"Men who primarily wore boxer shorts had a statistically significant 25 percent higher sperm concentration, 17 percent higher total sperm count, 33 percent more swimming sperm in a single ejaculate ... than men who did not usually wear boxers", the study results say.
They sought to test the theory that briefs, being more constricting, raise scrotal temperature and have a negative effect on fertility.
"We set out to take a deep, broad look at the effect of self-reported underwear choice on sperm", he said.
"Men who wore tighter underwear had lower sperm counts than men who wore the most loose underwear", said senior researcher Dr. Jorge Chavarro, an associate professor of medicine with the Harvard T.H. Chan School of Public Health in Boston. Therefore, to determine the cause of male infertility, you first analyze the amount and concentration of sperm.
You can also avoid damage to your balls - and your sperm as a result - by avoiding high temperatures such as in hot baths and hot tubs. "We're talking in the neighborhood of about 20 million sperm difference", he said.
"It is a simple measure to wear boxer shorts when there is uncertainty regarding fertility", he commented. The study was published this week in the latest issue of the journal Human Reproduction.
To understand how underwear can affect sperm quality, the researchers collected semen samples - and preferences for boxers versus briefs - from 656 men between the ages of 32 and 39.
A study has found that men in Y-fronts produce less sperm compared with those who choose underwear that gives their testicles room to cool down. The rest wore tighter underwear.
According to experts, the reasons for this trend are mostly external: it can be both environmental factors (e.g., poor environment), and peculiarities of lifestyle (reduced physical activity, Smoking or obesity).
Oi, you, in the tight trousers.
However, the sperm shape wasn't affected and neither was the DNA quality. "That's why you see seasonal variations in sperm count", he added.
The study found underwear choice could actually be a "key regulator" of sexual development and reproduction.
So if you and your partner are trying to have a baby, boxers might be a good choice.
The conviction of the scientists reduced levels of this hormone in men who wear boxers, compared to those who have a more narrow trousers, due to the fact that spermiogenesis occurs normally and is not regulated by the high concentration of hormones, which takes effect at the time of damage of the scrotum is too narrow sheets.