>> First, if you are doing heavy work, like fixing roads, you usually can't do it all day Not sure if this is true. I worked at a building site labourer and I'

>> First, if you are doing heavy work, like fixing roads, you usually can't do it all day Not sure if this is true. I worked at a building site labourer and I've seen people digging trenches all day. I'm also pretty sure in the poorer parts of the 3rd world people are toiling for 8 hours a day in manual/ox-assisted agricultural work.