I try to keep the cadence high, so drop down the gears accordingly. Seems to work for me anyway. Too high a gear and I burn out very quickly.cheers its not so much the energy bit its more of the speed at which I climb when I got to the climb on Thursday I was fine the climb destroys me it down to fitness I think. looking at our watt to kg we pretty close on the flat I think we similar weight but u destroy on the climb same on the last mountain coat