Human reproduction (Oxford, England)2026n = 1,220
CohortHuman
Researchers followed 1,220 men at a Utah fertility clinic and matched the outdoor heat and humidity each man lived through while his sperm were forming against a molecular measure of…
Translational andrology and urology2026
Narrative ReviewHuman
This review looked at whether the underwear a man wears, tight versus loose, actually affects his fertility. The testicles work best a little cooler than the rest of the body,…
American journal of men's health2026n = 485
Cross SectionalHuman
This study looked at how occupational heat exposure and fertility-related stress might affect semen quality. It compared 485 men, split into groups with normal and low semen quality based on…
Frontiers in public health2026n = 5,114
CohortHuman
This study measured how outdoor temperature tracks with semen quality, using records from 5,114 men attending a reproductive medicine centre in Wenzhou, on China's east coast. The measure it used…
Reproductive biology and endocrinology : RB&E2026n = 15,581 men (10,670 in Denmark, 4,911 in Florida)
CohortHuman
This study set out to see if sperm quality changes with the seasons in Denmark and Florida, and whether outdoor temperatures play a role. It looked at semen samples from…
Oncoscience2025n = 278
Cross SectionalHuman
This study looked at how lifestyle and hormones affect semen quality and sperm DNA health in men. It examined 278 Indian men aged 21 to 50, measuring sperm count, movement,…
Scientific reports2025n = 11
OtherHuman
This study measured what happens to scrotal temperature during a run. Eleven trained long-distance runners ran on a treadmill for 60 minutes at 60% of their maximum aerobic capacity, in…
Current opinion in urology2025
Narrative ReviewHuman
This review gathers recent evidence on what damages male fertility and how much of it can be undone. Smoking raises sperm DNA fragmentation (breaks in the genetic material inside sperm)…
Reproductive toxicology (Elmsford, N.Y.)2025n = 80
Cross SectionalHuman
This study asked which workplace exposures matter most for men's reproductive health. It took 80 men working in an automobile parts plant, measured their exposure to magnetic fields, electric fields,…
Temperature (Austin, Tex.)2025n = 31 (10 White-European, 10 Black-African, 11 South-Asian)
RCTHuman
This study looked at how the smallest blood vessels in the skin respond to a hot bath, and whether that differs by ethnicity. Thirty-one healthy young men (10 White-European, 10…
Scientific reports2024n = 80
RCTHuman
This study tested whether making training harder by adding heat, thin air, or both improves short-burst cycling power. Eighty untrained young men were split into five groups of 16: no…
Scandinavian cardiovascular journal : SCJ2024n = 2,575
CohortHuman
This study followed 2,575 Finnish men aged 42 to 61 for a median of 27.8 years and asked whether sauna habits change how dangerous high blood pressure is. Over that…
BMC sports science, medicine & rehabilitation2022n = 15
RCTHuman
This study looked at whether adding sauna sessions after exercise affects gut bacteria, intestinal barrier function, and inflammation in young men. Fifteen untrained men were split into two groups: one…
Reproductive biology and endocrinology : RB&E2018
Narrative ReviewHuman
This review pulled together what is known about how everyday life affects a man's fertility, covering age, psychological stress, nutrition, physical activity, caffeine, scrotal temperature, hot water and mobile phone…
Basic and clinical andrology2017
Narrative ReviewHuman
This is a history of forty years of French research into male contraception (hormonal, chemical and thermal) summarising clinical trials involving thousands of men and couples. Those trials established that…