One for Rig I think. At a typical Parkrun - at least ours - the first runner takes 17 minutes or so to complete the course, while the tail runners (neglecting walkers and similar) take around 40 minutes. Both feel that they have put a lot of energy into their run, though those in the lead are working at a greater rate and the slow runners are working less hard but for much longer. How do their calorie counts compare? (and the figures at all reliable?).