I used to improvise a technique to shake off the sleepies and also alleviate the morning boredom on the tube/subway. Just spot a word on a nearby poster or sign

I used to improvise a technique to shake off the sleepies and also alleviate the morning boredom on the tube/subway. Just spot a word on a nearby poster or sign, then look away...and spell the word to yourself backwards. The longer the better. I found it helped to rouse into an alert state, as you have to think about breaking the word into chunks. I also found it helped focusing the "minds eye" to visualise segments that could be picked off in reverse. After fiddling with it for a while, it's the same drill for "drill" and "antidisestablishmentarianism" :-)