Researchers also found that men who wore boxers had 14 percent lower levels of follicle-stimulating hormone (FSH).
Studies on the impact of underwear styles on sperm production have been inconsistent, though research has shown elevated scrotal temperatures can adversely affect testicular function, the Chan School said in a statement.
Men who primarily wore boxer shorts had a 25 per cent higher sperm concentration, a 17 per cent higher total sperm count and 33 per cent more swimming sperm in a single ejaculation than people with tighter trousers, the study found. Could modern living really be threatening the survival of our species? "I think we still have a lot to learn about men's contribution to fertility".
Both men who wore boxers and men who wore tighter underwear had average sperm concentrations that were "normal"; that is, they had at least 15 million sperm per milliliter of semen.More news: #2018ZimElections: Chamisa files court challenge to election result
That is not the only benefit for people who wear boxers or any loose-fitting underwear, these men also have a higher percentage of what is known as motile sperm.
Men who wear tight underwear could increase their chances of having children by switching to looser fitting boxer shorts, scientists are recommending.
The authors concluded that certain styles of male underwear may impair spermatogenesis, which may result in a compensatory increase in gonadotrophin secretion, as reflected by a higher serum FSH concentration in men who frequently wore tight underwear. To understand this, the researchers first collected semen samples from 656 men between the ages of 32 and 39 and asked them what they preferred more, boxers or briefs.
A new USA study has found that men who wear loose-fitting boxers have a significantly higher sperm count than those who wear other types of underwear.More news: Annual meteor shower to peak this weekend
In the end, the researchers tested the sperm quality by counting the total number of sperm in the samples and their concentration in the seminal fluid and the concentration of the enzymes responsible for sparsogenes.
The study was published on Wednesday in the journal Human Reproduction.
Researchers, however, also say that the findings of the studies can not be generalised as the study focuses only on men attending the fertility centre. If your testicles feel hot and squashed, it might be time to swap to boxers or get some jeans in a larger size. When men have trouble conceiving, "we hope that there are other ways that we can intervene that have a little more significant science and data to back them up", she said.
However, they said that there could be further factors that weren't included in the study.More news: In Australia were allowed to kill kangaroos
The type of underwear the men wore was self-reported and not verified by researchers.