Why boxers get erections when they're weighing in for fights.

In case you missed it (nobody missed it) yesterday, UFC star Conor McGregor faced boxer Floyd ‘Money’ Mayweather in what was dubbed boxing’s billion dollar fight.

As was expected, Mayweather won. It’s estimated he walked away from the fight $230 million richer. McGregor scored at least $70 million… for losing. 

That is all very well and good.

But the question on everyone’s lips has nothing to do with prize money or winning or what they said to each other after the fight.

READ MORE ON MAYWEATHER: At 5am, Josie woke to find one of the world’s highest-paid athletes standing over her bed.

Oh, no. The only question following the fight of the century is: Why does McGregor keep getting erections during weigh-ins?

Look, it’s fine. His erection didn’t hurt anyone. It is our expert understanding that sometimes erections just happen. 

The two men, who were a day out from competing in one of the most anticipated fights in history, stood opposite each other in nothing more than their underwear.

McGregor started yelling in Mayweather’s face, encouraged by the cheers of the audience, and then his penis kind of just… popped up. And looked Mayweather right in the eye.

Mayweather then started pointing at and taunting the erection.

Was it an intimidation tactic? Was he roaring with testosterone? Does dehydration have something to do with it? Is he such an alpha male that he just has an erection at all times? Was it all a little too… exciting?

You see, this wasn’t the first time McGregor has attended a weigh-in accompanied by his erection. The same thing happened in 2015 prior to his match against Dave Hill.

There are a number of theories. The first, is that McGregor’s erection was an adrenal response to crisis. Adrenaline elicits the fight or flight response, and in some men, the prospect of violent conflict with another person can spur on an erection. Similarly, a primary post adrenal stress effect is a hard-on and heightened sex drive.

An erection is also a reflex that can occur when a man is, “nervous, scared, angry or under stress” and they are known to be a liability to some men in the army.

Some are suggesting that McGregor actually didn't have an erection at all, instead contending that dehydration can emphasise one's bulge. McGregor would have been seriously dehydrated given the demands of a weigh-in, and usually this would inhibit one's ability to become erect.

But Billy Coffey, a senior performance coach at PinPoint Athlete, has worked with dozens of professional athletes and isn't convinced by any of these theories.

"I think he has literally worked it so he has an erection," Coffey told Mamamia. 

"He's all about an edge. Men subconsciously measure their manliness by the size of their penis, and so McGregor has purposely done it to break down any barrier he can. Sure, testosterone will get you fired up, but not in a moment like that.

"The blood will travel to your appendages for fight or flight and to be honest, that would cause it to shrink. He is a master of mental manipulation. It's all an act.

"As for dehydration, once again that causes your body to stress. All the blood would travel to vital organs and the brain wouldn't put reproduction as a priority when it's that stressed, again supporting the idea that he works it to intimidate his opponent."

Oh, goodness.

Unfortunately, his penis did little to defeat Mayweather on Sunday.

But thanks to McGregor, we just learned far more about sportsmen and erections than we ever hoped to on an otherwise nondescript Monday.

What's your erection theory?

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