Why Can't I Sideload Apps to my LG G Watch?

I'm having trouble sideloading apps to my G Watch. I run ADB, connect everything, start debugging, and it says it is connected. Then, when I type the "adb -e install APPNAME.apk" it immediately tells me "Invalid APK file: APPNAME.apk" even though the apk is in the adb folder. I've tried multiple apps so far and none of them will work. Any ideas?