UK — A study led by the University of Glasgow and published in Plos Medicine found an association between prolonged sedentary behavior and an increased risk of cancer death. The study also indicated that incorporating physical activity into periods of inactivity could reduce this risk.

The research analyzed data from wearable devices worn by more than 91,000 participants in the UK Biobank, who were followed for an average of 12 years. Sitting or lying down while awake for over 30 minutes in one period each day was linked to a higher risk of cancer death. Additionally, each extra hour of prolonged inactivity daily was associated with a 10% increase in the risk of cancer death.

Breaking up sedentary periods longer than 30 minutes with bursts of physical activity was associated with a decreased risk of cancer death. Replacing one hour of daily sedentary behavior with light physical activity, such as ironing or washing up, was associated with a 12% lower risk. Substituting 30 minutes of daily inactivity with 30 minutes of moderate physical activity, like walking at an average pace, was associated with an 8% lower risk of cancer death. Replacing five minutes of inactivity each day with five minutes of vigorous physical activity was associated with a 22% lower risk.

Dr. Frederick Ho, the lead author of the study at the University of Glasgow, said: "What our data shows is that sitting for more than 30 minutes at a time is particularly linked to a higher risk of cancer. The good news is that breaking up your sitting time with something as simple as a short walk could be protective. Current health guidelines focus heavily on moderate or vigorous exercise, but our findings show that light movement should not be ignored. Moving forward, clinical trials will help us move beyond blanket advice and develop personalised strategies for breaking up sitting time."

The researchers conducted a statistical analysis of an observational study, which means they could not establish causation. Prof. Kevin McConway, an emeritus professor of applied statistics at the Open University, stated that the findings were interesting but further research would be needed.