Can exercise reverse the health risks of being sedentary? New research suggests vigorous activity may help

Research shows that 30 minutes of vigorous exercise every day may reduce the aging effects of sitting for long periods of time, but it's still important to reduce the amount of time you spend sitting.

study: Twin analysis of the association between early aging biomarkers and sedentary time and physical activity. Image credit: Stock-Asso/Shutterstock.com

In a recent study published in PLoS ONEThe group of researchers investigated the interaction between physical activity intensity and sedentary behavior in influencing health outcomes, with a particular focus on cardiovascular and metabolic biomarkers in adults aged 28 to 49 years.

background

Due to changes in work environments and the use of technology, prolonged sitting is becoming more common in developed countries. The coronavirus disease 2019 (COVID-19) pandemic has exacerbated this trend, with many U.S. adults sitting for more than eight hours each day.

A sedentary lifestyle can lead to adverse health conditions, especially in the cardiovascular and metabolic areas, and increase the risk of death comparable to obesity and smoking. Furthermore, prolonged sitting is correlated with obesity and dyslipidemia, highlighting the need to understand its relationship with aging.

Investigating these dynamics is essential to developing effective public health strategies to address the health consequences of sedentary behavior. Further research is required to unravel these complex interactions.

About research

Participants for this study were selected from the Colorado Adoption/Twin Study on Lifespan Behavioral Development and Cognitive Aging (CATSLife), with recruitment occurring from July 2015 to March 2021. The sample included 1,327 individuals (53% female) with a mean age of 33.2 years. year (SD = 4.9).

Ethical approval was obtained from the Institutional Review Boards of the Behavioral Genetics Institute at the University of Colorado Boulder and the University of California, Riverside. Informed consent was obtained from all participants.

The CATSLife cohort consists of two groups. One is the Colorado Adoption Project, which includes adopted and non-adopted siblings, and the other is Longitudinal Twins, which consists of pairs of same-sex identical twins (MZ) and dizygotic twins (DZ). It's research.

To reduce confounding factors, certain exclusion criteria were applied, including current pregnancy, non-fasting status during blood collection, and participants not completing required measurements. This resulted in 921 participants for total cholesterol (TC)/high-density lipoprotein (HDL) analysis and 937 participants for body mass index (BMI) analysis. Sedentary behavior was self-reported and physical activity level was assessed through a leisure-time activity screening questionnaire.

Health biomarkers such as BMI, TC, and HDL were measured through in-person visits and fasting blood samples. The analysis strategy included using linear mixed effects models to examine the relationship between lifestyle factors and health outcomes while accounting for covariates such as gender, age, and dietary intake.

Co-twin control analyzes were also performed to distinguish between family and environmental influences on health indicators. Further sensitivity analyzes on discordant MZ twin pairs provided insight into how physical activity can offset the health risks associated with prolonged sitting.

Research results

Descriptive statistics for key indicators showed that participants reported sitting for an average of 60.07 hours per week, which equates to approximately 8.58 hours per day. The distribution of sitting time was approximately normal, and there were no significant gender differences in mean sitting time.

However, significant differences were observed between men and women in various measures such as metabolic equivalents (METs) of vigorous tasks, fruit and vegetable intake, BMI, and TC/HDL ratio, with men having higher values. (p ≤ .005). . The correlation between BMI and TC/HDL was moderate, evidenced by a Spearman rank correlation coefficient of 0.41.

Linear mixed effects (LME) models were used to analyze sociodemographic effects on TC/HDL and BMI. Results showed that age and gender significantly influenced both outcomes, with age significantly associated with increased TC/HDL (B = 0.029, p < .001) and BMI (B = 0.087, p = .004). showed a positive correlation.

Although race and ethnicity had no significant results, they were retained in subsequent models. Nonlinear trends were investigated and found to be insignificant. The results of this study suggest that increased active MET is associated with a decreased TC/HDL ratio, while older age, male gender, and increased sedentary time are associated with worse TC/HDL outcomes. did.

Although a healthy diet was associated with lower TC/HDL ratios, these effects were not statistically significant. Specifically, a 30-year-old person who sits for an average of 4 hours each day has a TC/HDL comparable to a 35-year-old person who exercises vigorously for 30 minutes each day.

A similar pattern was seen for BMI, showing that people who adhered to exercise recommendations were able to maintain a TC/HDL ratio that placed them in the moderate risk category for cardiovascular problems in early adulthood.

Co-twin control analyzes showed significant within-pair effects for sedentary and vigorous physical activity on TC/HDL, suggesting possible exposure effects rather than familial confounding. However, the MZ within-pair effect on vigorous activity was small, indicating partial confounding. A between-pair effect on vigorous exercise was observed, but it was not significant.

In the discordant MZ twin analysis, twins who spent less time sedentary and engaged in more vigorous activity had lower TC, especially when sedentary time was replaced with vigorous activity at a rate of at least 10 minutes of exercise for every sedentary time. /HDL ratio.

Conversely, the active compensator group required much more vigorous activity to achieve similar TC/HDL levels compared to the active replacer group, with a significant impact on health status within the twin pair. Differences in the effects of physical activity were highlighted.

conclusion

In summary, the findings show that sitting has negative health effects and that current exercise recommendations do not fully alleviate these effects.

Engaging in vigorous activity is associated with healthier TC/HDL and BMI levels, and people who sit for 8.5 hours daily still have moderate heart risk.

Co-twin control analysis highlights the importance of going beyond current exercise guidelines. Furthermore, fruit and vegetable intake was significant for BMI but not correlated with TC/HDL, indicating a complex influence of diet.