Logging exercise on Misfit fitness tracker?

Tyke2410

I have a Misfit Flash, which I'm finding super-helpful for my weight loss, but I'm not sure how to log time spent on an elliptical trainer - it's more intense exercise than walking but not as intense as running (so I'm told).
So far, I've been logging it as walking as I thought it better to under- rather than over-estimate how many calories I'm burning, but it seems a bit mean after 40 minutes killing myself on this machine. Should I log this exercise as walking or running? Thanks!