A Finnish twin study by the University of Jyväskylä reveals that moderate exercise may have the most significant impact on reducing mortality rates and that higher activity levels don’t necessarily offer extra benefits. The research also questions the effectiveness of adhering to global physical activity guidelines on genetic disease risk and longevity.
In a breakthrough study, researchers from the University of Jyväskylä in Finland have shed new light on the relationship between physical activity and life expectancy, challenging current beliefs about the benefits of exercise for longevity and genetic disease risk.
Study Parameters and Findings
The research, published in the European Journal of Epidemiology, analyzed data from 22,750 Finnish twins born before 1958. The participants’ leisure-time physical activity was monitored over 15 years, with activity levels documented in 1975, 1981 and 1990. Mortality rates were tracked up until the end of 2020.
Four distinct groups were identified based on activity levels: sedentary, moderately active, active and highly active. The analysis revealed that the most significant reduction in mortality risk — a 7% decrease — occurred between the sedentary and moderately active groups. However, higher levels of physical activity did not confer additional benefits in terms of longevity.
When mortality was examined in the short term, a higher level of physical activity appeared to lower mortality risk. In the long term, however, highly active individuals did not differ from sedentary ones in terms of mortality.
Beyond Physical Activity Guidelines
The study also delved into whether meeting the World Health Organization’s (WHO) physical activity guidelines — 150-300 minutes of moderate activity or 75-150 minutes of vigorous activity weekly — affects mortality and genetic disease risk.
Surprisingly, the results indicated no significant difference in mortality rates between those who adhered to these guidelines and their less active twin counterparts.
“The widely observed favorable association between physical activity and mortality are based on observational studies that are prone to bias from different sources,” co-first author Laura Joensuu, a postdoctoral researcher from the Faculty of Sports and Health Sciences at the University of Jyväskylä, said in a news release. “In our studies, we aimed to account for various sources of biases, and combined with the long follow-up period, we could not confirm that adhering to physical activity guidelines mitigates genetic cardiovascular disease risk or causally reduces mortality.”
The U-Shaped Curve of Biological Aging
The researchers also looked into biological aging by examining a subsample of twins using epigenetic clocks, tools that estimate biological age based on changes in DNA methylation. Interestingly, they discovered a U-shaped relationship between physical activity and biological aging.
“We found that the association between leisure-time physical activity and biological aging was U-shaped: Biological aging was accelerated in those who exercised the least and the most,” added corresponding author Elina Sillanpää, an associate professor of health promotion at the University of Jyväskylä.
Other lifestyle factors, such as smoking and alcohol consumption, were also found to significantly influence biological aging.
Implications and Future Directions
This study, carried out in collaboration with the Finnish Institute of Molecular Medicine at the University of Helsinki, poses critical questions about the conventional wisdom that promotes high levels of physical activity as universally beneficial.
While moderate exercise showed a clear advantage in reducing mortality, extreme levels of activity did not show additional benefits and could, according to the researchers, even accelerate biological aging.
The findings invite further research to better understand the nuanced relationships between physical activity, genetic factors and longevity. They suggest a need for more personalized exercise recommendations, taking individual genetic predispositions and other lifestyle factors into account.
Source: University of Jyväskylä