Get some made of pure cotton, you should be able to wash them at 60°C from time to time. Works very well to remove smell for me. Downside is that they will stick to you during training.

Otherwise, second hand. Those can be really cheap.

Adding my two cents: It’s not just stink but stinky bacteria so laundry disinfectant in addition to regular detergent, no fabric softener (mark my words that shit is poison anyway) and you need to soak your clothes over night in a mix of water and baking soda once they start to smell. That routine will fix your problem.

Before this movement started, I bought a lot cheap under armour shirts with a mixture of 60/40 % cotton to poly.

Idk. what mixture you are going with, but up until now that percentage (and slightly off) works, really well as the cotton soaks the sweat. I’m washing it on regular temps (in a regularly cleaned washing machine and with sports detergent) and have no probs since over two years. Maybe you can find something similar.

As for EDC shirt I really just go with cotton shirts lately and use the same washing routine. I tried wood based shirts (wiljd) but they loose shape and color too early. And (pure) merino shirts are to expensive and will attract holes if you’re washing them like normal shirts. Merino mixtures might be an answer (but still expensive).

I can’t remember the last time I had a t-shirt last a year. Anyway, I was going to suggest adding Borax, but that’s a US thing I guess. Add vinegar to your wash and hang dry. That worked on my gym stuff back when I actually went to the gym a lot.

Do you buy the laundry detergent for sports?

Primark do very cheap t-shirts that last a while