Today, on average, and in rich countries, adults sit for more than 60 hours per week. Prolonged sitting and, more broadly, an increase in sedentary lifestyle, already known as a major factor in heart disease and accelerated aging.
The study conducted with more than 1,000 participants, including 730 twins, is one of the first to explore the impact of prolonged sitting on objective health measures, such as cholesterol and body mass index (BMI). in young adults. The analysis finds that:
- respecting physical activity recommendations, i.e. approximately 20 minutes per day of moderate exercise, is not enough to counter the harmful effects of prolonged sitting;
- it is necessary to reduce the duration of sitting and engage in intense exercise to reduce the risk of premature aging linked to this form of sedentary lifestyle;
One of the lead authors, Dr. Chandra Reynolds, professor of psychology and neuroscience at the University of Colorado Institute for Behavioral Genetics, notes: “Young adults tend to think they are immune to the effects of aging. They say to themselves:
“My metabolism is excellent, I don’t have to worry until I’m 50 or 60.”
However, this form of sedentary lifestyle during this young adult period also counts.”
Analysis of data from participants in the CATSLife cohort (Colorado Adoption/Twin Study of Lifespan behavioral development and cognitive aging) aged 28 to 49, with an average age of 33, reveals precisely that:
-- participants sit for an average of almost 9 hours a day, some up to 16 hours;
- participants engage in an average of 80 to 160 minutes of moderate physical activity per week and less than 135 minutes of vigorous exercise per week;
- the longer they sit, the older they appear;
-
a little more moderate activity has no effect;
- Young adults who sit 8.5 hours per day and engage in physical activity at or below current recommendations are, based on standard biomarkers, at moderate to high risk for cardiovascular and metabolic diseases.
- Taking a short walk in the evening is not enough, only practicing an intense activity actually has a prevention effect.
- In case of prolonged sitting, practicing 30 minutes of intense exercise per day is necessary to maintain normal cholesterol levels and a healthy BMI;
- but even such vigorous activity cannot completely eliminate the negative effects of prolonged sitting.
Data analysis of twins with different sedentary and physical activity habits shows that replacing sitting with strenuous exercise is necessary to improve cholesterol – rather than simply adding exercise to a sedentary day.
Finally, young adulthood is the time to develop habits that are beneficial for long-term health.
Morocco