HOW TO BEAT THE AFTERNOON SLUMP

Recent research is revealing what's causing your post-lunch lethargy, why it stalls your productivity and the best ways to get your brain back into gear

- DAVID ROBSON

It's 2pm, my eyelids are drooping and my thoughts are sluggish. I feel like I need to summon all my willpower simply to remain awake, let alone get my mind into gear for an afternoon's work. Part of me is tempted to enjoy a little siesta, but how can I justify this time away from my desk?

I haven't even eaten a large meal, just a little salad with some bread and fruit juice. Yet the post-lunch slump – known in the scientific literature as 'postprandial somnolence' – has hit me hard. It's time, undeniably, for another espresso.

Exactly what leads us to lose our energy after midday remains a matter of debate, with some research suggesting that it may be due to a natural rhythm that has very little to do with the food we eat – and respecting the brain's cadences may be far more effective than fighting them. Fortunately, this new knowledge offers some practical strategies to nudge your concentration back from its afternoon lull, as well as some tips for the perfect siesta.

THE BLUE DOT

To understand why our focus waxes and wanes throughout the day, we need to explore a tiny bundle of neurons, measuring just a few millimetres across, buried deep in the brainstem above the back of the neck.

The region is called the locus coeruleus, or 'blue dot'. It's a literal description of its appearance and a clue to its function. Cells in the locus coeruleus are the brain's primary source of a neurotransmitter called noradrenaline - the synthesis of which results in an azure pigment that gives the neurons their distinctive colour.