are there days where you only train certain parts of your body / only do certain exercises because you simply don’t have the time for a full workout?
my ideal workout means stair climbing, running-walking and stretching. It can well last 2 hours.
Some days I don’t have enough time to do all that. Would it be better to do less of each kind of exercising or just to fixate on one kind?
You’re aware of low-volume HIIT? Max 15 minutes per day, evidence-based for cardiovascular health same as “normal” exercise. Not for building muscle afaik, and finding your own among the many more-or-less tested ones can be a chore. The popular “Scientific 7-minute workout” and it new versions would probably be a good place to start, and are targeted more for building strength afaik.
https://pubmed.ncbi.nlm.nih.gov/37939367/ https://archive.nytimes.com/well.blogs.nytimes.com/2013/05/09/the-scientific-7-minute-workout/
Edit: Oh, and to answer your question, I don’t. I do move about by bike and play BeatSaber because it’s fun, otherwise decomposing.