pre-printBackground: Extending Daylight Savings Time (DST) has been identified as a policy intervention that may encourage physical activity. However, there has been little research on the question of if DST encourages adults to be more physically active. Methods: Data from residents of Arizona, Colorado, New Mexico, and Utah ages 18-64 who participated in the 2003-2009 American Time Use Survey are used to assess whether DST is associated with increased time spent in moderate-to-vigorous physical activity (MVPA). The analysis capitalizes on the natural experiment created because Arizona does not observe DST. Results: Both bivariate and multivariate analyses indicate that shifting 1 hour of daylight from morning to evening does not impact MVPA of Americans living in the southwest. Conclusions: While DST may affect the choices people make about the timing and location of their sports/recreational activities, the potential for DST to serve as a broad-based intervention that encourages greater sports/recreation participation is not supported by this analysis. Whether this null effect would persist in other climate situations is an open question

Zick, Cathleen D.

English

The University of Utah: J. Willard Marriott Digital Library

1057The author is with Dept of Family and Consumer Studies, University of Utah, Salt Lake City, UT.Journal of Physical Activity and Health, 2014, 11, 1057-1060 http://dx.doi.org/10.1123/jpah.2012-0300 © 2014 Human Kinetics, Inc.Does Daylight Savings Time Encourage Physical Activity?Cathleen D. ZickBackground: Extending Daylight Savings Time (DST) has been identified as a policy intervention that may encourage physi-cal activity. However, there has been little research on the question of if DST encourages adults to be more physically active. Methods: Data from residents of Arizona, Colorado, New Mexico, and Utah ages 18–64 who participated in the 2003–2009 American Time Use Survey are used to assess whether DST is associated with increased time spent in moderate-to-vigorous physical activity (MVPA). The analysis capitalizes on the natural experiment created because Arizona does not observe DST. Results: Both bivariate and multivariate analyses indicate that shifting 1 hour of daylight from morning to evening does not impact MVPA of Americans living in the southwest. Conclusions: While DST may affect the choices people make about the timing and location of their sports/recreational activities, the potential for DST to serve as a broad-based intervention that encourages greater sports/recreation participation is not supported by this analysis. Whether this null effect would persist in other climate situations is an open question.Keywords: sports, recreation, public health interventionDaylight savings time (DST) legislation was originally moti-vated by its potential to reduce energy consumption1 but researchers have examined its implications for several health outcomes includ-ing workplace related accidents,2,3 health events,4–6 and the timing of sleep and work7 with mixed results. The strongest evidence of DST’s health consequences comes from studies that have linked it to reductions in automobile-related accidents.8–13Public health officials working to identify policies that might reduce adults’ obesity risks have recently begun to explore what role DST might play in people’s physical activity choices. Hill-man14,15 notes that the early onset of dusk during non-DST limits individuals’ accessibility to sports and recreation opportunities. If DST encourages greater sports/recreation participation, then extending DST could be viewed as a broad-based mechanism for increasing physical activity. Yet, to date there has been very little empirical testing of this proposition. Holmes et al16 provide pre-liminary confirmation of Hillman’s thesis as they find that urban pedestrian and nonmotorized vehicle trail traffic in Indianapolis significantly increased when DST began. In addition, Rosenberg and Wood,17 using data from Australia, find that DST is associated with a shift in the time of day when people exercise. Finally, Wolff and Makino18 use data from the 2005–2008 American Time Use Survey (ATUS) to examine how the extension of DST in 2007 may have altered indoor and outdoor leisure time. They report that the DST extension is linked to more time spent in outdoor leisure activities (eg, participating in sports, watching sports), and less time spent in indoor leisure activities (eg, watching television) between the hours of 3 PM to 7 PM.In the current study, 2003–2009 ATUS data are used to assess whether DST is associated with time spent in moderate-to-vigorous physical activity (MVPA). DST may impact both outdoor and indoor MVPA as more evening daylight hours may lead to the substitu-tion of outdoor MVPA for indoor MVPA. Both are included in our measure so we assess the net impact of DST on MVPA. The analysis capitalizes on the natural experiment created by the fact that Ari-zona does not observe DST. Arizona passed legislation exempting it from the 1967 Uniform Time Act because of high summertime temperatures. With the exception of the Navajo Nation, Arizona has not observed DST since 1968,19 while the surrounding southwestern states have observed DST.MethodsThe ATUS is an annual survey of Americans age 15 and older gath-ered over all 12 months of the year.20 Each respondent provides a 24-hour time diary which is considered to be a valid and reliable measure of time use.21–23 The current analysis focuses on diary reports of time spent in all activities that generate 3.0+ metabolic equivalent values (METs) which is the accepted threshold for moderate-to-vigorous physical activity (MVPA).24 Tudor-Locke et al25 have linked the ATUS time-use categories to the compendium of physical activity and we use their tables to identify the MVPA time-use categories. The categories that meet the MVPA threshold include activities such as exterior house cleaning, lawn and garden work, playing sports with household children, active transportation time (ie, walking or biking), as well as all forms of sports and exercise except billiards. (Some types of walking fall below the 3.0 METs threshold while others do not. We include all transportation related walking since we cannot always make meaningful distinctions using the ATUS.) The MVPA standard is used to measure physical activ-ity because the Centers for Disease Control and Prevention (CDC) recommends that adults devote at least 150 minutes per week to MVPA to attain/maintain a healthy body weight.24Analyses are restricted to adults age 18–64. American Indians are excluded because it cannot be determined from the ATUS as to whether they live within the Arizona Navajo Nation lands where they observe DST. Respondents are included if their dairy date falls between (a) the first Sunday in April and the last Sunday in October in the years 2003–2006, or (b) the second Sunday in March and the first Sunday in November in the years 2007–2009, as these dates reflect DST. Arizona respondents whose diary dates fall during Official Journal of ISPAHwww.JPAH-Journal.comORIGINAL RESEARCH1058  Zickthese intervals form the treatment group. Colorado, Utah, and New Mexico respondents whose diaries fall in these intervals form the control group. Colorado, Utah, and New Mexico are selected for comparison because these states are in the Mountain Time Zone and their physical geography and climates are similar to Arizona’s.Multivariate analyses control for the respondent’s sociodemo-graphic characteristics.20 For each state’s largest metropolitan area, daylight hours for the day of the diary26 and average monthly high temperature for the diary month27 are linked to the ATUS file and included as climate controls as past research has found that individu-als’ time use choices are linked to weather.28 Logistic regression is used to estimate the probability an individual spends time in MVPA activities on the diary day. A separate tobit regression, that makes adjustments for the censoring at zero minutes, is used to estimate time spent in MVPA. Analyses use the ATUS final weights to insure generalizability to the states in question. This study was deemed exempt by the University of Utah’s Institutional Review Board.ResultsTable 1 reveals that the average sample member is almost 40 years old, has some college education, is employed, white, married, has 1 child at home, and lives in a metro area. About one-third of the respondents (N = 820) live in Arizona. Only 27% of respondents report spending time in MVPA activities on the diary day and the average amount of time spent in MVPA is slightly less than 23 minutes. When the MVPA measure is restricted to sports/recreation activities only, the mean time is 20 minutes suggesting that most MVPA time is sports/recreation time. As points of comparison, the mean time spent in all sports/recreation activities for all Americans age 15 and older in the 2010 ATUS was a little more than 18 min-utes per day.20 Analyses that use the National Health and Nutrition Examination Survey’s (NHANES) accelerometer data report time spent in all MVPA averages 35 minutes per day for males and 21 minutes per day for females age 20–65.29 Thus, the time spent in MVPA by residents of the southwestern U.S. appears to mirror the national average as measured by time diary methods but, as expected, it is lower than what is reported using accelerometer data that more precisely measures all MVPA.Bivariate examinations of MVPA participation and time spent reveal no statistically significant differences by residential location. A little over 27% of Arizona respondents report spending some time in MVPA on the diary day while the corresponding percentage for residents of Colorado, Utah, and New Mexico is 26%. The average time spent in MVPA is 22 minutes for both groups.The multivariate analyses presented in Table 2 reveal that par-ticipation and total time devoted to MVPA is associated with gender, age, education, employment status, race/ethnicity, number of children, calendar year, and hours of daylight on the diary day. These findings are consistent with prior research.30–32 The likelihood of participation and the marginal increase in time spent in these activities rises significantly with the hours of daylight available. However, based Table 1 Weighted Descriptive Statistics for ATUS Respondents Age 18–64 Living in Arizona, Colorado, New Mexico, and Utah Whose Diary Day was Recorded During Daylight Savings TimeVariableFull sample (N = 2411) mean/proportionNon-zero MVPA sample (N = 642) mean/proportionParticipates in any MVPA (1 = yes) .27 1.0Minutes spent in MVPA 22.58 70.71Female (1 = yes) .50 .49Age (yrs) 39.80 39.23Education (yrs) 13.64 14.10Employed (1 = yes) .80 .77White non-Hispanic (1 = yes) .71 .77Black non-Hispanic (1 = yes) .03 .02Hispanic (1 = yes) .23 .17Asian (1 = yes) .02 .03Other race/ethnicity (1 = yes) .01 .01Married (1 = yes) .60 .57Number of minor children in home .98 .87Weekend or holiday diary day (1 = yes) .27 .27Diary year (2003 = 1 . . . 2009 = 8) 4.72 4.48Lives in a metro area (1 = yes) .77 .81Average monthly high temperature (degrees Fahrenheit) 81.73 82.72Hours of daylight on diary day 13.30 13.41AZ resident (1 = yes) .34 .35CO, NM, or UT resident (1 = yes) .66 .65Abbreviations: MVPA, moderate-to-vigorous physical activity; ATUS, American Time Use Survey.Source: American Time Use Survey, 2003–2009.Daylight Savings Time and PA  1059on the estimated coefficients associated with the Arizona resident variable, we do not find that DST is associated with either the odds of participating in MVPA or the time spent in these activities.ConclusionsWhile DST may affect the choices people make about the timing and location of their MVPA,16,17 the potential for DST to serve as a broad-based intervention that encourages greater MVPA is not sup-ported by this analysis. The empirical work holds hours of sunlight for the diary day and average high temperature for the diary month constant. Thus, the primary effect captured by treatment versus control group membership is the timing of sunrise and sunset. It would appear that shifting 1 hour of daylight from the morning to the evening has no impact on the MVPA of American adults living in the southwest.It may be that DST serves to shift MVPA time from indoors to outdoors or from morning to afternoon/evening. It may also be that DST effects are climate specific. For instance, the effects may vary at other latitudes, during the winter months, or in parts of the country that have more inclement weather. All of the above are “open questions” that merit future research.References 1. Pavlus J. Daylight Savings Time. Sci Am. 2010;303(3):69–69. 2. Lahti T, Sysi-Aho J, Haukka J, Partonen T. Work-related accidents and daylight saving time in Finland. Occup Med (Lond). 2011;61(1):26–28. PubMed doi:10.1093/occmed/kqq167 3. Morassaei S, Smith PM. Switching to Daylight Saving Time and work injuries in Ontario, Canada: 1993-2007. Occup Environ Med. 2010;67(12):878–880. PubMed doi:10.1136/oem.2010.056127 4. Janszky I, Ahnve S, Ljung R, et al. Daylight saving time shifts and incidence of acute myocardial infarction–Swedish Register of Informa-tion and Knowledge About Swedish Heart Intensive Care Admissions (RIKS-HIA). Sleep Med. 2012;13(3):237–242. PubMed doi:10.1016/j.sleep.2011.07.019 5. Lahti TA, Haukka J, Lönnqvist J, Partonen T. Daylight saving time transitions and hospital treatments due to accidents or manic episodes. BMC Public Health. 2008;8:74–77. PubMed doi:10.1186/1471-2458-8-74 6. Olders H. Average sunrise time predicts depression prevalence. J Psychosom Res. 2003;55(2):99. PubMed doi:10.1016/S0022-3999(02)00479-8 7. Hamermesh DS, Myers CK, Pocock ML. Cues for timing and coordination: latitude, letterman, and longitude. J Labor Econ. 2008;26(2):223–246. doi:10.1086/525027 8. Adams J, White M, Heywood P. Year-round daylight saving and serious or fatal road traffic injuries in children in the north-east of England. J Public Health (Oxf). 2005;27(4):316–317. PubMed doi:10.1093/pubmed/fdi047 9. Coate D, Markowitz S. The effects of daylight and daylight saving time on US pedestrian fatalities and motor vehicle occupant fatalities. Table 2 Weighted Parameter Estimates of Multivariate Analyses Based on ATUS Respondents Age 18–64 Living in Arizona, Colorado, New Mexico, and Utah Whose Diary Day was Recorded During Daylight Savings TimeVariableOdds ratios of MVPA participation (95% CI)Tobit coefficients for MVPA tme (t-ratios)Tobit marginal effectsbIntercept — –318.17 (–5.30)* —Female .81 (.65–1.02) –33.06 (–3.97)* –7.71Age .99 (.98–.99)* –1.31 (–3.66)* –.33Education 1.13 (1.07–1.19)* 8.28 (4.19)* 2.13Employed .62 (.47–.81)* –42.78 (–4.11)* –11.01Black non-Hispanica .56 (.27–1.16) –58.29 (–2.17)* –15.00Hispanica .67 (.50–.91)* –34.52 (–3.16)* –8.89Asiana 1.52 (.74–2.84) 42.73 (1.72) 11.01Other race/ethnicitya .54 (.15–1.98) –33.16 (–.74) –8.54Married .89 (.69–1.15) –12.34 (–1.31) –3.18# Minor children .91 (.82–1.01) –7.93 (–2.19)* –2.04Weekend/holiday .98 (.77–1.25) 6.78 (.75) 1.75Diary year (2003 = 1 . . . ) 1.11 (1.05–1.17)* 7.39 (3.54)* 1.90Lives in a metro area 1.31 (.99–1.72) 12.44 (1.22) 3.20Average monthly high temperature 1.01 (1.00–1.02) .34 (1.08) .09Hours of daylight on diary day 1.09 (.99–1.21)* 11.87 (3.24)* 3.06Arizona resident (1 = yes) 1.00 (.74–1.33) 1.28 (.12) .33Pseudo R2 .06 .02Abbreviations: MVPA, moderate-to-vigorous physical activity; ATUS, American Time Use Survey.* P < .05, Source: American Time Use Survey, 2003-2009.a The omitted group in this sequence of dummy variables are those respondents who identified their race/ethnicity as White non-Hispanic.b Calculated at the mean/modal values for all of the independent variables.1060  ZickAccid Anal Prev. 2004;36(3):351–357. PubMed doi:10.1016/S0001-4575(03)00015-0 10. Ferguson SA, Preusser DF, Lund AK, Zador PL, Ulmer RG. Daylight Saving Time and motor vehicle crashes: the reduction in pedestrian and vehicle occupant fatalities. Am J Public Health. 1995;85(1):92–95. PubMed doi:10.2105/AJPH.85.1.92 11. Huang A, Levinson D. The effects of daylight saving time on vehicle crashes in Minnesota. J Safety Res. 2010;41(6):513–520. PubMed doi:10.1016/j.jsr.2010.10.006 12. Lahti T, Nysten E, Haukka J, Sulander P, Partonen T. Daylight saving time transitions and road traffic accidents. J Environ Public Health. 2010;2010:657167-657167. 13. Sood N, Ghosh A. The short and long run effects of Daylight Saving Time on fatal automobile crashes. B.E. Journal of Economic Analysis and Policy: Contributions to Economic Analysis and Policy. 2007;7(1):1–20. 14. Hillman M. Making the most of daylight hours: the implications for Scotland. London, England: Policy Studies Institute, University of Westminister; 2010. 15. Hillman M. More daylight, better health: why we shouldn’t be put-ting the clocks back this weekend. BMJ. 2010;341:c5964. PubMed doi:10.1136/bmj.c5964 16. Holmes A, Lindsey G, Qiu C. Ambient air conditions and variation in urban trail use. J Urban Health. 2009;86(6):839–849. PubMed doi:10.1007/s11524-009-9398-8 17. Rosenberg M, Wood L. The power of policy to influence behaviour change: daylight saving and its effect on physical activity. Aust N Z J Public Health. 2010;34(1):83–88. PubMed doi:10.1111/j.1753-6405.2010.00479.x 18. Wolff H, Makino M. Extending Becker’s time allocation theory to model continuous time blocks: evidence from daylight saving time. Dis-cussion Paper series, Forschungsinstitut zur Zukunft der Arbeit;2012. 19. Daylight Saving Time. 2009; http://www.lib.a.us/links/daylight.aspx. Accessed June 30, 2012. 20. Bureau of Labor Statistics. American Time Use Survey–Multi-Year Microdata Files. American Time Use Survey 2012; http://www.bls.gov/tus/datafiles_0310.htm. Accessed June 10, 2012. 21. Bianchi SM, Robinson JP, Milkie MA, eds. Changing rhythms of American family life. New York: Russell Sage Foundation; 2006. 22. Robinson JP. The validity and reliability of diaries versus alternative time use measures. In: Juster FT, Stafford FP, eds. Time, goods, and well-being. Ann Arbor, MI: Institute for Social Research, University of Michigan; 1985:33–62. 23. Robinson JP, Bostrom A. The overestimated workweek? What time diary measures suggest. Mon Labor Rev. 1994;117(8):11–23. 24. Centers for Disease Control and Prevention. How Much Physical Activity Do Adults Need? 2011; http://www.cdc.gov/physicalactivity/everyone/guidelines/adults.html. Accessed December 17, 2012. 25. Tudor-Locke C, Washington TL, Ainsworth BE, Troiano RP. Link-ing the American Time Use Survey (ATUS) and the Compendium of Physical Activities: methods and rationale. J Phys Act Health. 2009;6(3):347–353. PubMed 26. United States Naval Observatory. Duration of Daylight/Darkness Table for One Year. 2012; http://aa.usno.navy.mil/data/docs/Dur_OneYear.php/. Accessed June 28, 2012. 27. National Weather Service. Average Monthly High Temperatures. 2012; www.wrh.noaa.gov. Accessed June 15, 2012. 28. Connolly M. Here comes the rain again: weather and the intertem-poral substitution of leisure. J Labor Econ. 2008;26(1):73–100. doi:10.1086/522067 29. Luke A, Dugas LR, Durazo-Arvizu RA, Cao G, Cooper RS. Assess-ing physical activity and its relationship to cardiovascular risk fac-tors: NHANES 2003-2006. BMC Public Health. 2011;11(Suppl 4):387–397. PubMed doi:10.1186/1471-2458-11-387 30. Carlson SA, Fulton JE, Schoenborn CA, Loustalot F. Trend and prevalence estimates based on the 2008 Physical Activity Guide-lines for Americans. Am J Prev Med. 2010;39(4):305–313. PubMed doi:10.1016/j.amepre.2010.06.006 31. Dunton GF, Berrigan D, Ballard-Barbash R, Graubard BI, Atienza AA. Social and physical environments of sports and exercise reported among adults in the American Time Use Survey. Prev Med. 2008;47(5):519–524. PubMed doi:10.1016/j.ypmed.2008.07.001 32. Tucker JM, Welk GJ, Beyler NK. Physical activity in U.S. adults: compliance with the Physical Activity Guidelines for Americans. Am J Prev Med. 2011;40(4):454–461. PubMed doi:10.1016/j.amepre.2010.12.016

Does daylight savings time encourage physical activity?

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Does daylight savings time encourage physical activity?

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