Sedentary lifestyles, characterized by prolonged sitting or reclining with low energy expenditure, are associated with an increased risk of developing cancer and dying from the disease, according to new research.
The study, published in the journal PLOS Medicine, analyzed data from over 91,000 adults who wore wrist trackers to monitor their physical activity and sedentary time. Participants were followed for a median of over 12 years to track cancer diagnoses and cancer-related deaths.
Researchers found that individuals who incorporated movement or exercise to break up their sedentary periods had a lower likelihood of cancer-related death. Specifically, replacing sedentary time with physical activity showed significant risk reductions.
An hour or more of light-intensity physical activity, such as slow walking or household chores, was linked to a 12% reduced risk of cancer-related death. Replacing 30 minutes of sitting with moderate-intensity activity, like a brisk walk, reduced cancer-related death risk by 8%. Even replacing just five minutes of sedentary time with vigorous exercise led to a 22% lower rate of cancer-related death.
“Just get up. That is the main message there,” said Dr. Heidi Prather, founder and medical director of the Hospital for Special Surgery’s Lifestyle Medicine Program, who was not affiliated with the research. “Obviously, we’re all tied to a computer or a car or something that keeps us inactive, but just interrupting that with any type of activity seems to have, per their data, some very impressive results. Not just cancer death, but even risk of developing cancer.”
The study defined prolonged sedentary behavior as sitting for more than 30 minutes continuously, while interrupted sedentary behavior involved periods of sitting lasting less than 30 minutes, broken up by movement. Those with higher rates of prolonged sedentary behavior faced a greater risk of certain cancers, including breast, colorectal, esophageal, thyroid, and liver cancers, as well as a higher risk of death from cancer.
Movement helps reduce inflammation in the body, which is a known factor in cancer development. While genetics play a role in cancer risk, lifestyle factors such as diet, sleep, stress, and exercise contribute significantly. Sedentary behavior can also contribute to obesity, itself a risk factor for several types of cancer.
Experts emphasize that incorporating any amount of movement is beneficial, even for those who engage in regular exercise. Simple actions like parking further away from a destination, taking the stairs, or getting off public transport a stop early can help counter the negative effects of prolonged sitting.
“It doesn’t have to be that restrictive,” Prather explained. “Setting small goals will get you to the bigger goal, and start easy, start with something you wouldn’t even make a goal, make it so easy.”
Even individuals with established exercise routines are advised to break up long periods of sitting with short walks or standing breaks throughout the day to maintain blood flow and muscle activity. The research suggests that prolonged sedentary behavior can be as detrimental to health as not exercising at all.