In a large-scale prospective cohort study involving over 85,000 adults in the United Kingdom, researchers from the National Institutes of Health (NIH) and the University of Oxford found that individuals who engaged in daily physical activity—whether of light or moderate-to-vigorous intensity—faced a lower risk of developing cancer compared to those who led more sedentary lifestyles. The study’s findings, published on 26 March 2025 in the British Journal of Sports Medicine, are among the first to examine the protective effects of light-intensity activity, such as household chores and routine errands, on cancer risk.
While previous research has consistently demonstrated an inverse relationship between physical activity and cancer incidence, most earlier studies have relied on self-reported questionnaires. Such tools are prone to inaccuracies, particularly in capturing the intensity and duration of various physical activities. Moreover, investigations that employed objective measures typically focused on higher-intensity exercise, leaving a gap in understanding regarding the role of lower-intensity movements in disease prevention.
In the current study, led by scientists at the NIH’s National Cancer Institute, participants in the UK Biobank study—whose median age was 63—wore wrist-worn accelerometers continuously for one week. These devices precisely measured total daily activity, intensity, and step count. Researchers then analysed the relationship between these physical activity patterns and the incidence of 13 types of cancer previously linked to exercise, including breast and colorectal cancer.
Over an average follow-up period of 5.8 years, 2,633 participants were diagnosed with one of the 13 targeted cancer types. The data revealed that individuals in the highest quartile of daily physical activity had a 26% lower risk of developing cancer compared to those in the lowest activity group. Furthermore, when researchers modelled the effect of substituting sedentary time with either light-intensity or moderate-to-vigorous activity, they observed a notable reduction in cancer risk. These associations remained statistically significant even after adjusting for various potential confounding factors, including demographic characteristics, lifestyle habits, body mass index (BMI), and pre-existing health conditions.
The study also examined the specific impact of step count on cancer risk, independent of step intensity. Interestingly, while faster walking did not offer additional benefits, higher daily step counts were consistently associated with reduced cancer risk. Compared to individuals averaging 5,000 steps daily, those who walked 7,000 steps daily experienced an 11% lower risk, and those reaching 9,000 steps saw a 16% reduction. However, the benefit appeared to plateau beyond the 9,000-step mark.
Taken together, these findings suggest that even modest increases in daily movement—particularly among relatively inactive individuals—may contribute meaningfully to cancer prevention. The authors highlighted that encouraging more walking and routine low-intensity activity, regardless of pace, could be an accessible and effective strategy to help lower cancer risk across the population.
More information: Alaina Shreves et al, Amount and intensity of daily total physical activity, step count and risk of incident cancer in the UK Biobank, British Journal of Sports Medicine. DOI: 0.1136/bjsports-2024-109360
Journal information: British Journal of Sports Medicine Provided by NIH/National Cancer Institute
