Importantly, while those differences were significant, none of the men had clinically low sperm counts - so while wearing looser boxers might be better for your sperm count, going for tighter ones wouldn't necessarily make you infertile.
Compared to men who favour snug-fitting briefs, devotees of boxer shorts had a significantly higher count and concentration of sperm, researchers reported in the journal Human Reproduction.
They sought to test the theory that briefs, being more constricting, raise scrotal temperature and have a negative effect on fertility. The men provided information on their underwear choice and a sperm sample and blood work for analysis.
Choice of underwear seemed to affect only the total count of the sperm and the other parameters remained unaffected.
Research into the effect of underwear on sperm quality has found that men who opt for airy boxer shorts made much more sperm than those who wore restrictive pairs.
FSH is known to play an important role in male fertility.
The new findings add to a growing body of knowledge on the subject.
"We know that spermatogenesis is very, very sensitive to temperature", Chavarro said.
"As a society, traditionally, fertility has been thought of as a female issue".
Men who wear tight-fitting briefs have sperm counts that suffer in comparison to men who wear boxers, according to results from the largest study to date on the controversial topic.
Some styles of underpants, such as jockey shorts or briefs, bring the scrotum nearer to the body, causing the testicles to warm up, while others, such as boxer shorts, are looser and cooler.
Men trying to get their partners pregnant may not have to throw out all their briefs, said Dr. Harry Fisch, a clinical professor of urology and reproductive medicine at the Weill Cornell Medical College in New York City.
The men, who were between the ages of 32 and 39, completed a survey that included questions about the style of underwear they wore in the previous three months. "The testes of men wearing tighter fitting underwear would be exposed to higher temperatures than those wearing looser fitting ones".
Anything that prevents this cooling is likely to impair both sperm output and quality.
The study has still not demonstrated a clear correlation between the type of underwear and sperm count/quality and whether all these sperms translate into pregnancy.
"We were able to find a potential compensatory mechanism whereby decreased sperm production relating to the type of underwear signals to the hypothalamus to increase secretion of gonadotropin, a hormone that acts on the testes and that is reflected by the increased levels of FSH, to try to increase sperm production", said Dr Lidia Mínguez-Alarcón who led the study.
While the study is extensive, it has a few possible caveats.
India vs England, 2nd Test Day 1 at Lord's, Highlights The English summer was at its peak, the sun was beating down hard all this while but come the Test series and the clouds are out. The covers were up all the morning today and the toss was delayed and before the conditions could improve it started to drizzle.
However, a move did not materialise and Mourinho must now work with the same central defensive setup as he did last season. I had my plans for many months and I find myself with the market closed in a situation I did not think I would be in.
In May, the world-class Spanish goalkeeper won Manchester United's Player of the Year award for the fourth time in five seasons. He scored his first senior team goal with a lovely move around his defender and a fine finish to the far post.
Momager Kris Jenner reportedly offered up a sweet toast to her youngest daughter as pink confetti fell from the ceiling. Kylie shared a string of pictures of the pink styles she wore to her dual celebrations on the social media site.
Additionally, ambulances were called to Kidder's home five times in seven months, including at the time of her death. If you are struggling and need to talk to someone, you can contact Samaritans 24/7.
Munster estimates Musk will need US$25b to US$30b to buy out all the Tesla shareholders who want to sell at US$420. Musk also made mention of the "shorts", investors who bet against Tesla succeeding in order to profit themselves.
Hosts England lost Keaton Jennings for 11 runs after a quick start, as Mohammed Shami provided the breakthrough for India . Left-arm spinner Kuldeep Yadav was brought in for seamer Umesh Yadav, joining Ashwin in the slow bowling department.
The Slovenian immigrants, a former vehicle dealer and textile factory worker, had been living in the U.S.as permanent residents. Their son-in-law has frequently attacked USA immigration laws, calling them the "dumbest laws on immigration in the world".
Government officials and prosecutors would not confirm details of the Guardian report when queried by dpa. Police think the novichok was sprayed or smeared on their front doorknob with a perfume bottle.
The declaration will be in place Friday through Sunday for events in and around Charlottesville and Washington , D.C. The man accused in that attack, James Alex Fields of OH , has been charged with first-degree murder.
The United Nations has offered to support rescue and relief efforts if required. "There are only a few tourists left here". Global charity Oxfam said drinking water was scarce because of a recent spell of extremely dry weather in Lombok.
Smashdown mode forces players to choose new characters, as each elimination removes previously selected fighters from the options. For instance, if you are playing a stage from The Legend of Zelda series, then you'll be able to pick any track from that series.
MDC Alliance files court challenge to Mnangagwa's election win
Zambia risks losing aid from the USA government following the forced deportation of Zimbabwean opposition politician Tendai Biti. Mr Chamisa wants the court to declare him the victor or call a fresh election, his lawyer told Reuters news agency on Friday.
Where can you see the Perseid meteor shower?
This is the most famous of all meteor showers, and the Perseids never fail to provide an impressive display. As they burn, they create a bright burst of light across the sky - traveling at about 37 miles-per-second.
Everton fans reach on Twitter to brilliant deadline day
But, there was no dearth of suitors in his pursuit, with Manchester United and Everton showing a lot of interest in him. The Colombia global was also linked with a switch to Manchester United , but he has opted for a move to Goodison Park.
Why Trump's Turkey Tariffs Are Worrying Investors
Independent analysts argue the central bank should instead raise rates to tame inflation and support the currency. Global markets are in turmoil on Friday, with a historic plunge in the Turkish lira at the center of the chaos.