As someone who runs a lot with a pack that typically weighs forty pounds, I highly recommend that you not do this. FWIW, I don't believe I'm damaging my joints

As someone who runs a lot with a pack that typically weighs forty pounds, I highly recommend that you not do this. FWIW, I don't believe I'm damaging my joints by what I do, but I spent many years hiking with a pack and then many years running without a pack before I started running with a pack. It can, however, be done: https://github.com/ctm/Bataan-Memorial-Death-March https://github.com/ctm/Bataan-Memorial-Death-March