Researchers at the University of Gothenburg have uncovered a clear association between high cardiorespiratory endurance in men and a lower likelihood of nine distinct cancer types. The study, detailed in a respected medical journal, adds a new dimension to how physical fitness relates to cancer risk and invites a broader look at how endurance capacity translates into real health outcomes over time.
Cardiorespiratory endurance measures how long a person can sustain aerobic activities such as running, cycling, climbing stairs, or swimming. In this investigation, scientists drew on health data from Swedes who were recruited between 1968 and 2005. By the time the researchers conducted their final analysis in 2019, data on 18 cancer types were available, and the pool included more than a million men. The scale of this work helps reduce sampling bias and strengthens the reliability of the observed associations across a large population group.
Among younger recruits aged 16 to 25, those with lower fitness levels tended to show higher rates of obesity and greater likelihood of engaging in risky behaviors related to alcohol and substance use. They also more often had parents with lower educational attainment, suggesting that early life conditions can shape both physical fitness and long-term health trajectories. This broader context reinforces the idea that endurance is part of a pattern of health habits and environmental factors that influence disease risk over the life course.
Concerning cancer risk, the findings showed that men with high stamina were notably less likely to develop several cancers. Specifically, the odds of developing lung cancer were 42% lower, liver cancer 40% lower, and esophageal cancer 39% lower among those with greater endurance. Stomach cancer risk also declined by about 21% in this group. These reductions remained meaningful after accounting for a variety of potential confounders commonly linked to cancer development, underscoring a robust health signal associated with aerobic capacity.
Additionally, the study observed a 5% reduction in colorectal cancer risk and a 12% lower risk of pancreatic cancer among men with higher endurance. There were also sizable declines—ranging from 18% to 20%—in the incidence of colorectal, kidney, and head and neck cancers, respectively. Taken together, these results suggest that stronger cardiovascular and respiratory fitness may be tied to a broad attenuation of cancer risk across several organ systems, possibly reflecting improved metabolism, reduced inflammation, and enhanced immune surveillance that accompany frequent aerobic activity.
However, the analysis revealed a paradoxical increase in risk for two cancer types: prostate cancer rose by 7% and skin cancer by 31% among those with higher cardiorespiratory endurance. The researchers offered a plausible explanation: individuals with higher fitness levels may undergo more intensive health screening and preventive care, leading to greater detection rates for these particular cancers. This possibility highlights the importance of considering screening practices when interpreting associations between fitness and cancer incidence.
As with many observational studies, the authors cautioned that the work cannot establish cause and effect. The observed relationships reflect correlations that warrant further investigation to understand the biological mechanisms at play and the potential role of lifestyle factors that coincide with endurance training. In practice, the takeaway is that higher cardiorespiratory fitness appears linked to a lower overall cancer burden in this cohort, but it does not prove that improving endurance will directly prevent cancer on an individual level. The research adds to a growing body of evidence supporting regular aerobic exercise as a cornerstone of general health and cancer risk reduction, while also reminding clinicians and individuals to consider a full spectrum of screening and risk assessment in their preventive strategies.