Studies and Research
Twelve Workplace Napping Research Studies From Around The World
School of Medicine, Flinders University, Adelaide, SA, Australia.
"For most
individuals, even those working permanent night shift, the circadian system is
in sleep mode during the night. The picture emerging is similar to afternoon
studies... the 10 minute sleep (about a 15 minute nap opportunity) produced
improvements over the 3 hour post-nap period in all eight alertness and
performance measures" 1
Karolinska Institute, Stockholm, Sweden.
"The nap brought performance to baseline levels, and subjective sleepiness
decreased significantly. It was concluded that the short nap had a clear positive
effect on alertness." 2
School of Psychology, Flinders University, Adelaide, SA, Australia
"The aim of the study was to investigate the recuperative value of brief and ultra-brief
naps following nocturnal sleep restriction. Consistent with our previous study (Tietzel
and Lack 2001), the 10-min nap resulted in significantly improved alertness and
cognitive performance relative to a no-nap control." 3
Department of Behavioral Sciences, Faculty of Integrated Arts and Sciences,
Hiroshima University, Higashi-hiroshima, Japan.
"All of the subjects were
awakened from sleep stage 2 during the nap. The 20 min nap improved the
subjective sleepiness, performance level and self-confidence of their task
performance .The results suggest that a short 20 min nap in the midafternoon had
positive effects upon the maintenance of the daytime vigilance level." 4
"The effects of a 20-min nap during 2 h of visual display terminal (VDT) work were examined. A 20-min nap maintained subjective alertness and performance level at a higher level and mental fatigue at a lower level for the additional 1 h of work. These results suggest that a short nap would be useful to both fatigue recovery and fatigue prevention during continuous VDT work." 5
"The effects of a short nap against mid-afternoon sleepiness could be enhanced by combining caffeine intake, exposure to bright light, or face washing. The present study would provide effective countermeasures against mid-afternoon sleepiness and sleepiness related accidents." 6
NASA Ames Research Center, Moffett Field, California, USA.
"Studies have demonstrated the effectiveness of naps to improve subsequent
performance and alertness. Strategic naps can be used effectively to promote
safety, performance, and productivity in operational settings." 7
New Zealand Environmental and Occupational Health Research Center, Department
of Preventive and Social Medicine, University of Otago, Dunedin, New Zealand.
"The purpose of this workplace evaluation was to assess the effects on performance,
alertness and subsequent sleep of strategic napping on 12-h overnight shifts. The
results revealed that taking a single 20-min nap during the first night shift significantly
improved speed of response on a vigilance task measured at the end of the shift
compared with the control condition." 8
Sleep Medicine and Research Center La Jolla, California, USA.
"Napping plus caffeine helps improve performance and alertness of night-shift
workers." 9
Nagoya City University Graduate School of Medical Sciences, Japan.
"Nighttime napping is an effective measure to prevent adverse effects due to night
shift work. A characteristic of the activity is using action checklist and group work,
and heightening motivation to improvement working condition between worker and
manager. Through the activities, (a) nighttime napping strategy would be spread
more in the workplaces and play a role as one of the effective tools for improving
working conditions, work performance and safety in the future." 10
Center of Sleep Medicine, University of Genoa, Italy.
"As naps are a countermeasure to sleepiness, this study evaluates the role they play
in preventing sleep-related accidents in Italian shift-working police drivers… the
theoretical efficacy of napping was quantified (by a) 48% accident decrease. Our
data seem to confirm that napping before working a night shift is an effective
countermeasure to alertness and performance deterioration associated with night
work." 11
Department of Epidemiology, Harvard School of Public Health, Boston USA
"...researchers tracked 23,681 healthy Greek adults for an average of about six years.
Those who napped for about half an hour at least three times weekly had a 37
percent lower risk of dying from heart attacks or other heart problems than those who
did not nap." 12
REFERENCES
1. R Doug McEvoy and Leon L Lack. Medical staff working the night shift: can
naps help? Medical Journal
of Australia 2006; 185 (7): 349-350
2. Gillberg, M, Kecklund, G., Axelesson, J. and Akerstedt, T. The effects of a
short daytime nap after
restricted night sleep. Sleep 1996,19(7) : 570-575.
3. Amber J. Tietzel and Leon C. Lack. The recuperative value of brief and
ultra-brief naps on alertness and cognitive performance. Journal of Sleep Research Page 213! - September, 2002
Volume 11 Issue three.
4. Hayashi M, Watanabe M, Hori T. The effects of a 20 min nap in the
mid-afternoon on mood, performance and EEG activity. Clin Neurophysiol. Feb 1999;110(2):272-9.
5. Mitsuo Hayashi, Youhei Chikazawa, Tadao Hori. Short nap versus short rest:
recuperative effects during VDT work. Taylor & Francis, Volume 47, Number 14 / November 2004, 1549 - 1560
6. Hayashi M, Masuda A, Hori T. Clin Neurophysiol. The alerting effects of
caffeine, bright light and face washing after a short daytime nap. Dec 2003;114(12):2268-78.
7. Rosekind MR, Smith RM, Miller DL, Co EL, Gregory KB, Webbon LL, Gander PH,
Lebacqz JV. Alertness management: strategic naps in operational settings.J Sleep Res. Dec
1995;4(S2):62-66.
8. Purnell MT, Feyer AM, Herbison GP. J Sleep Res. The impact of a nap
opportunity during the night shift on the performance and alertness of 12-h shift workers. Sep 2002;11(3):219-27.
9. Schweitzer PK, Randazzo AC, Stone K, Erman M, Walsh JK. Sleep. Laboratory and
field studies of naps and caffeine as practical countermeasures for sleep-wake problems associated
with night work. Jan 2006;
1;29(1):39-50.
10. Takeyama H, Kubo T, Itani T. Ind Health. The nighttime nap strategies for
improving night shift work in
workplace. Jan 2005;43(1):24-9.
11. Garbarino S, Mascialino B, Penco MA, Squarcia S, De Carli F, Nobili L,
Beelke M, Cuomo G, Ferrillo F. Professional shift-work drivers who adopt prophylactic naps can reduce the risk
of car accidents during night work. Sleep. Dec 2004;15;27(8):1446-8.
12. Androniki Naska, PhD; Eleni Oikonomou, BS; Antonia Trichopoulou, MD;
Theodora Psaltopoulou, MD; Dimitrios Trichopoulos, MD Siesta in Healthy Adults and Coronary Mortality in the General Population. Arch
Intern Med. 2007;167:296-301.
