I run daily. Not a consistent gym goer but when I go, I run in the morning and lift in the afternoon or evening. I find it much worse to run with heavy legs.
Everyone has their own preferences of course but I run outside! I live in a town that's partly in a polder so apart from the usual cycle and pedestrian routes there's a levee running through and out of the town with beautiful views of the fields, there's a small forest, some parks, etc. Sometimes it feels like the boring same-old but it beats the monotony of the treadmill, even when it's cold or rainy. It's also fun to experience the environment as it transitions through the seasons of the year.