Sounds to me like his detergent is not doing it's job. I would suggest switching to one with enzymes.

Hope this isn't taken the wrong way, but how is he laundering them? What kind of detergent, how much detergent, washer type, etc. Sweat smell should be out just by a simple wash, but if it's really bad, try soaking and/or using Borax in the wash. Some automatic dishwasher detergent with enzymes will give laundry a boost. Vinegar in the wash and/or rinse will also help if it's really bad.

When my clothes used to smell like kerosene and exhaust, Borax was the answer.

One other thought is the water. Could it be smelly water? Maybe needs some water softening compound?

One other thought: is there could be a smell in the machine that's transferring? Maybe run a cleaning load or two, with bleach and the hottest water on an empty load or maybe with some old rags in there would be better and see if that makes a difference. Maybe there's a mold buildup.

But first thing I'd try is Borax. That stuff is great.

Thank you for all the suggestions. I'm not sure why odor isn't being removed,but I will tell him what you both said.

Thanks again.

After searching online I found two detergents that claim to remove the odor from microfiber clothes.

I saw this one at Kroger's today: Sport-Wash

Yesterday I found this one at Dick's Sporting Goods: Win detergent

In my experience this is a unique problem with certain microfiber clothes and sweaty conditions. I have been doing laundry effectively for nearly 40 years ( I actually took mine over as an older child because I wanted to do it my way) and I have never encountered anything like the smell on my husband's company provided work shirts. They were originally laundered by a service and they have the bar code on them that made sure they were returned to the correct employee. The company decided to stop paying for that and just gave the shirts to employees to wear if they chose. His are black and I heard that this cloth, which in my mind is plastic, can be bleached so I tried it with just one, then two and I have been bleaching all of them with clorox for several months. I even soak them in bleach hot water for a couple of hours before finishing the cycle. I thought it was working but I realize his closet still stinks. its insane. I have never encountered anything like it. I don't really know if they stank when they were laundered by the service because I was never around them, they stayed at work. The tag is worn but I can read 100% polyester.