I signed up for Planet Fitness in my area today and did my first workout there. Been running outside since September and can pretty reliably go 2 hours at around 5 mph. But man, running on a treadmill sucks. I thought "Hey, I won't have to worry about windchill and I can watch something on my phone and it'll be easier!" Nope. Holy shit. Couldn't even go an hour without slowing to a walking pace a few times. It's so discouraging having your time and distance right there in front of you, trying not to constantly look at it. Especially with no scenery passing by or no visible progress made.
I feel like I got a better sweat out of that hour than I usually do on my runs, but I burned decidedly less calories. At least I can get into some lifting there, I suppose.
Do HIIT instead. You can workout for a lot less time and it isn't nearly as boring.