“A man’s body chemistry changes after orgasm. The biochemical prolactin is released, physically altering his body and making him very tired,” says Dr. David McKenzie, a sex therapist in Vancouver, Canada. 

Further, exertion during sex and after climax depletes the muscles of energy-producing glycogen, which leads to sleepiness. Since men have more muscle mass than women, they’re generally sleepier after sex.

Men’s libido goes up and down 

Think PMS is only for women? Think again. Your monthly peaks and valleys are triggered by changes in testosterone that affect your mood, libido, energy level, beard growth and sperm count.

According to research by naturopathic physician Dr. Marcus Laux, men have more energy, a greater sense of well being, lower body weight and less need for sleep during the peak of their cycle. The valleys bring apathy, indifference and the tendency to magnify small problems into big ones.

“If you keep track of your personal cycles, whether it’s shifts in energy levels, mood or sex drive, you can anticipate changes,” says Laux. “Then, you can take advantage of the times you’re at your prime and better cope when you’re not feeling your best.” 

 Disrupted sleep decreases erections 

If you’re struggling with obstructive sleep apnea (OSA), you’re at risk for sexual dysfunction. OSA is a sleep disorder that affects 18 million Americans—many of whom go undiagnosed—and causes sufferers to stop breathing dozens of times per hour.

OSA disrupts rapid-eye-movement (REM) sleep, which is when men routinely experience erections. Decreased REM sleep means fewer REM erections, which affects sexual health. “It’s possible that men need to experience REM erections in order to maintain optimal sexual functioning,” says Dr. Charles Atwood, associate director of the University of Pittsburgh Medical Center’s Sleep Medicine Center. 

“If you have erectile dysfunction, you should get tested for OSA,” he advises. “Men who are diagnosed and treated for OSA often see an improvement in sexual functioning.”  

Watch Video:

According to a new Better Sleep Council Canada survey, men and women are divided when it comes to how they’ll use the extra hour as the clocks turn back on November 2nd. Given the choice between sleep and sex, more men would choose sex and more women would choose sleep. The survey uncovered other tensions in the bedroom, with three quarters (73 per cent) saying poor sleep affects their relationship.  A couples counsellor offers tips to help couples make the most of their time in bed, whether it’s for sleep or sex. Distributed by Tubemogul.