I use to mountain bike in the woods on a trail by my house about 20 plus years ago. It was a trail used by a small farm that had horses. I never saw another person there except for the occasional horse back rider. It wasn't a challenging ride and relatively safe. The strangest thing I saw there was a car from the 1920's completely surrounded by trees. I wonder if they drove it into the woods and it got stuck with no way to remove it. It had many bullet holes in it. I assume from hunters using it for target practice. I would ride in the winter in the snow too with knobby tires. When the mountain bike explosion happened by me my trail was discovered and then mobbed with all these knuckle heads on bikes. Wonder if it was put on the internet?
Since I had so many great rides there I wanted to try somewhere else. I went to a place popular with mountain bikers. I nearly broke my neck it was so dangerous. Steep declines with sharp turns between trees with roots sticking out. I am for the workout and not for the "thrills". I never rode there again and I refused to do any technical riding.
One take away was that biking didn't interfere with my weight leg workouts. If I run too much I'm definitely weaker for leg day.