Exercise can be a lonely endeavor. I am lucky to have found a friend to mountain bike with, and also our youngest son when he's around. He also got my wife and I into indoor rock climbing, which we've done together a couple times. My point is that having a "training buddy" can make all the difference. The other thing I do to stay motivated is to set goals and challenges for myself. I wrote about that here: https://robertroybritt.medium.com/why-you-need-to-climb-a-mountain-and-how-73c2e728d30a