Late-night antics in the fight of the fittest

Getting fit and losing weight has never been so much fun - and so deadly serious

As I write this, I am preparing to commit the foulest of deeds, one I have plotted for nearly two days. It's approaching the bewitching hour, and a few kilometers away my fiercest rival is, I hope, about to fall into the arms of Morpheus. When he awakes, the deed will have been done. It's the last day of February in a leap year, and I am about to get the most out of the extra time to make a leap he will never forget.

The thing that brings us two together - and pits us against one another - is our membership of a group that does physical exercises and keeps a monthly ranking of who is doing best on a smart phone app.