Mental fatigue is one of the most conspicuous limiting factors to professional productivity, especially now , in an era of disturbed sleep cycles, where most professionals are too tired to give their optimal output owing to fatigue arising out of “feeling sleepy”.
The phenomenon of post- lunch “dip” in alertness level refers to the sharp slump in alertness of an individual in the afternoon and early evening time period after having lunch. The consequent reduction in individual productivity has been projected to cause a large loss of revenue in the tertiary sector industry 1i.
A number of efforts have been made so far, to combat the decrease in individual alertness experienced by professionals at midday, with two schools of thought; one that propounded the use of caffeinated drink for mitigation and the other propounding the concept of “power-nap”.
However both approaches have their limitations, using caffeinated drink induces tolerance, dependence and disruptions in nocturnal sleep 2 3 while “power” napping is known to cause increased mental fatigue due to “sleep inertia” i.e. grogginess caused by disruption of an incomplete sleep cycle 4.
Hence, the concept of “caffeine nap” was proposed, wherein the subjects were asked to drink coffee immediately prior to taking a nap, such that the subject is roused from his/her nap after a time which allows the caffeine present in the coffee to act on CNS adenosine receptors; the benefits being much increased levels of subjective alertness as compared to those taking simply a caffeine drink or a simple nap 5.
While it is already established that a “caf-nap” is much more efficient way to increase alertness, its ideal duration remains to be established, especially in Indian subjects.
1. ^(ref article on web billion dollar loss) https://sleephabits.net/power-nap
2. ^and high doses in the late evening can increase the time taken to fall asleep (Smith, 2002
3. .^Neuropsychiatric effects of caffeineAnthony P. Winston, Elizabeth Hardwick, Neema JaberiAdvances in Psychiatric Treatment Oct 2005, 11 (6) 432-439; DOI: 10.1192/apt.11.6.432
4. ^Benefits of napping in healthy adults: impact of nap length, time of day, age, and experience with napping
5. ^(original british study caf nap, Reyner)
6. ^pdf.Pharmacokinetic and Pharmacodynamic Effects of Caffeine
7. ^ caffeine drug interactions???