

City Streets in Summer

More specifically, any foul odor--a public restroom, old squeegees, fish bits or any other nose-wrinkler--primes the subconscious to send you a message: "Protect yourself!" The result of
spending time in a stinky space is that we unthinkingly have safer sex, finds a study at the University of New Mexico. Men and women sitting in a room that smelled (they were told a sewage pipe broke) reported significantly greater intentions to use condoms than those in a normal-smelling room. An innate disease-avoidance mechanism kicks in--which (if an off odor doesn't turn us off completely) could lead to fewer STIs and unplanned pregnancies.

Baby-of-the-Family Status

How many lovers do you hope for in your lifetime? How many for your partner? Your answers (partly) depend on your birth order, finds a study at Florida Atlantic University. Firstborns desire fewer sex partners on average (four) than their younger siblings (13). In general, firstborns focus on long-term goals like having kids earlier in life, while the younger sibs more often pursue short-term sexual strategies. The explanation: The eldest identifies more with parents and the status-quo norms; the others don't have the same expectations and limitations. (In case you're worried: While later-borns may desire more lovers overall, there's no evidence that they're likelier to cheat.)

Low-Riding Handlebars

We've long known that long-distance bike riding is bad for a man's sex life (heat, pressure, friction = lower sperm count and erectile dysfunction). But women who ride a racing-style bike with handlebars lower than the saddle for more than 10 miles weekly have a serious problem, too--a sustained loss of feeling in their genitals--finds a study at Texas A&M Health Science Center. That sleek, forward-leaning position puts undue pressure on the soft tissues of the perineum and pelvic floor. Riding this way, you may be the hottest, fastest thing on the road but slower to warm up in bed. Better for your sex life: the upright 50's-style ride lovingly known as the "Granny."

The Three-Cent Thing He Never Uses

When a man doesn't floss, bad breath isn't the only problem that can affect his sex life, finds a study published in the Journal of Sexual Medicine. Those with gum disease--an all-too-common result of dental neglect--are more than three times likelier to have erectile dysfunction than those with healthier mouths. Unflossed gums harbor bacteria that can enter the bloodstream. This clogs blood vessels, which in turn reduces the blood supply to that crucial organ (oh, and the heart, too). Flossing: It stimulates more than gums.

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