2026n = 10,027 men in population studies, 51 men in clinical trial
OtherHuman
This study built a better way to read testosterone in men, especially men with obesity, by accounting for SHBG (sex hormone-binding globulin, a protein that binds testosterone and sets how…
F&S reports2021n = 40 patients enrolled, 26 completed the questionnaire
OtherHuman
This study set out to find out whether men actually use scrotal cooling devices as directed, and what happened to their semen results when they did. Forty men attending a…
Central European journal of urology2021n = 3
OtherHuman
This study tested whether a specially designed cooling garment could lower scrotal skin temperature during ordinary daily life. Three volunteer urologists wore it, with a cold pack inside that was…
Translational andrology and urology2019n = 5
OtherHuman
This study set out to find which stage of sperm production is most sensitive to mild heat. Five healthy volunteers wore a specially designed underwear that held the testicles up…
Reproductive biology2019n = 5 heated men and 27 controls
OtherHuman
This study asked what a mild, sustained rise in testicular temperature does to the chromosomes inside sperm. Five fertile volunteers wore specially designed underwear that held the testicles up against…
Experimental physiology2016n = 16 (8 per group)
OtherHuman
This study set out to see whether shorter rest periods between sets of resistance exercise boost muscle growth signals more than longer rests. Sixteen young men did leg exercises at…
Journal of assisted reproduction and genetics2015n = 19
OtherHuman
This study set out to see what sustained scrotal heating does to semen and to the sperm's genetic material in fertile men. Nineteen healthy volunteers wore a warming belt at…
PloS one2015n = 25
OtherHuman
This study looked at what sustained scrotal heating does to semen and to the sperm's genetic material in already fertile men. Twenty-five healthy volunteers wore a warming belt at 40…
International journal of environmental research and public health2015
OtherHuman
This study looked at whether spending time relaxing in a forest (forest therapy) could lower blood pressure and stress in middle-aged men with high-normal blood pressure. Men walked and did…
PloS one2012n = 14
OtherHuman
This study set out to see how cutting sleep affects glucose handling and hormones in young men. Fourteen healthy men were kept in a laboratory for two nights of 10…
Biological trace element research2011
OtherHuman
This study looked at whether magnesium supplements raise testosterone in athletes and in sedentary men, at rest and after exercising to exhaustion. Thirty healthy men aged 18 to 22 were…
International journal of andrology2008n = 25
OtherHuman
It has been suggested that cycling warms the testicles as a ride goes on, and that this in turn harms semen quality. This study tested the first half of that…
International journal of andrology2005n = 20 in cooling group, 20 in control group
OtherHuman
This study looked at whether cooling the scrotum overnight improves semen quality in men with a history of undescended testicles and a low sperm count, a group with few options…
Human reproduction (Oxford, England)2005n = 29
OtherHuman
This study set out to measure how much using a laptop on your lap raises scrotal temperature, a known risk factor for male infertility. Researchers measured scrotal temperature in 29…
Reproduction (Cambridge, England)2001
OtherHuman
This study looked at whether reducing genital heat could improve semen quality in men with a poor sperm count, poor movement and abnormal shape. It compared those men against men…
Human reproduction (Oxford, England)2000n = 9
OtherHuman
This study set out to test whether driving a car for long stretches raises scrotal temperature, a known risk factor for sperm health. Nine men had their scrotal temperature measured…
Nutrition (Burbank, Los Angeles County, Calif.)1996n = 40 (cross-sectional), 4 (deficiency), 9 (supplementation)
OtherHuman
This study looked at whether zinc levels affect testosterone in healthy men. It compared zinc levels and testosterone in 40 men aged 20 to 80, induced zinc deficiency in 4…
The Journal of urology1984n = 50
OtherHuman
This study set out to test whether cooling the scrotum could improve semen in men with a low sperm count or poor sperm movement. Fifty such men wore jockey shorts…
Lancet (London, England)1980n = 6
OtherHuman
This study looked at whether cooling the scrotum could improve semen quality in men whose infertility came with a raised testicular temperature. Six men with poor semen results and a…