Experts still aren't exactly sure why they're associated, but just being sleep deprived can have a very negative effect on erections (beyond simply being too tired for sex). "We often tell older people who are having mild erectile dysfunction to have sex during the time of day when they're most rested," says Breyer. For most, that means doing the deed in the morning.
Credit: Oleksiy Maksymenko / Getty Images
Powered By ZergNet
How Liev Schreiber Fixed Himself
A Tough Guy Comes to Terms With His Troubled Past
Plus: How the Drug Cartels Took Over Mexico
ON NEWSSTANDS NOW
James Taylor's Life Advice
Sign up to receive the Men’s Journal newsletter and special offers from MJ and its marketing partners.