Why is it harder going downhill?

I'm spending a few days in the gold and green Shropshire Hills. Small flocks of redwings and fieldfares are working across the trees. I have to say there doesn't seem to be an abundance of haws - little wonder the mistle thrush are being vocal. Although the holly trees seem to have done better. I regularly see buzzards flying over the caravan but have yet to spot a red kite. I'm told there was a pair around here although it's possible they've moved on. I'll keep looking.

This afternoon we enjoyed a short, energetic walk up the double summits of Earl's Hill. The colourful oak, ash, hazel and beech soon gave way to pines as we began the steep climb. And just as the path levels, I climbed over a stile to be greeted with the final gasp - another short but steep grassy climb - but well worth the effort for the views from the top. And then the difficult bit: skidding back downhill. It must be something to do with how our feet grip the ground, or maybe the way we place our feet, but whatever it is, it's always easier to climb than come back down (or is it just my mentality?)