Ok, I'm not a strength athlete (yet) but I aspire to be one lol.
I currently train weights 4 days a week, the 4 big lifts. But I also have an 'extra' day where I try and do a bit of cardio and also add on a bit of bro work. Not much though, I'm not a big fan of cardio but I know I need to do it. So I tend to do 20-30 mins of steady state cardio on the treadmill or bike, then do some bro work such as calves and bis/tris, then finish with 10mins on the battle ropes/sledgehammer swings/tyre flips. Then I'm pretty much done.
I'm not trying to become an endurance athlete or anything, or to become a fat burning machine. I'm just doing it to improve my general fitness, my occupational health nurse at work says my lung capacity should be better. I also have mild asthma, nothing serious, but it makes me short of breath of breath very quickly when doing aerobic activity, but I've usually put that down to being unfit as well.
Am I doing enough? Should I switch to HIIT for the cardio element? I struggle to fit any other days in apart from the occasional bike ride.