Sitting for more than 30 minutes at a time linked to higher risk of cancer death
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- University of Glasgow researchers tracked more than 91,000 UK Biobank participants for an average of 12 years and found that prolonged inactivity lasting more than 30 minutes at a time was associated with higher cancer death risk
- Each additional hour of continuous sedentary behavior per day was associated with a 10% increase in cancer death risk, according to the study published in Plos Medicine
- Replacing one hour of daily sedentary time with light physical activity such as ironing or washing up was associated with a 12% lower risk of cancer death
- Substituting 30 minutes of inactivity with 30 minutes of moderate activity like average-pace walking was associated with an 8% lower cancer death risk
- Replacing just five minutes of inactivity with five minutes of vigorous physical activity each day was associated with a 22% lower cancer death risk
- Lead author Dr. Frederick Ho said even short walks could be protective and that light movement should not be ignored by current exercise guidelines
- Prof Kevin McConway of the Open University, who was not involved in the research, called the findings interesting but noted further research was needed; the study was observational and cannot prove causation
Why it matters: The study challenges the standard prescription to hit moderate or vigorous exercise targets by showing that even mundane light activity — housework, washing up — substituted for sitting cut cancer death risk by 12%, more than moderate walking's 8% reduction per 30 minutes, suggesting that how sedentary time is accumulated matters as much as total exercise.
