Summer, late spring and early fall are easy, we go on lots of walks and play outside. Winter months in the Midwest is another story. Max hates rain and snow, he will give me the look saying "don't make me go out there". We try to play in doors and to keep his mind active we will play some find it or do some training. Have been thinking about agility training for Max, I think he would be great at it!
While physical exercise of some sort is important too, mental exercise in training will tire them out even more than physical exercise. "games" and play are fun, but these dogs LOVE training, and there are SO MANY fun things you can teach them, even in a small space.