On Friday morning I had the distinct displeasure to realise I was going to be useless during the pre-lunch two and half hours double-session course scheduled for that morning. ( Because mornings. Enough said. )
Which would bring us to today, and the mediocre cup of coffee I had in the morning, followed by one good cup at around lunch time. With the exception of a few sips of Coke Zero throughout the day, I've managed to survive a tiring day with limited artificial stimulation.
I'm not done tweaking my caffeine levels and recording what happens, but I do have to say today was physically exhausting, yet it took longer than expected to feel mentally tired. My focus could be benefiting from this new arrangement, though it's too early to say if this can be sustained, or even whether other factors might not have been hugely influential.