wearing boxers over briefs protect male fertility?

Briefs are, well, constricting.

Boxers are more free with your "area".

no just keep it a loose as possible so wear nothing or boxers

People say that because the penis so near to the body when you wear briefs that al the heat kills your sperm. But when you wear boxers your penis/scrotum is free to move and get air.
Personally i think that's a lie. But briefs are somewhat more constraining on your junk.
I prefer boxer-briefs;not so tight yet gives support.

I think you misunderstood – you do NOT wear boxers on top or over the briefs. You wear boxers INSTEAD of briefs.

Dude if your equipment has no defects the type of underware you are wearing has little effect on your swimmers. If you wear butt huggers your scrotum nutsack will try and keep your nuts cool for optimum sperm manufacturing if your cold your nutsack will get high and tight against your body for warmth your body is smart and tempreture controlled it really doesnt make a difference

curtdude

It doesn't and sounds really silly. The whole purpose of underwear is to keep your outer clothing clean. That's it. 100 yrs ago, people did not bathe regularly, and may have had only one set of clothes. As you probably know, guys tend to leak urine and some don't figure out how to wipe until they are grown, so underwear helps protect the outer clothing. Briefs do not cause a reduction in sperm count, there has been no medical trials that show that– only some guys surmising that boxers are looser and therefore might keep the balls cooler. But boxer fabric is denser usually than briefs, and once the boxers are inside the pants, the balls actually get hotter than just wearing briefs. Briefs do help provide some support for the balls for active guys, so the balls if hanging don't get swung around a lot. But wearing both boxers and briefs would serve no purpose other than being really uncomfortable and hot, thereby possibly reducing fertility a bit. Considering that in the really hot places like Iraq and Saudia Arabia the guys wear full clothing and seem to be quite fertile, any ideas that tighter clothing makes you less fertile seems silly anyway.

you should be as free as possible and go with just boxers or in some cases nothing

There have been studies done to see if keeping the testicles closer to the body (briefs) will decrease sperm count compared to allowing the testicles to maintain their own distance (boxers or freeball). While some researchers claim that their results are conclusive, the scientific community at large believes that the type of underwear a guy wears does not make a difference in sperm count. So, wear what feels best to you.

It doesnt do anything to protect sperm at all, wearing more underwear would only make things warmer down there, which would actually hinder sperm production. As sperm need to be at lower than 98.6 degrees in order to fully develop.