Active Livig Research Buildig Evidece to Prevet Childhood Obesity ad Support Active Commuities www.activelivigresearch.org RESEARCH BRIEF February 2013 Do Short Physical Activity Breaks i Classrooms Work? Itroductio Childhood obesity has reached epidemic proportios i the Uited States. Almost 17 percet of childre ad tees more tha 12 millio youg people are obese. 1, 2 Physical activity ca help childre ad tees maitai a healthy weight, but atioal studies show low levels of physical activity amog childre ad tees. 3 6 School-aged childre sped more tha half of their wakig hours at school, 7 makig schools a prime locatio to icrease physical activity amog childre. There are several evidece-based strategies for icreasig physical activity at school. 8 Creatig activity breaks at school, such as movig ad steppig for up to 20 miutes at a time i the classroom durig the school day, is a relatively ew ad iovative method for icreasig physical activity amog childre. Several activity break programs already are available for teachers to use with childre at differet ages, ad may of them have bee evaluated. This brief summarizes A atioal program of the Robert Wood Johso Foudatio, with directio ad techical assistace provided by the Uiversity of Califoria, Sa Diego.
Active Livig Research RESEARCH BRIEF February 2013 page 2 the research o how programs that provide classroom physical activity breaks impact physical activity, o-task behavior, health, ad related factors i childre. This brief focuses o activity breaks coducted i the classroom, ad does ot cover physical educatio classes, recess, or physical activity breaks outside of schools. Program Defiitios Istat Recess uses culturally saliet music ad moves to ecourage physical activity i 10-miute bouts throughout the school day. Materials for this program are available at: www.joureyworks.com/nutritio-physical- Activity/products/206/. Physical Activity Across the Curriculum (PAAC), somewhat similar to TAKE 10!, promotes 90 miutes per week of active academic lessos through moderate-tovigorous physical activity i a study of 24 elemetary schools i Kasas. 13 TAKE 10! icorporates grade-specific activities liked to core curriculum objectives for mathematics, sciece, laguage arts, social studies, ad character educatio i 10-miute segmets. 9 Materials for this program are available at: www.take10.et. The Eergizers program, based o TAKE 10!, allows studets to stad ad move i 10-miute itervals durig classroom istructio usig grade-appropriate, teacher-led activities. 10 Materials for this program are available at: www.ecu.edu/cs-hhp/exss/upload/eergizers_ for_grades_k_2.pdf. Texas I-CAN icorporates movemet ito regular classroom lessos (e.g., math, laguage arts, sciece, social studies, ad health), i 10 15 miute bouts, to achieve academic curricular goals. 14 Teachers are provided with a full day of traiig at the begiig of the program, ad a half-day refresher i the middle of the school year. The Makig the Grade with Diet ad Exercise program for elemetary school studets icludes participatio i 10 20 miutes of teacher-led physical activity at the begiig of each school day. Happy 10, also based o TAKE 10!, ecourages classroom-based, teacher-led physical activity for 10 miutes at least oce per school day. 11 The Promotig Lifestyle Activity for Youth (PLAY) program focuses o teachig childre i grades 4 through 6 active lifestyle habits ad ecourages accumulatio of 30 to 60 miutes of moderate-to-vigorous physical activity daily. 12 PLAY icludes a 15-miute break for physical activity durig the school day. Activity Bursts i the Classroom for Fitess (ABC for Fitess) ecourages structured physical activity durig the time teachers would ordiarily sped settlig studets dow or gettig studets back o task. Activity bursts, spread throughout the day, iclude a warm-up, a core stregth or aerobic activity, ad a cool-dow. The legth ad umber of activities varies. A atioal program of the Robert Wood Johso Foudatio, with directio ad techical assistace provided by the Uiversity of Califoria, Sa Diego. activelivigresearch.org
Active Livig Research RESEARCH BRIEF February 2013 page 3 Key Research Results Providig short physical activity breaks durig the school day icreases physical activity i studets Istat Recess was evaluated by direct observatio i 3rd, 4th ad 5th grade classrooms i eight elemetary schools i Wisto-Salem, N.C. 15 Teachers were traied i a half-day workshop ad acted as champios to ecourage use by other teachers. After implemetig Istat Recess, itervetio schools showed sigificat icreases i light- (51%) ad moderate-itesity (16%) classroom-based physical activity. Cotrol schools did ot show sigificat icreases i classroom physical activity itesity util after they bega implemetig Istat Recess. There was a direct correlatio betwee teacher self-reported ethusiasm ad miutes of classroom time spet i Istat Recess. A separate evaluatio of Istat Recess i six elemetary schools i Los Ageles showed a icrease of 1,841 1,910 steps per school day, compared with studets who did ot have the physical activity breaks. 16 Followig a two-hour traiig sessio for teachers, a evaluatio of TAKE 10! was coducted i three classrooms i a suburba school i Georgia. Durig a five-day evaluatio the studets, from grades 1, 3, ad 5, spet a average of 86.1 miutes i TAKE 10! sessios, averagig 644 1,376 steps per 10-miute sessio. A evaluatio of Eergizers amog 243 studets from kidergarte through 4th grade used pedometers to measure daily steps durig the school day. Participatio i Eergizers raised physical activity levels by 782 steps per school day, compared to cotrol classrooms that did ot have similar physical activity breaks. The Happy 10 program was implemeted by teachers i grades 1 through 5 i Beijig, Chia. 11 Fourtee classrooms with 328 studets were i the itervetio school ad 12 classrooms with 425 studets were i the cotrol school. Questioaires were used to assess physical activity. Before ad after tests showed a sigificat icrease i hours per day spet i reported physical activity i itervetio schools (from 2.8 to 3.3 hours/day) ad a sigificat decrease i cotrol schools (from 4.4 to 2.9 hours/day). The differece betwee itervetio ad cotrol schools also was statistically sigificat, though the surprisigly large effects may be due to the selfreport measures. Thirty-five schools i Arizoa participated i a evaluatio of PLAY, comparig it with o treatmet, stadard physical educatio (PE) oly, ad PLAY plus PE. Compared to the cotrol group, the study showed a sigificat icrease i the steps take by childre who participated i the PLAY program oly (+1,418 steps); ad by those who participated i the PLAY plus PE program (+1,583). Girls experieced eve larger improvemets. Girls i the PLAY plus PE group took 2,277 more steps per day tha those i the cotrol group. A atioal program of the Robert Wood Johso Foudatio, with directio ad techical assistace provided by the Uiversity of Califoria, Sa Diego. activelivigresearch.org
Active Livig Research RESEARCH BRIEF February 2013 page 4 Oe evaluatio of PAAC foud that childre i schools implemetig the program were roughly 12 percet more physically active durig the school day tha those i schools that did ot take part i PAAC. The program also had a positive impact o weeked physical activity amog participatig studets: They were 17 percet more active tha peers i o-participatig schools. Studets were more physically active i classrooms with more physically active teachers. Providig short physical activity breaks durig the school day ca help improve o-task behavior I Texas I-CAN, o-task behavior was measured by direct observatio. Third grade classrooms compared time o-task before ad after studets participated i a active lesso ad a iactive lesso. Studets had small, but ot statistically sigificat, icreases i time o-task after a active lesso. However, there was a sigificat decrease i time o task after studets participated i a iactive lesso. The authors cocluded that participatio i active school lessos ca prevet declies i o-task behavior amog studets. The evaluatio of the Eergizers program described above showed a 20 percet improvemet i o-task behavior amog the least o-task studets. 10 Overall o-task behavior amog all studets improved by 8 percet. Istat Recess resulted i a sigificat, 11 percet icrease i the percetage of time studets devoted to o-task behavior. 15 Childre participatig i the PAAC evaluatio refereced above experieced greater improvemets i composite, readig, math, ad spellig scores compared to childre i cotrol schools. 13 A evaluatio of Makig the Grade with Diet ad Exercise foud that the umber of disciplie referrals was 58 percet lower followig the implemetatio of the program tha it was before the program. 17 Providig short physical activity breaks durig the school day improves some measures of health ABC for Fitess was studied over oe school year amog 1,216 studets i grades 2 through 4 i five schools i Missouri. 18 The program was evaluated usig objective data o studet aerobic capacity ad body compositio, as well as muscle stregth, edurace, ad flexibility. Studets i participatig schools had greater improvemets i stregth ad flexibility tha studets i cotrol schools. They also saw a 7 percet decrease i use of ADHD medicatio ad a 5 percet decrease i use of asthma medicatio. However, studets i cotrol schools had sigificatly smaller icreases i their body mass idices (BMIs) ad weights compared to studets i itervetio schools. No differeces betwee groups were observed for classroom behavior, academic performace, or attitudes toward physical activity. The Makig the Grade with Diet ad Exercise program showed a 67 percet declie i school urse visits. 17 A atioal program of the Robert Wood Johso Foudatio, with directio ad techical assistace provided by the Uiversity of Califoria, Sa Diego. activelivigresearch.org
Active Livig Research RESEARCH BRIEF February 2013 page 5 I the PAAC study, icreases i BMI over the three-year evaluatio period were sigificatly smaller i schools that coducted more tha 75 miutes of active lessos per week tha i schools that coducted less tha 75 miutes. 13 However, there were o differeces i other risk idicators such as cardiorespiratory fitess ad blood lipids. Providig short physical activity breaks durig the school day may ot improve all measures of physical activity or health outcomes While the PLAY curriculum icreased daily steps amog girls who participated i the program, PLAY did ot appear to be effective i boys. 12 Over three years i the PAAC study, studets who participated i activity breaks did ot have statistically differet BMIs tha those who did ot participate. 13 However, schools that coducted at least 75 miutes per week of activity breaks did slow dow excess weight gai amog studets. Providig short physical activity breaks durig the school day may compete with other school priorities ad be perceived egatively by teachers I the PAAC study, participatig teachers reported eedig more time to icorporate physical activity ito lesso plas ad eedig to develop more lessos appropriate for studets i 4th ad 5th grades because studets perceived breaks as too babyish. To coduct 90 miutes of active academic lessos per week, teachers said they eeded more lessos that could be taught withi a small classroom, ad wated a forum to share ideas o what lessos work well i the classroom. PE2GO traied teachers to provide PE lessos i their classrooms, targetig 4th ad 5th grade classrooms whose PE classes ad other physical activity opportuities had bee reduced or elimiated. 19 Whe asked about the barriers to implemetatio, teachers oted idoor space costraits, iadequate traiig, ad safety. Actio School! BC is a active school model that icluded, but was ot limited to, classroom activity breaks as a meas to icrease physical activity throughout the school day. 20 Negative commets about the program from teacher focus groups icluded competig curriculum demads, eedig more preparatio time, eedig a supportive school eviromet, ad lack of appropriate footwear ad clothig for childre. Negative commets from school facilitators icluded teacher overload, limited teacher time to familiarize themselves with the resources provided, lack of teacher belief i the priority of physical activity, lack of commuicatio amog teachers, ad limited space. A atioal program of the Robert Wood Johso Foudatio, with directio ad techical assistace provided by the Uiversity of Califoria, Sa Diego. activelivigresearch.org
Active Livig Research RESEARCH BRIEF February 2013 page 6 Coclusios ad Cosideratios Short physical activity breaks durig the school day may icrease physical activity, improve studet behavior ad o-task behavior, ad improve some measures of health. However, this brief is ot a exhaustive review of the literature. Several literature reviews have bee published that thoroughly ivestigate the associatio betwee physical activity breaks ad outcomes amog a variety of populatios, icludig childre, ad i a variety of settigs. Relevat reviews are listed at the ed of this brief. While classroom physical activity breaks have bee show to icrease physical activity, there is limited evidece to suggest that they ca impact other measures of health related to chroic disease (e.g., BMI, blood pressure, waist circumferece). It is possible that the level of physical activity achieved durig classroom activity breaks may ot be sufficiet to impact chroic disease risk factors amog childre. However, give the evidece suggestig that classroom activity breaks ca impact overall daily physical activity, classroom activity breaks may ecourage studets to be active o their ow outside of class, which could help studets meet the recommeded 60 miutes per day of moderate-to-vigorous physical activity. 21 I additio, give the recet evidece of the dagers of sedetary behavior, 22, 23 classroom activity breaks may provide a opportuity to reduce log bouts of sittig which could, i tur, reduce chroic disease risk. Classroom physical activity breaks ca help icrease physical activity amog childre durig the school day ad potetially complemet daily physical educatio programs (i.e., the PLAY program). I a era of tight budgets that may prevet schools from providig daily high-quality P.E., classroom physical activity breaks may act as a low-burde alterative. Classroom physical activity breaks ca be itegrated ito academic lessos, allowig teachers to teach academic cotet (e.g., math) through physical activity. Physically active lessos ca icrease, or prevet declies i, the amout of time studets sped o task, which may improve academic performace. A report from the Ceters for Disease Cotrol ad Prevetio summarizes research o the lik betwee physical educatio, physical activity, ad academic performace. 24 A brief from Active Livig Research also summarizes evidece o the lik betwee physical educatio, physical activity, ad academic performace. 25 Teachers may eed traiig to icorporate activity breaks ito existig classroom activities. Most programs described above provided just two to eight hours of traiig for teachers. Providig cotiuig educatio credit for teachers who participate i activity break traiig may be a strategy for icreasig teacher ethusiasm for the traiig. 15 It may be importat to ivolve teachers i the plaig, developmet ad/or selectio of classroom activity break materials ad procedures, i order to reduce potetial resistace to implemetatio of classroom activity breaks. A atioal program of the Robert Wood Johso Foudatio, with directio ad techical assistace provided by the Uiversity of Califoria, Sa Diego. activelivigresearch.org
Active Livig Research RESEARCH BRIEF February 2013 page 7 Uder-resourced schools that are at risk for cuttig fudig for PE may beefit most from classroom activity breaks. However, several studies oted idoor space costraits as a limitatio for implemetig classroom activity breaks. If uder-resourced schools are also less likely to have adequate classroom space i which to implemet activity breaks, this could pose a additioal barrier to implemetig activity breaks i classrooms. Limited data are available o the impact of classroom activity breaks amog middle school ad high school studets, which is whe the largest decreases i daily physical activity ad largest icreases i sedetary behavior ad BMI ted to occur. 5 Additioal research is eeded to uderstad methods for icorporatig classroom physical activity breaks amog older childre ad adolescets, or how to egage older studets i school day physical activity through differet types of programs. The PAAC study suggested that differet approaches for older studets may eed to begi as early as 4th or 5th grade. Additioal research is eeded to uderstad how to assist teachers with adaptig classroom activity break materials to make them most effective for childre with physical, cogitive, ad emotioal disabilities. Policy Implicatios Twelve states have school physical activity requiremets, which set stadards for how schools augmet PE to icrease physical activity levels. 26 Classroom physical activity breaks may help meet state requiremets for daily school-based physical activity. School officials ca support classroom physical activity breaks by icorporatig them ito daily physical activity requiremets outside physical educatio classes ad by eforcig local ad statewide madates for daily physical activity i school. Schools may eed to iclude laguage i dress code policies that supports implemetatio of classroom physical activity breaks by ecouragig studets to wear clothig coducive to physical activity durig the school day. A atioal program of the Robert Wood Johso Foudatio, with directio ad techical assistace provided by the Uiversity of Califoria, Sa Diego. activelivigresearch.org
Active Livig Research RESEARCH BRIEF February 2013 page 8 Relevat Literature Reviews Below are several literature reviews for those iterested i reviewig more research o physical activity breaks. Studies o physical activity breaks i classrooms that are icluded i the citatios below have bee icluded i this brief. Barr-Aderso, D.J., et al., Itegratio of short bouts of physical activity ito orgaizatioal routie a systematic review of the literature. Am J Prev Med, 2011. 40(1): p. 76-93. 27 Bartholomew, J.B. ad E.M. Jowers, Physically active academic lessos i elemetary childre. Prev Med, 2011. 52 Suppl 1: p. S51-4. 28 Ceters for Disease Cotrol ad Prevetio, The associatio betwee school based physical activity, icludig physical educatio, ad academic performace. 2010, U.S. Departmet of Health ad Huma Services: Atlata, GA. 24 Doelly, J.E. ad K. Lamboure, Classroom-based physical activity, cogitio, ad academic achievemet. Prev Med, 2011. 52 Suppl 1: p. S36-42. 29 Kibbe, D.L., et al., Te Years of TAKE 10! : Itegratig physical activity with academic cocepts i elemetary school classrooms. Prev Med, 2011. 52 Suppl 1: p. S43-50. 30 Mahar, M.T., Impact of short bouts of physical activity o attetio-to-task i elemetary school childre. Prev Med, 2011. 52 Suppl 1: p. S60-4. 31 Rasberry, C.N., et al., The associatio betwee school-based physical activity, icludig physical educatio, ad academic performace: a systematic review of the literature. Prev Med, 2011. 52 Suppl 1: p. S10-20. 32 This brief was prepared by Melicia C. Whitt-Glover, Ph.D., ad Amber T. Porter, BS, both of Gramercy Research Group, LLC, as well as Toi (Atroette) K. Yacey, MD, MPH of the UCLA School of Public Health. Ramie C. Alexader, Gramercy Research Group ad Virgiia Polytechic Istitute ad State Uiversity, Jeskell M. Creecy, Gramercy Research Group ad Wisto-Salem State Uiversity, ad Active Livig Research staff, cotributed as well. Peer review was provided by Joseph E. Doelly, Ed.D, Ceter for Physical Activity ad Weight Maagemet, Uiversity of Kasas; ad NiCole R. Keith, Ph.D., FACSM, Idiaa Uiversity-Purdue Uiversity, Idiaapolis. Disclosures Dr. Toi Yacey s compay Imhotep Publishig Ic. dba Istat Recess ows the Istat Recess trademark ad receives a licesig fee for the use of the trademark ad royalties o sales of Istat Recess materials. Royalties for Istat Recess DVDs ad CDs featurig professioal sports orgaizatios ad religious istitutios are doated to o-profits to promote the active livig missio. Dr. Yacey also receives a royalty from the Uiversity of Califoria Press o sales of her book Istat Recess: Buildig a Fit Natio 10 Miutes at a Time. Drs. Melicia C. Whitt-Glover ad Toi Yacey have received federal ad foudatio fudig to develop ad evaluate Istat Recess materials. For updates ad a Web-based versio of this brief, visit www.activelivigresearch.org. Active Livig Research, a atioal program of the Robert Wood Johso Foudatio, stimulates ad supports research to idetify evirometal factors ad policies that ifluece physical activity for childre ad families to iform effective childhood obesity prevetio strategies, particularly i low-icome ad racial/ethic commuities at highest risk. Active Livig Research wats solid research to be part of the public debate about active livig. Active Livig Research Uiversity of Califoria, Sa Diego 3900 Fifth Aveue, Suite 310 Sa Diego, CA 92103-3138 www.activelivigresearch.org A atioal program of the Robert Wood Johso Foudatio, with directio ad techical assistace provided by the Uiversity of Califoria, Sa Diego. activelivigresearch.org
Active Livig Research RESEARCH BRIEF February 2013 page 9 Edotes 1 CDC grad rouds: childhood obesity i the Uited States. MMWR Morb Mortal Wkly Rep, 2011. 60(2): p. 42 6. 2 Ogde, C.L., et al., Prevalece of high body mass idex i US childre ad adolescets, 2007 2008. JAMA, 2010. 303(3): p. 242 9. 3 Troiao, R.P., et al., Physical activity i the Uited States measured by accelerometer. Med Sci Sports Exerc, 2008. 40(1): p. 181-8. 4 Belcher, B.R., et al., Physical activity i US youth: effect of race/ethicity, age, geder, ad weight status. Med Sci Sports Exerc. 42(12): p. 2211 21. 5 Whitt-Glover, M.C., et al., Disparities i physical activity ad sedetary behaviors amog US childre ad adolescets: prevalece, correlates, ad itervetio implicatios. J Public Health Policy, 2009. 30 Suppl 1: p. S309 34. 6 Gortmaker, S.L., et al., Disparities i Youth Physical Activity i the Uited States: 2003 2006. Med Sci Sports Exerc. 7 Guihouya, B.C., et al., How school time physical activity is the big oe for daily activity amog schoolchildre: a semi-experimetal approach. J Phys Act Health, 2009. 6(4): p. 510 9. 8 Ward, D.S., School policies o physical educatio ad physical activity: A research sythesis., 2011, Active Livig Research, a Natioal Program of the Robert Wood Johso Foudatio: Pricto, NJ. 9 Stewart, J.A., et al., Exercise level ad eergy expediture i the TAKE 10! i-class physical activity program. J Sch Health, 2004. 74(10): p. 397-400. 10 Mahar, M.T., et al., Effects of a classroom-based program o physical activity ad o-task behavior. Med Sci Sports Exerc, 2006. 38(12): p. 2086 94. 11 Liu, A.L., et al., Report o childhood obesity i Chia (6) evaluatio of a classroom-based physical activity promotio program. Biomed Eviro Sci, 2007. 20(1): p. 19 23. 12 Pagrazi, R.P., et al., Impact of Promotig Lifestyle Activity for Youth (PLAY) o childre s physical activity. J Sch Health, 2003. 73(8): p. 317 21. 13 Doelly, J.E., et al., Physical Activity Across the Curriculum (PAAC): a radomized cotrolled trial to promote physical activity ad dimiish overweight ad obesity i elemetary school childre. Prev Med, 2009. 49(4): p. 336 41. 14 Grieco, L.A., E.M. Jowers, ad J.B. Bartholomew, Physically active academic lessos ad time o task: the moderatig effect of body mass idex. Med Sci Sports Exerc, 2009. 41(10): p. 1921 6. 15 Whitt-Glover, M.C., S.A. Ham, ad A.K. Yacey, Istat Recess: A Practical Tool for Icreasig Physical Activity Durig the School Day. Prog Commuity Health Partersh, 2011. 5(3): p. 289 97. 16 Woods, C.D., Evaluatio of Istat Recess exercise breaks as a meas for implemetig LAUSD physical activity policy i elemetary schools, 2011, Uiversity of Califoria Los Ageles. p. 76. 17 Sibley, B.A., et al., Makig the grade with diet ad exercise. AASA Joural of Scholarship ad Practice, 2008. 5(2): p. 38 45. 18 Katz, D.L., et al., Puttig physical activity where it fits i the school day: prelimiary results of the ABC (Activity Bursts i the Classroom) for fitess program. Prev Chroic Dis, 2010. 7(4): p. A82. 19 Marti, M.W., S. Marti, ad P. Rosegard, PE2GO: program evaluatio of a physical activity program i elemetary schools. J Phys Act Health, 2010. 7(5): p. 677 84. 20 Naylor, P.J., et al., Lessos leared from Actio Schools! BC a active school model to promote physical activity i elemetary schools. J Sci Med Sport, 2006. 9(5): p. 413 23. 21 U.S. Departmet of Health ad Huma Services, 2008 physical activity guidelies for Americas, 2008. 22 Tremblay, M.S., et al., Systematic review of sedetary behaviour ad health idicators i school-aged childre ad youth. It J Behav Nutr Phys Act, 2011. 8: p. 98. 23 Bakoski, A., et al., Sedetary activity associated with metabolic sydrome idepedet of physical activity. Diabetes Care, 2011. 34(2): p. 497 503. 24 Ceters for Disease Cotrol ad Prevetio, The associatio betwee school based physical activity, icludig physical educatio, ad academic performace, 2010, U.S. Departmet of Health ad Huma Services: Atlata, GA. 25 Active Livig Research, Physically active ad fit childre perform better i school fact sheet, 2012: Priceto, NJ. 26 Trust for America s Health ad The Robert Wood Johso Foudatio, F as i Fat: How obesity threates America s future, 2012, T.f.A.s. Health, Editor 2012: Washigto, DC. 27 Barr-Aderso, D.J., et al., Itegratio of short bouts of physical activity ito orgaizatioal routie a systematic review of the literature. Am J Prev Med, 2011. 40(1): p. 76 93. 28 Bartholomew, J.B. ad E.M. Jowers, Physically active academic lessos i elemetary childre. Prev Med, 2011. 52 Suppl 1: p. S51 4. 29 Doelly, J.E. ad K. Lamboure, Classroom-based physical activity, cogitio, ad academic achievemet. Prev Med, 2011. 52 Suppl 1: p. S36 42. 30 Kibbe, D.L., et al., Te Years of TAKE 10! : Itegratig physical activity with academic cocepts i elemetary school classrooms. Prev Med, 2011. 52 Suppl 1: p. S43 50. 31 Mahar, M.T., Impact of short bouts of physical activity o attetio-to-task i elemetary school childre. Prev Med, 2011. 52 Suppl 1: p. S60 4. 32 Rasberry, C.N., et al., The associatio betwee school-based physical activity, icludig physical educatio, ad academic performace: a systematic review of the literature. Prev Med, 2011. 52 Suppl 1: p. S10 20. A atioal program of the Robert Wood Johso Foudatio, with directio ad techical assistace provided by the Uiversity of Califoria, Sa Diego. activelivigresearch.org