My usual morning commute is about 90 minutes long and normally after 45 minutes or so I get a little thirsty. Never bother taking a drink with me as I am not going that far. Last night I was about to throw away another free sample of powder stuff for the water bottle, from Wiggle, but thought what the hell I will try it out the next morning. This morning, arrived at work after 41.35km feeling excellent and very feisty, wishing I could just continue riding. I seemed to have lots of speed and strength, far more than I would normally expect on a Friday. Sitting at my desk now feeling good and itching to get back on the bike already. Only downside is I feel like I need to brush my teeth again. Obviously it could all be just a coincidence, so maybe more experimentation is required. On a side note, I did ride down a very scary descent, gradient between -14 and -18%, narrow single twisty lane, high hedgerows either side but it was in a residential area so lots of driveways which where basically invisible until upon them plus traffic calming measures where traffic downhill have to give way to traffic coming up the hill. Should be an excellent climb the other way.