title: Cardiorespiratory fitness and death from cancer: a 42-year follow-up from the Copenhagen Male Study.
abstract: OBJECTIVE
  Poor cardiorespiratory fitness (CRF) is associated with death from cancer. If follow-up time is short, this association may be confounded by subclinical disease already present at the time of CRF assessment. This study investigates the association between CRF and death from cancer and any cause with 42 years and 44 years of follow-up, respectively.
  Middle-aged, employed and cancer-free Danish men from the prospectiveCopenhagen Male Study, enrolled in 1970-1971, were included. CRF (maximal oxygen consumption (VO2max)) was estimated using a bicycle ergometer test and analysed in multivariable Cox models including conventional risk factors, social class and self-reported physical activity. Death from cancer and all-cause mortality was assessed using Danish national registers. Follow-up was 100% complete.
  
  
  RESULTS
  In total, 5131 men were included, mean (SD) age 48.8 (5.4) years. During 44 years of follow-up, 4486 subjects died (87.4%), 1527 (29.8%) from cancer. In multivariable models, CRF was highly significantly inversely associated with death from cancer and all-cause mortality ((HR (95% CI)) 0.83 (0.77 to 0.90) and 0.89 (0.85 to 0.93) per 10 mL/kg/min increase in estimated VO2max, respectively). A similar association was seen across specific cancer groups, except death from prostate cancer (1.00 (0.82 to 1.2); p=0.97; n=231). The associations between CRF and outcomes remained essentially unchanged after excluding subjects dying within 10 years (n=377) and 20 years (n=1276) of inclusion.
  
  
  CONCLUSIONS
  CRF is highly significantly inversely associated with death from cancer and all-cause mortality. The associations are robust for exclusion of subjects dying within 20 years of study inclusion, thereby suggesting a minimal influence of reverse causation.
authors.affiliation: Department of Internal Medicine, Holbaek Hospital, Holbæk, Denmark.
authors.forename: Magnus Thorsten
authors.initials: MT
authors.lastname: Jensen
authors.affiliation: National Research Centre for the Working Environment, Copenhagen, Denmark.
authors.forename: Andreas
authors.initials: A
authors.lastname: Holtermann
authors.affiliation: National Research Centre for the Working Environment, Copenhagen, Denmark.|Epidemiological Research Unit, Departments of Occupational and Environmental Medicine, The Copenhagen Male Study, Bispebjerg University Hospital, Copenhagen, Denmark.
authors.forename: Hans
authors.initials: H
authors.lastname: Bay
authors.affiliation: National Research Centre for the Working Environment, Copenhagen, Denmark.|Epidemiological Research Unit, Departments of Occupational and Environmental Medicine, The Copenhagen Male Study, Bispebjerg University Hospital, Copenhagen, Denmark.
authors.forename: Finn
authors.initials: F
authors.lastname: Gyntelberg
mesh_terms: D000328:Adult; D000072599:Cardiorespiratory Fitness; D003718:Denmark; D015444:Exercise; D005080:Exercise Test; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009026:Mortality; D009369:Neoplasms / Q000401:mortality*; D010101:Oxygen Consumption; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors
keywords: Cancer; Fitness; Longevity; Physical fitness; VO2max