Reducing vigorous exercise by just a few minutes each day could increase cancer risk by as much as 15 percent, a study suggests. Researchers from University College London warn that maintaining activity levels throughout life is crucial, as even minor decreases in physical exertion can negatively impact health.
The study, published in the journal BMC Medicine, analyzed lifestyle data from 59,218 individuals in the UK Biobank, with an average age of 61.7. Over an eight-year follow-up period, 2,385 cancer cases were recorded within the group. The research team assessed the amount of time participants spent sleeping, engaged in sedentary behaviors like watching television, standing, and performing any form of movement, noting the intensity of these activities.
Findings indicated a correlation between increased movement and a lower cancer risk. Specifically, substituting 15 minutes of sleep or sedentary time with 15 minutes of physical activity was associated with a 2 percent reduced risk of cancer. Conversely, replacing 30 minutes of movement, regardless of intensity, with 30 minutes of sedentary behavior increased cancer risk by 8 percent.
Dr. John Mitchell, the study's lead author, highlighted that individuals who spend a significant amount of time sitting are at a higher risk of cancer. The research also explored the potential consequences for active individuals who reduce their activity levels, finding that they too face an elevated cancer risk.
"Our study showed losing two to three minutes per day of vigorous activity and replacing it with sitting down, sleep or light activity increased their cancer risk," Dr. Mitchell stated. He defined vigorous activity as anything that elevates heart rate and causes sweating, such as sports, rushing up stairs, or carrying heavy groceries. The primary message for those already leading active lives is the importance of sustaining that activity level as they age.
Previous research has established a link between higher physical activity levels and a reduced risk of several cancers, including bladder, breast, and bowel cancers. Current NHS guidelines recommend that adults aim for at least 150 minutes of moderate activity or 75 minutes of vigorous activity per week.