Miranda Thompson writes: GoodGym got hot and steamy on Monday night as a group of 18 runners headed to Spitalfields City Farm to (quite literally) muck in with a bit of farming. The mission? Swap trainers for wellies and get stuck into a steaming muck heap, transporting the brown stuff from one end of the farm to the other to add to its compost pile. In a sauna-like atmosphere of gently fermenting pig poo, GoodGym runners got down and dirty with picks and shovels, creating a conveyor belt-style system where the compost was ferried from the muck heap to the compost beds at the other side of the farm, with a soundtrack provided by neighbouring donkeys. There, waiting runners showed us their very best star jumps as they jumped the piles into submission.It was an upper body workout to rival any weights class - and with the amount of heat we uncovered, potentially a new rival for Bikram yoga? 45 minutes later, still puffing its eggy fumes, the muck heap had almost halved in size, whilst the compost heap was considerably boosted. Job very well done! One group opted for a 3.6km tour back to the Arch Gallery past the canal while the others puffed through some serious sprints through Bethnal Green, where, despite being denied entry to the park (darn you, winter closing hours), they finished with some punishing 20 second bursts.