The More One Sits, The Older One Looks? Study Sheds Light - Video

Between long commutes, Zoom-packed workdays and evenings of streaming and scrolling, millennials now spend more than 60 hours per week sitting, potentially boosting their heart disease risk and accelerating other signs of aging, according to new CU Boulder and University of California Riverside research. The findings were published in PLOS ONE.

The study of more than 1,000 former or current Colorado residents, including 730 twins, is among the first to explore how prolonged sitting impacts health measures such as cholesterol and body mass index (BMI) in young adults.

It found that meeting the minimum recommended physical activity guidelines about 20 minutes per day of moderate exercise isn’t enough to counter the hazards of spending most waking hours in a seat.

The authors analyzed data from participants ranging in age from 28 to 49, average age 33, from CU’s Colorado Adoption/Twin Study of Lifespan behavioral development and cognitive aging, which has followed twins and adopted individuals since childhood.

On average, participants reported sitting almost 9 hours daily, with some sitting as much as 16 hours. They reported between 80 and 160 minutes of moderate physical activity on average weekly and less than 135 minutes of vigorous exercise weekly.

The researchers looked at two key measures of heart and metabolic aging: total cholesterol/high-density lipoprotein and body mass index (BMI). The study found that, essentially, the more one sat, the older one looked. And adding a little moderate activity on top of a long day of sitting did little to buffer these impacts.

In fact, young adults who sat 8.5 hours per day and performed at or below current exercise recommendations could enter a “moderate to high risk” category for cardiovascular and metabolic disease, the authors said. When looking at a subset of twins with different sitting and physical activity habits, the researchers found that replacing sitting with exercise seemed to work better to improve cholesterol than simply adding exercise to a full day of sitting.

Reference: Bruellman R, Pahlen S, Ellingson JM, Corley RP, Wadsworth SJ, Reynolds CA (2024) A twin-driven analysis on early aging biomarkers and associations with sitting-time and physical activity. PLoS ONE 19(9): e0308660. https://doi.org/10.1371/journal.pone.0308660