XBionic The Trick running shirt cools you while you go

Handy for the London Marathon on Sunday

If you're taking part in the London Marathon on Sunday, this is your secret weapon. It's a shirt that cools you down by making you hotter. Confused? Let us explain.

It's called The Trick, and it features social structures in the spine that trick the heat receptors in your back into thinking you're much hotter than you actually are. Your body then starts sweating to cool you down. The theory is that because you don't start overheating, you'll protect your energy reserves and be able to perform at a higher level for longer.

That's the theory, anyway. Without having tried it, or have it verified by an independent third-party, we can't say for sure whether it works or not.

The Trick is available now. The short-sleeved one is £79.99, while the long-sleeved costs £99.