[freedogger]

I was a treeplanter for eight years with a few stints of heliportable drilling, log peeling for log home builders and landscaping mixed in. All except the landscaping was paid on a piecework basis which tended to make those jobs feel more like a sport. Been writing custom software for the last twelve years.

Physical labour is great in that you never really take the job home with you. On an IT project, I will often be fully engaged on a problem or feature every waking hour until it is finished. I can relate to others that comment that the physical labour is less appealing as you get older. Working with your brain is not a given either as you age though.

The quality of people you work with has a bearing on how hard a job is. On the seismic jobs it was mostly criminals and alcoholics. This wore me out more than the physical labour did. I would choose a stressful, mission almost impossible job any time over a safe and boring experience. Going through hell and back with a group of people is a beautiful thing. You really see a person's true character. The relationships and bonds last for life. This kind of thing can happen with office work, but it is rare. Jobs that require real skill and working with passionate people are the most rewarding. Working with people who don't care, who just show up to log time, or worse, who play games and rely on politics -- these things are the most taxing and will suck the life out of you before you know it.

I haven't really answered the OP's question about which type of work is harder. I think those who have only ever experienced just one of these types of work are missing something. If you are lucky enough, try to at some point do both.