I am teaching English at primary and junior high schools in Japan and would like show some simple but fun sports, hobby and gym based animations with clean backgrounds for my self introduction session. I'll act out some myself (maybe double up) and I know there are free stick figure making and animation software but I don't trust my ability to draw a good one. The range of activities sought is primarily gym-based including "Body Pump"- weight-lifting to music- group fitness, weights machines, free weights, running on track, swimming, sauna using, bathing plus other hobbies/ sports demonstrations- not particular about which ones. I am going ask them which one of these two do I do at the gym. So is there a website where I can find all the animations sought? Google is so useless- only found a a few and many not useful ones and no websites with helpful search functions or internal categories.

The point of the lesson is not to learn that vocabulary but to familiarise them and engage them with me as their new Assistant Language Teacher with general English exposure- I am hoping they have a fair understanding of gym activities in general even though they would probably never have been to one- limited access for children they might do .
I'm not certain I understand what you want, but have you tried youtube? I found gym exercise animations easily.

Thanks for your reply. One- I am probably past doing any more self-introductions. Two- most classes don't have any Audio Visual equipment (one classroom (4 classes) only set up theirs after my self-intro class) so I'd have to do screen capture and isolate an image and then print.