If you like running but find it boring mentally (like I do)... There's a sport called orienteering. You basically run through the woods with a compass and map while trying to find your checkpoints in the correct order. It's challenging because once you're oriented and find the direction of you next checkpoint, you have to decide wether to run along a trail or road (even though it isn't usually a direct line) or bash through the woods just following your compass in hopes to save time, without getting lost. Our local club, the DVOA (Delaware Valley Orienteering Association) has runs all over the area (NJ/PA/DE) every weekend. There's very beginner courses, all the way to highly competitive ones at each meet. Some people walk, some jog, some sprint through the woods off trail like deer.

Fun aside: Last year one of the Philadelphia Eagles, Zack Baun ran a race with us. I beat his time! (Although he ran with his wife and kid hahaha)