I am a huge proponent of working out outside. It's great to clear the mind, get oxygen and get out of the conventional settings. Log training is a great tool to add to your workouts. There are various things you can do with log training and while I spent time in Europe I noticed this was a staple to Eastern European martial arts conditioning.
There are various exercises you can perform with long logs. Some of the exercises are below but limited: overhead squat, squats with a log on your shoulder, overhead squats, shoulder press, log flips, lunges, squats, bench pressing, balance walks, trunk rotational exercises, alternating shoulder press, rows, sit ups, throws.
If you have not already, please check out my article titled "How to build core strength with long log training"
Below are a few videos that demonstrate some of these exercises.