I've been working through a couple cords of rounds processing them for 17-18, 18-19. I travel a lot so when I get an hour or so at home I get on it. Yesterday I had a couple of Black Cherry rounds with knots. So I gave it some hard whacks! Then.....crud felt my abdominal muscle on the left side start hurting! Tried a couple more, yep, now I have to take some time off. Guess this is what "60" brings!