Harness training opens up a safer middle ground between full-outdoor and never-outside. Not every cat takes to it, but the ones who do gain real enrichment.
Start indoors
Let your cat wear the harness for short sessions indoors, with treats, before clipping the leash on. Walk inside for a few days before the back yard.
Build slowly
First outings should be quiet, brief, and in a safe spot — a back yard, not a busy street. Watch for signs of stress: low body, dilated pupils, tail tucked.
If your cat sits still and refuses to move, that's not stubbornness — that's overwhelm. End the session calmly and try a shorter one tomorrow.