This seems more like it would be in the HIIT category, in that it's primarily aerobic. (Which isn't to say that it won't increase your strength.)
I don't know that there's any definitive answer to "what is heavy lifting". Heck, for a little old lady, a soup can probably seems like heavy lifting!
For me, if I can do a particular lift more than 10 times, then I don't consider it lifting heavy.