Who would have thought that the better way to increase productivity is to allow employees to take a quick post-prandial nap at the workplace? A paper published recently by the non-profit National Bureau of Economic Research (NBER), based in Cambridge, Massachusetts, U.S., argues that higher quality sleep during a power nap improves economic and psychological outcomes over an increase in the number of hours of sleep.
The paper, by Pedro Bessone et al, was based on a project that measured sleep among 452 low income adults in Chennai, and acknowledges “generous funding and support” from the government of Tamil Nadu and the Massachusetts Institute of Technology-based Abdul Latif Jameel Poverty Action Lab, among others. “Adults in Chennai have strikingly low quantity and quality of sleep relative to typical guidelines: despite spending eight hours in bed, they achieve only 5.6 hours per night of sleep, with 32 awakenings per night,” the paper states.
‘Sleep efficiency’
“Sleep efficiency is calculated by dividing the sleep you are getting by the time spent in bed, expressed as a percentage,” explains Dr. N. Ramakrishnan, senior consultant, sleep management, Apollo Hospitals, here. Just over five hours out of eight hours in bed is not good sleep efficiency, he adds. That means sleep efficiency was only 70% in the sample, which, the authors argue, was “much lower than in U.S. populations or even those with disorders such as sleep apnea”.
As part of the study, the subjects were recruited for a full-time data-entry job for one month. The researchers then cross-randomised the sample into two types of interventions to increase sleep: night sleep treatments, and a nap treatment that gave them, daily, an opportunity to take a half-hour nap in the afternoon in a quiet space in the office.
Qualitatively better
The night-sleep interventions increased sleep by an average of 27 minutes per night, but this increase in time asleep was entirely driven by greater time spent in bed — on average 38 additional minutes per night — rather than improved sleep efficiency. Naps were effective at increasing sleep — 88% of individuals fell asleep at some point during their allotted nap time, yielding an average of 13 minutes of nap sleep per day. This was of a higher quality than night sleep, the NBER records.
Increased night sleep did not have any measurable positive impacts on a range of outcomes. Naps, on the other hand, increased work productivity by 2.3%, boosted a measure of attention, and improved psychological well-being. It also emerged that naps increased patience, and actually resulted in 14% higher deposits in a savings account, according to the paper.
Environments contribute
“There is no doubt that both quality of sleep and the hours you get are important. But, lying in bed is not equal to sleep,” Dr. Ramakrishnan explains. “In this particular study, the environments might have contributed a great deal to the benefits derived from the nap.” In a low income group, he argues, the environments in which people get their night’s sleep may not be ideal for a disruption-free sleep. In contrast, when they were allowed to rest in a comfortable disruption-free environment at the workplace, they might have derived greater benefits from it.
