What are Watts and Mets?

The elliptical machine at my gym has an LCD readout measuring "watts" and "mets." I've always wondered what this means, and what should I be striving for?

I've always wondered what those things meant too! A watt is how much energy or power you're generating with each thrust that you make. And a met is actual the number of calories that you burn per kilogram of body weight while you're asleep (essentially 70 calories per kilogram of body weight, or a "K-CAL") So, for instance, if the LCD readout says "7 mets" then that means you're burning approximately 7 times the number of calories than you would when you're completely at rest.