Cardio + Strength = ?

Anyone here who does both cardio and strength training on the same day and still able to make progress?'

Or is it as I suspect that they should be kept on different days altogether?

I've just started swimming and doing f1/h1. No noticeable hindering on progress yet.

I run in the mornings and F1/H1 in the evenings, every M/W/F and am making slow'n'steady progress.  It works for me, because I need the physical and mental rest days on Tues/Thurs