I've had two jobs that were equally hard physically. One was brick laborer and the other was roustabout.

I wouldn't go back to roustabout. The work environment and people sucked ass. I could do brick laborer again.

Bothcan be physically exausting. Both have a high attrition rate for new hires, especially when the weather is cold or hot. I've seen guys quit in two hours on their first day. I've seen guys literally fall out. On both jobs when I first started it was only through pride that I made it. Of course it gets much easier once your muscles get broke into that particular work and you figure out the easy/smart way to do things.