When I check more than one thing in the training type filters I almost always want videos that fulfill both options and not one of the two. Like if I check low impact and cardio... I want low impact cardio videos - ones with both tags, not one or the other. There's no real way to narrow down the video selections, you just kind of have to sift through all of them in one of the categories that gets close.
A "not" filter section would also do the job, ie I could say cardio but not hiit (that's another separate annoyance - hiit is already a filter, it doesn't need to be included in cardio too, sometimes I want just regular cardio without sifting through all the hiit videos as well).