You didn't do pushups in your karate dojo?
Stretch? It may not be specifically called "preventive training" but I've not seen a karate or TKD dojo where some part of every session was devoted to a bunch of exercises that - while called 'warm up' were also 'conditioning' - or 'prehabilitation' or....
Not that I've been to a lot of karate or TKD (one or two of each) but we sure used to do a lot of stretching, pushups and (it was a long time ago) situps in judo...
We did "stretching" (see Janet's comment), no pushups. It certainly wasn't any closer to "conditioning" than what we do in aikido (in fact I'd say the latter is somewhat better - the wrist stretches are helpful, and we do situps). It isn't conditioning. I think the idea of conditioning is great, but I don't think the dojo is the place for it (it has a different set of goals, and it takes a lot of time), and I don't see any dojo in any style doing what I'd call conditioning.