Last week, I described how our busy lives - especially the hours spent in front of computer screens - were depriving us of the exercise we need to keep our bodies functioning well.
It's slowly dawned on health experts that the greatest disaster the developed world has brought on itself may well be the forced inactivity our high-tech lives demand. We're so good at improving how we work we've taken the 'manual' out of labour.
A generation ago, most people got more than enough exercise by working. Even the elite had to climb stairs now and then. Obesity was a sign of wealth, not - as it is today - a sign of poverty.
The problem is getting worse, and will take a long time to reverse. So what can we do?
Firstly, recognise that everyone needs to get at least 30 minutes - and, preferably, an hour's - exercise (moderate to intense) every day. In February last year, a Department of Health survey found that only 35 per cent of those questioned had done 10 minutes or more 'moderate physical activities during the preceding seven days'.
Secondly, find ways to get exercise into your day. Those who can control their schedules may be able to play sport or establish cardio-fitness routines. How can the rest of us make it happen? The easiest way is to walk more.