Increased cardiorespiratory fitness is related to decreased risk of major chronic illnesses, including cardiovascular disease, type 2 diabetes, and cancer, but its association with colorectal cancer specifically has received very little attention. We examined the relation of cardiorespiratory fitness to colorectal cancer in 59,191 UK Biobank participants aged 39–70 years without prevalent cancer at baseline, followed from 2009 to 2014. Submaximal bicycle ergometry was conducted at study entry, and cardiorespiratory fitness was defined as physical work capacity at 75% of the maximum heart rate, standardised to body mass (PWC_75%). Multivariable Cox proportional hazards regression was performed to obtain hazard ratios (HR) and corresponding 95% confidence intervals (CI). During a mean follow-up of 4.6 years, 232 participants developed colorectal cancer (151 colon cancers; 79 rectal cancers). When comparing the 75th to the 25th percentiles of PWC_75%, the multivariable-adjusted HR of colorectal cancer was 0.78 (95% CI 0.62–0.97). That relation was largely driven by an inverse association with colon cancer (HR 0.74, 95% CI 0.56–0.97) and less so with rectal cancer (HR 0.88, 95% CI 0.62–1.26; p value for difference by colorectal cancer endpoint = 0.056). The inverse relation of cardiorespiratory fitness with colorectal cancer was more evident in men (HR 0.72, 95% CI 0.55–0.94) than women (HR 0.99, 95% CI 0.71–1.38), although the gender difference was not statistically significant (p value for interaction = 0.192). Increased cardiorespiratory fitness is associated with decreased risk of colorectal cancer. Potential heterogeneity by colorectal cancer anatomic subsite and gender requires further study.

心肺适应性的提高与主要慢性病（包括心血管疾病，2型糖尿病和癌症）的风险降低相关，但与大肠癌的关系尤其受到关注。我们在2009年至2014年研究了59,191位年龄在39-70岁且未患癌症的英国Biobank参与者中的心肺适应性与大肠癌之间的关系，并于2009年至2014年进行了研究。在研究开始时进行了次最大的自行车测功，心肺适应性被定义为身体的工作能力以最大心率的75％进行标准化，以体重计（PWC _75％）。进行多变量Cox比例风险回归以获得风险比（HR）和相应的95％置信区间（CI）。在平均4.6年的随访期间，有232名参与者罹患了大肠癌（151例结肠癌； 79例直肠癌）。比较_75％到25％的PWC _75％时，大肠癌的多变量调整后HR为0.78（95％CI 0.62-0.97）。这种关系很大程度上是由于与结肠癌呈负相关（HR 0.74，95％CI 0.56-0.97），与直肠癌呈负相关（HR 0.88，95％CI 0.62-1.26；p结直肠癌终点的差异值= 0.056）。尽管性别差异在统计学上无统计学意义（p值），但男性（HR 0.72，95％CI 0.55–0.94）比女性（HR 0.99，95％CI 0.71–1.38）更明显地反映了心肺健康与大肠癌的逆向关系。互动= 0.192）。心肺适应性的提高与结直肠癌风险的降低相关。大肠癌解剖亚位和性别的潜在异质性需要进一步研究。