For the past four years, Helen Fisher, an anthropologist and author of Anatomy of Love, has been crunching the numbers from a massive sex survey undertaken by the Match.com dating site. (It sampled 20,000 unmarried American men and did not include Match.com clients.) "I was horrified," Fisher says. She found that for men in their sexual prime, or twenties through forties, 20 percent hadn't had sex in the past year and 25 percent reported it happened once a month or less. "It's really a sexual famine for single people in this country."
Mind you, we don't know for sure that men are getting it on with startling infrequency compared with a generation ago. Anthropologists weren't consulting for dating websites 30 years back. But modern life – the brutally competitive job market, the ever-plugged-in digital culture, the ready access to sex-drive-depleting medications (SSRI antidepressants, blood pressure meds) – suggests it. "These guys are coming out of the woodwork," says endocrinologist Florence Comite, a New York City antiaging doctor. "They're feeling overwhelmed, they're juggling a million things, and their libido is down."
Even psychologists agree that the remedy may be to focus on the body before the brain. "The solution to low sex desire has to do with lifestyle change more than some blinding insight about how sex really represents some subconscious thing that you didn't know it represented," says Russell Stambaugh, a clinical psychologist in Ann Arbor, Michigan, and a spokesperson for the American Association of Sexuality Educators, Counselors, and Therapists. Focus on key physiological factors and your mind follows. The bigger takeaway: Loss of sex drive isn't the inevitable baggage of aging – your sex-life success is in your own hands. So to speak.
Get More Sleep
In 2012, University of Chicago endocrinologist Eve Van Cauter subjected a group of healthy, lean men to sleep deprivation in a lab – the guys logged five hours a night – and monitored their testosterone levels. She expected some drop in the sex hormone – earlier work had established that men with sleep apnea are more likely to have "low T" – but was shocked to discover that after a week, these fit dudes had an average 15 percent drop in testosterone. Consider that science's standard T decline is a 1 percent drop per year for men in their late thirties and, Van Cauter says, "we're able to say that sleeping five hours a night, which many people regularly do, corresponds to 15 years of aging in one week." Hormonally speaking, of course. She adds that while a lot of middle-aged men talk to their doctors about testosterone gels to enhance libido and boost energy, "it's possible that an extra hour in bed might do the trick."
Let's be clear. The testosterone number on your lab report isn't the be-all for libido. But to the best of our knowledge, testosterone is the primary biochemical driver of desire. Keep those levels as close to your youthful high-water mark as possible, and you defend your drive against the predations of time, especially if you're one of the 25 percent of men with low T readings, in the 200 to 400 range.
Van Cauter explains that one reason testosterone is so tethered to the amount of sleep you get is because that's when the body produces some 80 percent of its androgens (male hormones and human growth hormones). And most of that production occurs during the first and deepest phase, "slow-wave" sleep. Sadly, this rejuvenating interlude does shrink with age. A guy in his mid-twenties may get 80 to 100 minutes of slow-wave sleep, Van Cauter says. By age 40 that number can be cut in half or more.
The remedy for that is straightforward: exercise. The man who regularly sweats can stave off half of his slow-wave sleep decline, Van Cauter estimates, keeping T levels high. This past spring, Swiss researchers refined the exercise prescription. They found that regular, vigorous exercise increased hormone-enhancing slow-wave sleep by up to 15 percent more than moderate-intensity routines. According to study coauthor Serge Brand, evening workouts, within a couple hours of bed, delivered the biggest bang for the buck.
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