Coincidently last week I bought a simple light weight sports bra as an add-on purchase to matching compression pants and leggings. The two reasons I bought the bra was for the obvious answer that I love wearing women’s clothes and the second is that I started exercising during the pandemic. I run/walk outdoors and since cold weather has arrived in the northern USA I get what is called ‘nipple chafing’. Look it up, its no joke. The bra helps prevent rubbing of the erect nipple against sweaty shirt fabric. It works wonderfully and it feels great wearing it.
Also, i recently looked up something I saw when watching a soccer (football) match where players were wear black bras under their uniforms. They are GPS bras that track many aspects of their play (amount of time on the pitch, distance run, heart rates etc). At first I thought it was for chafing too but i guess not. I guess any bit of normalcy of guys wearing bras and athletic leggings can go a long way in the big picture.