Even youth is not a shield. It has been found that a sedentary lifestyle accelerates aging and increases the risk of heart disease by speeding up the biological clock, regardless of age.
Millennials born between the early 1980s and early 2000s were found to spend more than 60 hours (35.7%) per week sitting due to long commuting times, a computer-based work environment, and consuming social media or streaming content in the evening after work. If you live for a long time, the risk of age-related diseases such as heart disease can increase relatively quickly.
Researchers from the University of Colorado at Boulder and the University of California, Riverside, surveyed more than 1,000 current and former Colorado residents, including 730 twins, to determine how sitting for long periods of time affects key health indicators in young adults, published in the journal Plasma. It was published in PLOS ONE.
“Young adults tend to think that the effects of aging have nothing to do with them. They think, ’My metabolism is good, so I don’t have to worry about it until I’m in my 50s or 60s.’ But what you do during these critical times in your life matters,” lead author Ryan Bruelmann, a researcher at the University of California, Riverside, said in a related statement.
The study was conducted with participants aged 28 to 49 (average age 33). They answered that they sit for an average of 8.58 hours every day, with some sitting for up to 16 hours. They averaged between 80 and 160 minutes of moderate-intensity physical activity each week, and less than 135 minutes of vigorous-intensity physical activity per week. This figure is better than the national average, which researchers say is due to Colorado’s active lifestyle.
The researchers measured two key indicators of cardiovascular and metabolic health: body mass index (BMI) and the ratio of total cholesterol to high-density lipoprotein cholesterol (TC/HDL), also called the cardiac risk ratio. In general, higher levels indicate increased health risks.
The results of the study showed that people who sat for long periods of time had a higher BMI and TC/HDL ratio even if they met the minimum recommended physical activity guidelines of 20 minutes of moderate exercise per day. This means that he looked physically older. In fact, young adults who sit for 8.5 hours a day and exercise less than the recommended amount could fall into the ‘moderate to high risk’ category for cardiovascular and metabolic disease, the authors noted.
Vigorous exercise buffered the negative effects of sitting for long periods of time. Participants who did 30 minutes of high-intensity exercise every day, such as running or pedaling a bicycle until they were out of breath, showed similar health indicators as people 5 to 10 years younger who spent the same amount of time sitting but did not engage in vigorous exercise.
However, even this level of physical activity did not completely neutralize the negative effects of sitting for long periods of time. In particular, sitting for 8 hours a day did not completely offset cardiovascular risk factors even if the minimum standard of exercise guidelines of ‘150 minutes of moderate-intensity or 75 minutes of high-intensity exercise per week’ was met.
Studies of identical twin participants, who share 100% of their genes, have been particularly useful in understanding this relationship. After examining twins who had different sitting times and exercise habits, researchers found that replacing sitting time with exercise was more beneficial to cholesterol levels than adding exercise while maintaining the same amount of sitting time.
“Our study suggests that reducing the amount of time spent sitting throughout the day, engaging in more vigorous exercise, or a combination of the two may be necessary to reduce the risk of premature aging in early adulthood,” said senior author Chandra Reynolds. said a professor at the University of Colorado at Boulder.
This study provides strong evidence that reducing sedentary time and increasing vigorous exercise is important for maintaining cardiovascular and metabolic health in early adulthood. Accordingly, the researchers suggested that current physical activity guidelines need to be adjusted to reflect the amount of time spent sitting per day.
According to the Korea Disease Control and Prevention Agency, high-intensity exercise refers to strenuous activity that is ‘at a level that makes it difficult to hold a conversation.’ Examples include activities that make your heart beat faster, such as running (more than 8 km per hour), which consumes more than 6 times more energy than sitting still, cycling uphill, jumping rope more than 100 times per minute, high-intensity interval training, and vigorous swimming.
the researchers advised trying both of the following:
First, to reduce sitting time at work, use a standing desk and plan meetings where you move your body and walk even briefly during breaks.
Second, if possible, exercise at a level that leaves you feeling out of breath for at least 30 minutes a day, or become a ‘weekend warrior’ who can do longer and more intense exercise.
참고자료: A twin-driven analysis on early aging biomarkers and associations with sitting-time and physical activity(-
Time.news Interview: Understanding Sedentary Lifestyles and Their Impact on Aging
Interviewer (Editor of Time.news): Welcome, everyone, to another engaging discussion on health and wellness. Today, we’re diving into a fascinating yet alarming study about how sedentary lifestyles can accelerate aging and increase the risk of heart disease. Joining us is Ryan Bruelmann, a researcher from the University of California, Riverside, and one of the lead authors of the study. Ryan, thank you for joining us.
Ryan Bruelmann: Thank you for having me! It’s a pleasure to be here.
Editor: Let’s get right to it. Your study focused on millennials and their sitting habits. What were some of your key findings regarding how prolonged sitting impacts health, particularly for younger adults?
Ryan: One of our main observations was that millennials, who spend an average of over 8.5 hours a day sitting, are at a higher risk for age-related diseases, such as heart disease, even when they think they’re in good health. What surprised us was the extent to which this sedentary lifestyle affects key health indicators like body mass index (BMI) and cholesterol levels.
Editor: That sounds concerning. You mentioned that millennials often believe their youth protects them from health problems. Why do you think there’s a disconnect between their behaviors and the potential long-term consequences?
Ryan: Young adults tend to think their fast metabolism and energy levels shield them from aging-related health issues. They often believe they can procrastinate on fitness until they hit their 50s or 60s. However, our study underscores that these early years are critical for building a health foundation, and neglecting physical activity can accelerate biological aging.
Editor: The study involved a significant number of participants, including identical twins. How did this methodology enhance your findings?
Ryan: Studying identical twins was instrumental because they share 100% of their genetic material, allowing us to isolate environmental factors, particularly sitting and exercise habits. This approach showed us that reducing sitting time can lead to much better cholesterol levels and overall health, even more so than merely adding exercise to their routine.
Editor: It’s interesting to hear that replacing sitting time with exercise is more beneficial than simply doing extra workouts. What kind of physical activity did you see as most effective in countering the negative impacts of sitting?
Ryan: Our research indicated that vigorous exercise—like high-intensity interval training, running, or cycling—was particularly effective. Participants who engaged in 30 minutes of high-intensity exercise daily exhibited health indicators similar to individuals 5 to 10 years younger, despite the amount of time they spent sitting.
Editor: While that’s encouraging, it seems like even vigorous exercise didn’t completely negate the negative effects of prolonged sitting. Is that correct?
Ryan: Exactly. Even with the recommended levels of exercise—150 minutes of moderate activity or 75 minutes of high-intensity exercise per week—participants who also sat for extended periods still showed concerning cardiovascular risk factors. The key takeaway here is that reducing sitting time should accompany regular exercise for optimal health.
Editor: So, for our readers hearing this news, what actionable steps can they take to mitigate the risks associated with prolonged sitting?
Ryan: I suggest incorporating more movement into your day. Simple changes like taking short breaks to stand up, walk around, or engage in stretches can make a significant difference. If possible, consider standing desks or investing time in activities that replace sitting, like walking meetings or biking to work. Every bit counts!
Editor: Excellent advice! Lastly, Ryan, do you see a potential shift in public health messaging to address these issues moving forward?
Ryan: Absolutely. As awareness grows about the detrimental effects of sedentary lifestyles, I believe we’ll start to see a more concerted effort in public health campaigns emphasizing the importance of movement, not just in the context of exercise but as a daily part of our lives. It’s crucial for younger populations to understand that their current choices impact their future health.
Editor: Thank you, Ryan, for sharing these invaluable insights on this pressing issue. Looking ahead, it’s essential for all of us to rethink our daily habits to foster a healthier future.
Ryan: Thank you for the opportunity to discuss this important research!
Editor: And thank you to our audience for tuning in! Stay active, stay healthy, and until next time, take care!