Who will you back in the Paris Marathon? Springy, sustainable son Luke (fast, system 1) or frail, fossil-fuelled father Ian (slow, system 2)? You can back us both here - and help us support the Rainforest Trust.

It's our first marathon together and we've even done some training (not enough, by a long chalk). We've had a lot of kind people asking if they can sponsor us for a good cause - so we chose Rainforest Trust because  of a shared love of the outdoors and wish to do something positive for the planet. 

Rainforest Trust has already placed over 40 million acres under permanent protection. That's worth running for, and maybe worth a small donation? Thank you ...