How Sleep Duration Affects Sperm Quality

It is well known that lifestyle factors such as smoking, poor diet and recreational drug use affect sperm quality. What isn't widely known is how sleep habits can affect sperm health. However, this study set out to determine exactly how the duration of sleep and the quality of sleep affects sperm health. 1487 men aged between 22 and 45 years were recruited for the study. An initial sperm assessment was performed to check eligibility for the study. The participants were required to have normal sperm health prior to the study and meet the following criteria:

• Sperm count of more than 60 million per ml
• Progressive motility higher than 60%
• Normal morphology higher than 30%

Interestingly, these are the numbers I aim for when treating a couple for infertility but they are certainly not what the labs consider "normal" these days. The study found that men who slept between 7.5 to 8 hours at night had no change in sperm quality. However, men that slept for less than 7.5 hours or more than 8 hours had lower progressive sperm motility (how fast it swims and if it's swimming in the right direction). Napping during the day and poor sleep quality was also associated with a decline in sperm health. Ref: https://doi.org/10.1016/j.envint.2019.105368