title: Leisure time physical activity of moderate to vigorous intensity and mortality: a large pooled cohort analysis.
abstract: BACKGROUND
  Leisure time physical activity reduces the risk of premature mortality, but the years of life expectancy gained at different levels remains unclear. Our objective was to determine the years of life gained after age 40 associated with various levels of physical activity, both overall and according to body mass index (BMI) groups, in a large pooled analysis.
  
  
  RESULTS
  We examined the association of leisure time physical activity with mortality during follow-up in pooled data from six prospective cohort studies in the National Cancer Institute Cohort Consortium, comprising 654,827 individuals, 21-90 y of age. Physical activity was categorized by metabolic equivalent hours per week (MET-h/wk). Life expectancies and years of life gained/lost were calculated using direct adjusted survival curves (for participants 40+ years of age), with 95% confidence intervals (CIs) derived by bootstrap. The study includes a median 10 y of follow-up and 82,465 deaths. A physical activity level of 0.1-3.74 MET-h/wk, equivalent to brisk walking for up to 75 min/wk, was associated with a gain of 1.8 (95% CI: 1.6-2.0) y in life expectancy relative to no leisure time activity (0 MET-h/wk). Higher levels of physical activity were associated with greater gains in life expectancy, with a gain of 4.5 (95% CI: 4.3-4.7) y at the highest level (22.5+ MET-h/wk, equivalent to brisk walking for 450+ min/wk). Substantial gains were also observed in each BMI group. In joint analyses, being active (7.5+ MET-h/wk) and normal weight (BMI 18.5-24.9) was associated with a gain of 7.2 (95% CI: 6.5-7.9) y of life compared to being inactive (0 MET-h/wk) and obese (BMI 35.0+). A limitation was that physical activity and BMI were ascertained by self report.
  
  
  CONCLUSIONS
  More leisure time physical activity was associated with longer life expectancy across a range of activity levels and BMI groups. Please see later in the article for the Editors' Summary.
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, USA. moorest@mail.nih.gov
authors.forename: Steven C
authors.initials: SC
authors.lastname: Moore
authors.forename: Alpa V
authors.initials: AV
authors.lastname: Patel
authors.forename: Charles E
authors.initials: CE
authors.lastname: Matthews
authors.forename: Amy
authors.initials: A
authors.lastname: Berrington de Gonzalez
authors.forename: Yikyung
authors.initials: Y
authors.lastname: Park
authors.forename: Hormuzd A
authors.initials: HA
authors.lastname: Katki
authors.forename: Martha S
authors.initials: MS
authors.lastname: Linet
authors.forename: Elisabete
authors.initials: E
authors.lastname: Weiderpass
authors.forename: Kala
authors.initials: K
authors.lastname: Visvanathan
authors.forename: Kathy J
authors.initials: KJ
authors.lastname: Helzlsouer
authors.forename: Michael
authors.initials: M
authors.lastname: Thun
authors.forename: Susan M
authors.initials: SM
authors.lastname: Gapstur
authors.forename: Patricia
authors.initials: P
authors.lastname: Hartge
authors.forename: I-Min
authors.initials: IM
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007899:Leisure Activities; D008017:Life Expectancy; D008297:Male; D055686:Metabolic Equivalent; D008875:Middle Aged; D009026:Mortality; D009043:Motor Activity; D009765:Obesity / Q000453:epidemiology; D011446:Prospective Studies; D018570:Risk Assessment; D057566:Self Report; D011795:Surveys and Questionnaires; D014481:United States / Q000453:epidemiology; D055815:Young Adult