Elsevier

Preventive Medicine

Volume 55, Issue 5, November 2012, Pages 458-463
Preventive Medicine

Relationship between physical activity and general mental health

https://doi.org/10.1016/j.ypmed.2012.08.021Get rights and content

Abstract

Purpose

We investigated the relationship between physical activity and mental health and determined the optimal amount of physical activity associated with better mental health.

Method

Self-reported data from a national random sample of 7674 adult respondents collected during the 2008 U.S. Health Information National Trends 2007 Survey (HINTS) were analyzed in 2012. Mental health was plotted against the number of hours of physical activity per week using a fractional 2-degree polynomial function. Demographic and physical health factors related to poorer mental health were examined. The optimal range of physical activity associated with poorer mental health was examined by age, gender, and physical health.

Results

A curvilinear association was observed between physical activity and general mental health. The optimal threshold volume for mental health benefits was of 2.5 to 7.5 h of weekly physical activity. The associations varied by gender, age, and physical health status. Individuals who engaged in the optimal amount of physical activity were more likely to have reported better mental health (odds ratio = 1.39, p = 0.006).

Conclusions

This study established a hyperbolic dose–response relationship between physical activity and general mental health, with an optimal range of 2.5 to 7.5 h of physical activity per week.

Highlights

► General mental health was modeled against weekly hours of physical activity. ► The physical activity threshold for better mental health was 2.5–7.5 weekly hours. ► Higher and lower physical activity was associated with poorer mental health.

Introduction

Mental health disorders rank among the five conditions with the highest direct medical expenditures in the United States (The Agency for Healthcare Research and Quality, 2009). Mental health problems can impair physical health and social and occupational functioning (Bhui and Fletcher, 2000, Korniloff et al., 2012, Murray and Lopez, 1997, Wells et al., 1989). Thus, the development of preventive strategies has been advocated (McLaughlin, 2011).

Physical activity is an effective prevention measure because it improves health (Garber et al., 2011, U.S. Department of Health and Human Services, 2008b). Apart from the considerable physical health-related benefits, a number of psychological benefits have been identified, with the most evidence about depression and anxiety (Abu-Omar et al., 2004, Dinas et al., 2011, Dunn et al., 2001, Dunn et al., 2005, Garber et al., 2011, Motl et al., 2004, Park et al., 2011, Sieverdes et al., 2011, Strohle, 2009, U.S. Department of Health and Human Services, 2008b, Wyshak, 2001). For example, physical activity can reduce depressive symptoms in individuals diagnosed with major depression, in healthy adults, and in medical patients with diabetes and cancer survivors (U.S. Department of Health and Human Services, 2008b). Regular physical activity appears to be protective against anxiety disorders (Carek et al., 2011, Strohle, 2009, U.S. Department of Health and Human Services, 2008b).

The optimal dose of physical activity needed to improve or sustain mental health is unknown (Carek et al., 2011, U.S. Department of Health and Human Services, 2008b). A dose–response relationship between physical activity levels and physical health outcomes is well-accepted, although the exact shape of the dose–response curve is not well understood (Garber et al., 2011, Haskell et al., 2007, U.S. Department of Health and Human Services, 2008b). Whether there is a dose–response relationship between physical activity and mental health is unclear; the shape of the association is unknown (Abu-Omar et al., 2004, Dunn et al., 2001, Dunn et al., 2005, Garber et al., 2011).

Psychological distress is a term that refers to the emotional state, somatic symptoms, discomforts, and impaired coping associated with mental and physical health disorders (Ridner, 2004) and is an indicator of general mental health (Kessler et al., 2002). The aim of this study was to investigate the dose–response relationship between physical activity and general mental health, to identify the optimal range of physical activity associated with better mental health, and to determine whether the association between physical activity and general mental health differs according to selected demographic characteristics and health.

Section snippets

Materials and methods

This observational cross-sectional study used publically available data from the 2008 administration of the U.S. Health Information National Trends 2007 Survey (HINTS), analyzed in 2012 (Cantor et al., 2009, National Cancer Institute, 2011). Self-reported data were randomly collected by computer-assisted telephone interview by mail following a strict survey protocol (Cantor et al., 2009). The Teachers College, Columbia University Institutional Review Board determined that this study was exempt

Results

There were 7674 adult respondents, representing 213,621,995 individuals. The mean unstandardized mental health score was 4.233 (95% confidence interval [CI]: 4.226, 4.240), and ~ 30% had poorer mental health. Table 1 shows the percentage of respondents by categories of mental health and physical activity per week. The weighted proportion of adults with poorer mental health was significantly different than those with better mental health by physical activity categories (χ2 = 91.3, p < 0.001).

Discussion

This study demonstrates a curvilinear association between optimal levels of physical activity and mental health, while previous studies have shown linear trends (Abu-Omar et al., 2004, Bhui and Fletcher, 2000, Dunn et al., 2005, Paffenbarger et al., 1994, Sieverdes et al., 2011). This is probably accountable to the larger and more representative national sample, continuous measures, and a statistical analytic methodology allowing for detection of the curvilinear associations. An optimal range

Study limitations and strengths

This cross-sectional study shows associations, but causality cannot be inferred. Equally plausible explanations for these findings exist: a physically active lifestyle may improve mental health, while having a mental health disorder may increase sedentary activity or result in excessive exercise behavior. The scale used to measure mental health can only screen for–not diagnose–mental health disorders. Respondents may have over- or under-estimated their overall physical activity. The separate

Conclusions

These findings show that there is a dose response relationship between physical activity and better mental health. In addition, lower and higher thresholds of physical activity are associated with poorer mental health. These findings provide support for the notion that regular activity may lead to prevention of mental health disorders, but these findings need to be confirmed by randomized control trials.

Conflict of interest statement

The authors have no conflicts of interest to declare. There was no funding source for this study.

References (63)

  • D. Bamber et al.

    “It's exercise or nothing”: a qualitative analysis of exercise dependence

    Br. J. Sports Med.

    (2000)
  • A.J. Baxter et al.

    Global prevalence of anxiety disorders: a systematic review and meta-regression

    Psychol. Med.

    (2012)
  • K. Berczik et al.

    Exercise addiction: symptoms, diagnosis, epidemiology, and etiology

    Subst. Use Misuse

    (2012)
  • K. Bhui et al.

    Common mood and anxiety states: gender differences in the protective effect of physical activity

    Soc. Psychiatry Psychiatr. Epidemiol.

    (2000)
  • D. Blazer et al.

    The association of age and depression among the elderly: an epidemiologic exploration

    J. Gerontol.

    (1991)
  • D. Cantor et al.

    Health Information National Trends Survey (HINTS) 2007 Final Report

    (2009)
  • P.J. Carek et al.

    Exercise for the treatment of depression and anxiety

    Int. J. Psychiatry Med.

    (2011)
  • W.G. Cochran

    Sampling Techniques

    (1997)
  • V.C. Delisle et al.

    Revisiting gender differences in somatic symptoms of depression: much ado about nothing?

    PLoS One

    (2012)
  • P.C. Dinas et al.

    Effects of exercise and physical activity on depression

    Ir. J. Med. Sci.

    (2011)
  • Division of Health Interview Statistics National Center for Health Statistics

    2007 National Health Interview Survey (NHIS) Public Use Data Release

    (2007)
  • A.L. Dunn et al.

    Physical activity dose–response effects on outcomes of depression and anxiety

    Med. Sci. Sports Exerc.

    (2001)
  • T.A. Furukawa et al.

    The performance of the K6 and K10 screening scales for psychological distress in the Australian National Survey of Mental Health and Well-Being

    Psychol. Med.

    (2003)
  • C.E. Garber et al.

    Quantity and quality of exercise for developing and maintaining cardiorespiratory, musculoskeletal, and neuromotor fitness in apparently healthy adults: guidance for prescribing exercise

    Med. Sci. Sports Exerc.

    (2011)
  • P.E. Greenberg et al.

    The economic burden of anxiety disorders in the 1990s

    J. Clin. Psychiatry

    (1999)
  • D.A. Groffen et al.

    Unhealthy lifestyles do not mediate the relationship between socioeconomic status and incident depressive symptoms: the health ABC study

    Am. J. Geriatr. Psychiatry

    (2012)
  • W.L. Haskell et al.

    Physical activity and public health: updated recommendation for adults from the American College of Sports Medicine and the American Heart Association

    Med. Sci. Sports Exerc.

    (2007)
  • T. Kawada et al.

    Depressive state and subsequent weight gain in workers: a 4-year follow-up study

    Work

    (2011)
  • R.C. Kessler et al.

    Short screening scales to monitor population prevalences and trends in non-specific psychological distress

    Psychol. Med.

    (2002)
  • R.C. Kessler et al.

    Screening for serious mental illness in the general population

    Arch. Gen. Psychiatry

    (2003)
  • R.C. Kessler et al.

    Lifetime prevalence and age-of-onset distributions of DSM-IV disorders in the National Comorbidity Survey Replication

    Arch. Gen. Psychiatry

    (2005)
  • Cited by (0)

    1

    Permanent Address: Department of Physical Education and the Health and Exercise Science Laboratory, Institute of Sports Science, Seoul National University, Seoul, Republic of Korea.

    2

    Present Address: Department of Medical Education at the College of Medicine, University of Illinois at Chicago, Chicago, IL, United States.

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