I was out riding some single track the other day and the thing that struck me was the concentration involved. I found that about an hour in of no-stop mostly very twisty and mostly flat riding I was just beat mentally. There is just no time to let the mind wander at all.

Next time out I made sure to take a break every 20 or so for a slug of water and a bit of enjoying the surroundings. Much better.

... I am also coming around to the suspension idea. I ride a vintage MTB with no suspension and I am begining to think of tree roots as evil.