I have a different view on your quest for an outdoor bag. If I woke up and found myself in your shoes and wanted to add heavy bag workouts to my outdoor training or add outdoor training to my heavy bag workouts what would I do? I would not wish to damage a tree (a chain or cable or even repetitive rubbing can damage and kill a tree pretty quickly) yet I would want to maximize my training time and opportunities. So what I would suggest is that you set up one or more free standing bag stands (one under cover of a tree canopy, one near water such as a lake or river and perhaps one near a view) with a easy way of hanging the bag(s). Then simply include taking your heavy bag to and from your workouts as a part of your workouts. Dragging the bag by a length of chain, lifting it and tossing it and attacking it where it falls or lean it against different trees on the way and make each tree a timed or technique circuit out of the trek to and from the workout area, or simply carrying the bag across your shoulders can all provide you with great cardio and strength and balance workouts and add endless variety to your workouts.
Good luck
Regards
Brian King
Good luck
Regards
Brian King
