Years ago after complaining to my doctor i got a formal Sleep Study done (expensive and very uncomfortable to do). After several more tries of the same Sleep Study over several years i finally got a formal Diagnosis of Sleep Apnea in 2017. I was prescribed a CPAP machine to use while sleeping. It provides air pressure into my air pathway at night to ensure i breathe properly.
Breathing properly at night means better sleep. Better sleep means you wake feeling rested, refreshes, energized, and have sex drive.
As my therapy progressed with the machine, my doctor increased my pressure a lot gradually over a year. While i am still trying to get my nightly apneas lower, i can no longer go without my CPAP ever. When i go without, i feel terrible (way more fatigued, sleepy, headaches, irritable, etc).
I believe strongly that good sleep is crucial to sex drive, recovery time from ejaculation, and feeling good and healthy and energized overall
I am not sure what exactly the connection between sleep or sleep apnea and POIS might be, but i highly encourage everyone to ask your doctor about getting a Sleep Study done to test for Sleep Apnea