UBC Undergraduate Research

Nap Duration & Psychological Outcomes for Students Tsunoi, Anna; Wu, Michael; Hui, Ricky; Lee, Winnie 2019-04-04

Your browser doesn't seem to have a PDF viewer, please download the PDF to view this item.

Notice for Google Chrome users:
If you are having trouble viewing or searching the PDF with Google Chrome, please download it here instead.

Item Metadata


18861-Tsunoi_A_et_al_PYSC_321_Nap_duration_ModernLobster_final_report.pdf [ 1.9MB ]
JSON: 18861-1.0387192.json
JSON-LD: 18861-1.0387192-ld.json
RDF/XML (Pretty): 18861-1.0387192-rdf.xml
RDF/JSON: 18861-1.0387192-rdf.json
Turtle: 18861-1.0387192-turtle.txt
N-Triples: 18861-1.0387192-rdf-ntriples.txt
Original Record: 18861-1.0387192-source.json
Full Text

Full Text

Running head: NAP DURATION & OUTCOMES      1 UBC Social Ecological Economic Development Studies (SEEDS) Sustainability Program Student Research Report        Nap Duration & Psychological Outcomes for Students The Modern Lobster: Anna Tsunoi, Michael Wu, Ricky Hui, & Winnie Lee University of British Columbia PSYC 321 Themes: Buildings, Health, Wellbeing April 4, 2019         Disclaimer: “UBC SEEDS Sustainability Program provides students with the opportunity to share the findings of their studies, as well as their opinions, conclusions and recommendations with the UBC community. The reader should bear in mind that this is a student research project/report and is not an official document of UBC. Furthermore, readers should bear in mind that these reports may not reflect the current status of activities at UBC. We urge you to contact the research persons mentioned in a report or the SEEDS Sustainability Program representative about the current status of the subject matter of a project/report”.  NAP DURATION & OUTCOMES        2 Executive Summary With the upcoming implementation of napping facilities on the UBC Vancouver campus for the Arts Students’ Centre, we sought to better understand the current sleep and napping habits of UBC students and if a length of nap was had an association with scores subjective psychological outcomes, whether positive or negative. We hypothesize that nap length should show some relationship with psychological outcomes. Through online survey, 55 participants that identified as UBC students were asked to self-report their average length of nap and the perceived frequency of experiencing several psychological outcomes as a result of their nap. Psychological outcomes were defined as positively or negatively valenced experiences/states such as alertness, readiness to work, feeling energized, satisfaction, fatigue, irritability, and anxiousness. Analysis using Spearman’s Rank Correlation Coefficient showed no significant correlations between nap length and any of the variables, as correlations were both extremely weak and not statistically significant.   Keywords: napping, sleep, psychology, university students, affect, surveys and questionnaires, correlational analysis         NAP DURATION & OUTCOMES        3 Nap Duration & Psychological Outcomes for Students Introduction Previous studies on napping have shown the effect of ‘’power nap’’(I.e., short session of sleep) to be beneficial for a number of outcomes, such as reducing fatigue 1 and improving performance based on accuracy and reaction time2. A different study found that a 20 minute nap in the mid-afternoon improved performance level and self-confidence on task performance3.  However a study examining Australian university student’s napping behaviour found that, compared to students that did not nap, students that did nap had worse daytime functioning. A majority of these nappers (77%) were found to take naps for longer than 30 minutes 4. So, research on nap length shows mixed results, but indicates a potential relationship between time and beneficial effects from napping.  Based on the results of the previous studies, we expect to find a relationship between nap duration and perceived psychological outcomes in the UBC student population as well. With the data obtained through our experiment, we hope to contribute to the planning and implementation of nap pods that would be beneficial for the UBC students.   Research question In our study, we hope to examine the sleep and nap habits of students at the University of British Columbia (such as how long they nap for), and what is the relationship between nap duration and psychological outcomes?  Hypothesis Our hypothesis for this study is that the data should show some relationship between nap duration and perceived psychological outcomes (e.g. alertness, fatigue) through correlational analysis.  Method Participants Fifty-five students from the University of British Columbia were surveyed for our study. 29 identified as women, 25 identified as men, and 1 unspecified. 53 were currently undergraduate students, 1 was a graduate student, and 1 was pursuing a professional degree. Ages ranged from 18 to 23 years old (M = 20.7, SD = 1.1).   Among this sample, the most common amount of sleep per night in hours was 7 hours (n = 22), with amounts ranging from 4 to 9 hours (M = 6.8, SD = 1.0). Regularity of napping in an average month was assessed through self-report on a subjective scale ranging from “never”, “occasionally”, “once a week”, “several days a week”, amd “everyday”. The majority of participants reported napping “occasionally” (n = 20), which we defined as a only a few days a month; in decreasing order of popularity the rest of the participants reported napping “several days a week” (n = 14), “once a week” (n = 12), “never” (n = 5), and “everyday” (n = 4).  Measures  With the intent of utilizing a correlational research design, an online self-report survey was created via Google Forms to assess 1) student sleep and nap behaviours and preferences, and 2) student demographics.  The main variables of interest for our study were seven perceived psychological outcomes: fatigue, alertness, readiness to work, energized, irritable, satisfied, and anxious. We believed that these moods would be most pertinent for a student’s well-being, without significant NAP DURATION & OUTCOMES        4 conceptual overlap that could causes any confusion as to their definitions. We assessed the frequency of occurrence of these outcomes from napping through the question: “Thinking About How You Feel Before And After A Nap, Rate How You Tend To Feel After A Nap”, with responses on a scale ranging from “not at all”, “rarely”, “sometimes”, “often”, and “always”.   Conditions Though all participants received the same survey, for our analysis of nap length we had participants identify approximately how long their naps tended to be on average by indicated which range of nap length they best identified with, to create conditions to study. Ranges under an hour spanned 9 minute periods (E.g., 0-9 minutes, 20-29 minutes), while ranges over an hour spanned 1 hour periods (I.e., 1-2 hours, 2-3 hours, or +3 hours for naps exceeding the previous ranges). Ranges were preferred over asking for specific measurements of time under the assumption that participants were more likely to report rough estimates of their nap length, rather than know exactly how many minutes they napped for.    Procedures  All participants were given a link to the online survey, to fill in on their own time. A majority of participants were recruited through social media (I.e., Facebook), with the remaining participants contacted through the researchers’ social networks. Responses to the survey were collected until March 19, 2019 at 11:59pm. Results from the survey were then coded to make numerical analysis possible, with nap length responses being coded from 1 to 9, with 1 being our smallest nap range (0-9 minutes) and 9 being our largest nap range (+3 hours). Psychological outcome frequency was coded from 1 to 5, with 1 being our smallest frequency (“not at all”) and 5 being our largest frequency (“always”). Data was first plotted onto scatter plot graphs to create a visual depiction before being analyzed through Spearman’s rank order correlation to determine the potential strength and linear relationship between nap length and the psychological outcomes.   Results The most common nap duration as reported by our participants is 1-2 hrs (n = 12, 23.5% of the sample population), followed by 10-19 mins (n  = 9, 17.6% of the sample population). From the scale of 1 to 5 (1 = not at all, 5 = all the time), participants reported that after their nap the average frequency of feeling alert was 3.12 (SD = .89), the average frequency of feeling ready to work was 3.29 (SD = .88), the average frequency of feeling energized was 3.35 (SD = .84), the average frequency of feeling satisfied was 3.29 (SD = .88), the average frequency of feeling fatigue was 2.71 (SD = .83), the average frequency of feeling irritable was 2.27 (SD = .96), and the average frequency of feeling anxious was 1.88 (SD = .93). We used Spearman’s rho to measure the correlation between reported nap duration and the average frequency of feeling each of the 7 psychological outcomes resulted by napping. The outcome showed that there are no significant correlation between alertness and nap duration (rs(49) = .08, p = .56), no significant correlation between ready to work and nap duration (rs(49) = -.15, p = .29), no significant correlation between energized and nap duration (rs(49) = -.13, p = .38), no significant correlation between satisfied and nap duration (rs(49) = .01, p = .97), no significant correlation between fatigue and nap duration (rs(49) = -.16, p = .27), no significant correlation between irritable and nap duration (rs(49) = .01, p = .96), and no significant correlation between anxious and nap duration (rs(49) = -.06, p = .68).  NAP DURATION & OUTCOMES        5 None of the results were statistically significant enough to show a correlation between nap duration and any psychological outcomes, with p > .05 for all the hypothesis tests.  Discussion  When we first began looking for correlations between nap duration and each of the perceived psychological outcomes, we made a series of scatterplots (see Appendix, Figure 1-7), but patterns were not clear to see from looking at the graphs. We then ran the data through Spearman’s Rank-Order Correlation tests to discover the strength and direction of the monotonic relationships between our variables. As expected, none of pairs showed any sort of significant correlation, just as the scatterplots suggested.   When we created the survey, our main way of assessing nap duration was by asking,  “Approximately, how long do these naps tend to be?”. Originally, we wanted the participants to report their responses in terms of precise minutes (e.g. 4 minutes, 110 minutes), but we decided against it from the understanding that participants won’t be able to report the exact time of their nap durations. Thus, we changed the response options to be categorical ranges of time (e.g. 0-9 minutes, 1-2 hrs) that participants would estimate their naps tend to fall into. The result of such change affected the way our scatterplots were presented, as a lot of the data points overlapped instead of being clustered. This is one of the explanations for why correlations were not observed in our scatterplots.  Overall, the results of our study suggest that there were no significant relationships between the nap duration and perceived psychological outcomes tested. All Spearman's rho values were close to 0, which indicate that the correlations were very weak (I.e., close to no relationship). The p-values were all above 0.05, which indicate that our data is not statistically significant. Thus, it could be said that the results do not support our hypothesis, which was that we would find a relationship between nap duration and perceived psychological outcomes.  It was suggested to our group that we run a post-hoc analysis on our data to see if there were potential curvilinear relationships between nap length and the outcomes. To facilitate this we first grouped nap lengths into three groups: “low duration” (encompassing naps 0-9, 10-19, and 20-29 minutes long), “medium duration” (encompassing naps 30-39, 40-49, and 50-59 minutes long), and “high duration” (encompassing naps 1 hour, 2-3 hours, or more than 3 hours long). We then ran the data through one-way ANOVA to see if the differences in mean scores between the groups could show a pattern suggestive of a relationship. We would predict that if there were potential curvilinear relationships in the data that graphs should show inverted u-shapes for scores on the positive outcomes and upright u-shapes for the negative outcomes. Though some graphs did show u-shaped patterns (like the inverted u seen in the data for anxiousness and irritability), the direction of the u-shape did not align with our expectations and results of this analysis were still statistically insignificant for all the outcomes. So, we still cannot use our data to reject the null hypothesis (see Figure 10 and Table 2 in the appendix for more details).     There are several limitations to our research. First, our survey only had 55 participants who were mainly recruited through social media and convenience sampling (I.e., our peers), so the representativeness is questionable and our study was underpowered. Second, our measures were based on self-reported feelings or experiences of nap outcomes, so the data obtained may NAP DURATION & OUTCOMES        6 be unreliable. To obtain a more reliable data, psychological outcomes of naps would need to be studied experimentally with validated constructs (e.g. having participants actually take naps, using devices capable of measuring brain activity in regions associated with affective responses). Third, our psychological outcome constructs lacked clarity. For example, psychological constructs such as "alertness" is subjective, and thus the measure lacks consistency between subjects. In other words, the understanding of the constructs used may vary for each participant. As well, it may not have been clear to our participants that our question to gauge the psychological outcomes was meant to assess how often napping resulted in that outcome being brought about, rather than assessing to what degree one felt that outcome as a result of napping.   We believe that activity performed before and after a nap may serve as an alternative explanation for/directly affect the perceived psychological outcomes. Intuitively speaking, you may experience more negative psychological outcomes if you had a stressful event (E.g., a midterm) right after your nap, as opposed to having a pleasurable experience (E.g., a friendly gathering). These situational factors were hard to eliminate from our survey study, and therefore may be affecting the accuracy of our results. We suggest future studies to focus on designing an experimental study run at several points throughout the year (to account for situational factors/time of measurement effects) to discover a more accurate relationship between nap duration and perceived psychological outcomes.  Recommendations for client Although the survey we conducted did not show any correlations between nap duration and psychological outcomes, there are recommendations we can make based on our research. First, as 36.4% of our participants reported that they take naps occasionally (a few days per month) and 25.5% reported that they take naps several days a week, it could still be said that the implementation of nap pods will be beneficial for the UBC students. Regardless of whether the naps leads to better psychological outcomes, the nap pods will be widely used by students. The majority of participants of our study reported that their nap duration tends to be 1 to 2 hours or any time less than an hour, and that they often nap in the afternoon.  However, in contrast to our survey findings (in our prior literature review on the research that has already been done) we found that a nap duration of 20 minutes was the most effective, as it lead to improved performance levels and self-confidence on task performances.  Thus, when implementing the nap pods, each nap period could be timed, as this would lead to better nap outcomes and more efficient use of the facility. For example, each nap period could be set from any time between 0 to 1 hour, to account for individual preferences. Further, the main operation hours for the nap pods could be 1 pm to 5 pm for example, as most students reported taking naps in the afternoon.        NAP DURATION & OUTCOMES        7 Appendix  References  1Brooks, A., & Lack, L. (2006). A brief afternoon nap following nocturnal sleep restriction: Which nap duration is most recuperative? Sleep, 29(6), 831-840. doi:10.1093/sleep/29.6.831  2Kuriyama, A., Ogawa, K., & Hayashi, M. (2014). Sleep spindle contributes to the recuperative power of a short nap. International Journal of Psychophysiology, 94(2), 224-224. doi:10.1016/j.ijpsycho.2014.08.883  3Hayashi, M., Watanabe, M., & Hori, T. (1999). The effects of a 20 min nap in the mid-afternoon on mood, performance and EEG activity. Clinical Neurophysiology, 110(2), 272-279. doi:10.1016/s1388-2457(98)00003-0  4Lovato, N., Lack, L., & Wright, H. (2014). The napping behaviour of australian university students. PloS One, 9(11), e113666. doi:10.1371/journal.pone.0113666    NAP DURATION & OUTCOMES        8   NAP DURATION & OUTCOMES        9    NAP DURATION & OUTCOMES        10  NAP DURATION & OUTCOMES        11   Figure 8: Summary of nap and sleep behaviour of UBC students. (A) hours of sleep per night on average, (B) average frequency of nap within a month, (C) preferred location on campus to nap, (D)  preferred location off campus to nap, (E) preferred time of day to nap, (F) nap length, (G) preferred activity prior to napping, & (H) preferred activity after napping.      (A)       (B)  (C) Preferred on campus locations responses: sitting areas, study spaces, eating areas, parkade/outside areas, friend’s dorm, library sofas, lounge, aquatic centre.  (D) Preferred off campus location responses: in a bed, on a couch, during commute/in transportation, in a car.   NAP DURATION & OUTCOMES        12  (E)       (F)  (G) Preferred activity prior to napping responses: studying, using media, exercising, class or work, get up and go to school.    (H) Preferred activity after napping responses: studying, using media, exercise, chores, eating.    Figures 9: Summary of the demographic breakdown of our sample. (A) Gender, (B) student status, (C) year of study, (D) age in years, (E) primary place of residence during the school year, & (F) grade point average estimation.       (A)       (B)  NAP DURATION & OUTCOMES        13     (C)      (E)  (D)   (F)   NAP DURATION & OUTCOMES        14 Figures 10: Results of Post-Hoc Analysis on the data using one-way between subjects ANOVA. The nap length conditions from the data were grouped into three subsets (low, medium, high duration coded as 1, 2, 3, respectively) to see if there were any potential curvilinear relationships. Scores on psychological outcomes were coded from 0 to 5, with 0 representing a frequency of “not at all” and 5 representing a frequency of “always”. However, the results we did find through ANOVA were still statistically insignificant (p < .05). (A) Analysis of frequency of irritability, (B) analysis of frequency of readiness to work, (C) analysis of frequency of satisfaction, (D) analysis of frequency of feeling energized, (E) analysis of frequency of alertness, (F) analysis of frequency of fatigue, (G) analysis of frequency of anxiousness.       (A)      (B)      (C)      (D)      (E)      (F) NAP DURATION & OUTCOMES        15      (G)                                        NAP DURATION & OUTCOMES        16 Figure 11: Survey on nap duration. All participants were given this survey to fill out. Responses were meant to gauge sleeping and napping behaviours, and demographic information of current UBC Vancouver students.   NAP DURATION & OUTCOMES        17 NAP DURATION & OUTCOMES        18 NAP DURATION & OUTCOMES        19  NAP DURATION & OUTCOMES        20    NAP DURATION & OUTCOMES        21 Table 1: Summary of results from Spearman’s Rank Correlation Coefficient Analysis  Variables P-Value Spearman’s rho Alertness  .558 .084 Readiness to work .291 -.151 Energized .377 -.126 Satisfied .967 .006 Fatigue .266 -.159 Irritable .957 .008 Anxious .681 -.059   Table 2: Summary of results from post-hoc analysis using one-way between subjects ANOVA.   Variable F Value df P-Value Irritable 1.410 2 0.254 Ready to Work 0.183 2 0.834 Satisfied 0.062 2 0.940 Energized 0.285 2 0.754 Alert 1.218 2 0.305 Fatigue 1.741 2 0.186 Anxious 1.901 2 0.160  


Citation Scheme:


Citations by CSL (citeproc-js)

Usage Statistics



Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            async >
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:


Related Items