http://news.bbc.co.uk/1/hi/health/8307750.stm

Complete retirement 'bad for you'

Keeping active after retirement may boost health

Giving up work completely on retirement could be bad for your health, US research suggests.

The study of 12,189 people found retirees who take on temporary or part-time work have fewer major diseases, and function better day to day.

is that because they were well enough to carry on work or because they carried on working?

surely because the ones that felt young and spritely at retirement age got a job, they would have lived longer anyway

effect not cause?

edit—beat me to it!

surely people who just stop doing stuff are more liable to stiffing it. If, when you retire, your plan is to do nothing, you'll get sick quick.
if your plan is to cycling around europe shagging 21 year old european sex pots, I suspect you'll live a whole lot longer. I hope so because that's my plan.