Could the student be referring to trading speed for height, i.e. using those few seconds whilst losing speed between cruise and glide speed (approx. 20 - 30 kias) to pick up 100 - 200+' in a straight climb whilst using the time to switch on the fuel pump, change tanks, apply carb heat and commence trimming for the glide (which then starts at a greater height AGL)?
Just a thought.