In January 2020 researchers from Turkey published the results of their study to assess the association between lifestyle factors (body mass index, smoking, alcohol consumption, coffee intake, physical activity, sauna and cell phone usage, wearing tight-fitting underwear), and semen quality. A total of 1,311 males were included in the study, 852 with normal sperm and 459 with sperm of reduced quality. Information on modifiable lifestyle factors was collected via questionnaire. Results showed that those who wore tight underwear had reduced sperm count and lower motility. It was also seen that going to a sauna regularly also reduced sperm count.
Kaya C et al. The effect of modifiable lifestyle factors on semen quality. Rev Int Androl. 2020 Jan 14. [Epub ahead of print]