Tai Chi’s Impact on Heart Health -- Measuring "Complexity"
by Patrick Dillon, Ph.D.
A recent two-part study measuring complexity of heart rate dynamics may point to a link between long-term Tai Chi training and overall cardiovascular system health, according to a paper from a team of researchers led by Yan Ma and published online this year in Scientific Reports, an open-access journal from Nature Reports.
The first part of the study conducted a cross-sectional comparison between a group of long-term Tai Chi practitioners and a Tai Chi naïve control group. Researchers found Tai Chi experts exhibited significantly greater heart rate variability complexity when compared to their naïve counterparts---an indication of overall healthier and more adaptable cardiovascular system dynamics.
In the second part, the Tai Chi naïve were randomly assigned to either a group that underwent six months of Tai Chi or to a waitlist control group. Although there were no statistically significant differences in either group after six months in complexity of heart rate dynamics, there were non-significant trends toward increased complexity among the Tai Chi group.
The authors concluded that long-term Tai Chi mind-body training may be associated with increased complexity of heart rate dynamics in healthy adults. Although the differences between the two groups were too small to indicate a cause-and-effect relationship, the authors propose that longer durations of Tai Chi training in the future investigations may result in larger effects.
Measuring the complexity of physiological control systems as an indicator of health (as this study did with heart rate variability) is a growing interest among researchers.
One reason is that complex physiological control systems---systems with many interacting components working together to adapt to a task or external stressor—are believed to provide the individual with greater resilience and robust health.
Another reason is that aging and disease are associated with a loss of such complexity. Because Tai Chi is a holistic, mind-body exercise that intends to impact and integrate many physiological systems, it seems logical that various health benefits of Tai Chi may arise by enhancing physiological complexity.
Other recent studies have already reported on Tai Chi’s association with gait and balance system complexity. This study on Tai Chi’s link to cardiovascular system dynamics adds to an expanding body of research on how Tai Chi may promote health by optimizing physiological complexity.
