One or more of the following reasons usually account for why a man sleeps after Sex:
• They are tired to begin with, and sex helps them relax and let go -- figuratively and literally.
• The hormones men and women produce at orgasm can lead to the desire to lay back in the afterglow, and that sense of physical peace often leads to sleep.
• The ejaculatory release for men, and the inherent letting down of bodily tension, makes men physically tired.
• Most people (again, men and women) hold their breath during sex, breathe shallowly or don't focus on breathing. I'll bet the ranch that he's not breathing deeply. That gives him oxygen deprivation, which causes sleepiness. And, it could (rare, though) persist into the next day.
phinebooty
It is a biological reaction. the release of oxcytocin has the opposite effect on men than it does on women because we are wired differently. orgasms in women make them want to go on and on but because men can only really ejaculate once their body rests after. nothing to do with holding breaths or being physcially exhausted.