Just been out on my mountain bike for an hour. What a feeling flying down a rough track at 20 odd mph hanging on for grim death. Quickly getting splattered from head to toe in glorious mud, eyes streaming, thighs wobbling a bit (from the initial climb to the top of the hill) and all cares and worries totally banished from my mind. I love that feeling of the wind rushing through my hair (I have some, honest) and getting back home nice and tired - but glowing! So come on, what gives you a buzz?