Some of my synthetic fitness/cycling clothes will retain B.O. even after washing in regular detergent. I began using a product called "Win" and it was fabulous! It went out of production for a while but they're making it again but I know of no stores in my area that carry it. You can buy it directly from them for $20 for a two-pack of 21 oz. bottles plus $8 shipping ... too much. Amazon has it for the same price but you can get it shipped free if you have enough other stuff you're buying.
While Win was out of production, I started using Penguin Sport Wash. About $10 for 20 oz. at REI. It does works well, I have to say.
With either of those products, you get maybe 15 loads out of a bottle. That's almost 70 cents per load. For a couple of dollars more you can buy a 100 oz. bottle of Tide that will give you 64 loads ... a little less than 20 cents per load. But it doesn't get the stink out. I even tried the Tide sport wash with Febreeze but it left my clothes with such a heavy perfume smell I couldn't stand wearing them.
I'm washing at least one load every week and am wondering if there's something else out there that gets rid of the B.O. but without costing so much.
What works for YOU?