- High level of cardiorespiratory fitness was associated with reduction in the risk for colorectal cancer.
- The reduction in risk was more evident in men than women, although the sex difference was not statistically significant.
Why this matters
- Findings indicate that achieving a high level of fitness by individuals who are currently unfit represents a significant individual-level and public health opportunity to lower the risk for colorectal cancer.
- Prospective analysis of cardiorespiratory fitness in relation to colorectal cancer in 59,191 UK Biobank participants (aged 39-70 years) without prevalent cancer.
- Cardiorespiratory fitness was defined as physical work capacity at 75% of the maximum heart rate, standardised to body mass (PWC75%).
- Funding: UK Biobank was supported by the Wellcome Trust and others.
- 232 cases of colorectal cancer (151 colon cancers; 79 rectal cancers) were reported during a mean follow-up of 4.6 years.
- The adjusted HR of colorectal cancer per interquartile increase in cardiorespiratory fitness was 0.78 (95% CI, 0.62-0.97).
- This inverse association was more pronounced for colon cancer (HR, 0.74; 95% CI, 0.56-0.97) and was weakest for rectal cancer (HR, 0.88; 95% CI, 0.62-1.26).
- Cardiorespiratory fitness showed an inverse association with colorectal cancer in men (HR, 0.72; 95% CI, 0.55-0.94) but not in women (HR, 0.99; 95% CI, 0.71-1.38), although the interaction by sex was not statistically significant (P=.192).
- Relatively short follow-up period; limited number of cases, especially in the subsite analyses.