Decided to have a go, today again: just carrying these larger, nicely round rocks while I was doing the jogging in forest. Found plenty of suitable candidates. They’re sized approximately 22 – 25cm on each side. Makes about 40-45 kg right there.
What I found surprising, is that I think this already has a good effect on my back. Doesn’t feel jaded or sore anymore. I don’t push too hard, and will keep a few days in between so as not to strain too much. In the evening there’s a soothing, calm effect from doing that sort of exercise. Definitely gonna keep doing this!