Hydro splitters definitely give a fella a workout, that's for sure. It's different, though. It's weight training instead of cardio.
The way I split most of my wood, I buck it into rounds and then split it right where it is. I rarely pick up rounds of wood. I split most of my wood with a Gransfors Bruks splitting maul. The head is about 5#. I did have a love affair with the X27, but I keep coming back to the GB. I don't think I could handle a 10# maul for very long without tiring or hurting myself.
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Heh. I broke the handle in my sledge hammer. Decided I had had enough of fitting handles, went to town and bought a 10 lb Collins. Used wedge to split one block and took it back because it was too heavy, treaded for an 8lb. Couple days later I used it and discoverd that my old one WAS a 10 lb. I must just have had one of my weak moments when I tried the 10lb Collins.