Work and sleep then - two areas that might benefit from a focus on well-being. But NEF come up with another - bicycles. Before we get into the saddle on that, let us consider one of the strongest correlations between activity and happiness - commuting.
Not exactly news to us.
http://www.bbc.co.uk/blogs/thereporters/markeaston/2011/02/happiness_work_sleep_and_bicyc.html