Do you want to see my forest training? Well, in the forest you can use only heavy wood logs...I can train my biceps with heavy logs...making my biceps grow day by day to 43cm!!! Logs are more heavy and hard to control than weights as there is no smooth holding position...so you need to be super strong to lift them up. As part of my training I lift them overhead, one hand curls and much more...you must see this powerful video.