TITLE:
Static Stretching Combined with Conscious Slower Breathing May Increase Parasympathetic Activity and Reduce Stress in Adult Women
AUTHORS:
Mami Sakurai, Yasushi Ikarashi, Masahiro Tabuchi, Ailing Hu, Takuji Yamaguchi, Hiroyuki Kobayashi
KEYWORDS:
Static Stretching, Conscious Slower Breathing, Autonomic Activity, Heart Rate Variability, Stress
JOURNAL NAME:
Health,
Vol.16 No.3,
March
29,
2024
ABSTRACT: Background: Women
are thought to be more susceptible to stress than men in a stressful society,
and reducing stress is crucial for women to maintain their health. Static
stretching (SST) is applied in various fields to not only increase muscle
flexibility but also reduce stress. Additionally, conscious slower breathing (CSB) predominates parasympathetic
activity, causing a relaxing effect. These results indicate that
combining SST and CSB may be more useful in reducing stress. However, to the
best of our knowledge, the effect of this combination remains unclear. Objective: This study aimed to elucidate the effects of the combination of SST and CSB on
autonomic activity and stress in adult women. Methods:Eleven
healthy Japanese adult female participants performed SST with nonconscious natural breathing for 20 min.The same participants performed SST in combination with
CSB (2 s
inspiratory and 4 s
expiratory) for 20 min on another day. Salivary
cortisol and chromogranin A levels were measured before and after stretching as
stress markers of the hypothalamic-pituitary-adrenal axis and sympathetic nervous system. The
coefficient of variation of the R-R interval (CVR-R) and high-frequency
component (HF), which reflect parasympathetic nerve activity, and heart rate
and low-frequency component (LF)/HF ratio, which reflect sympathetic nerve
activity, were measured before, during, and after stretching. Results: SST decreased cortisol levels but with no
significant changes in chromogranin A, heart rate, CVR-R, HF, or LF/HF
ratio. The combination of SST and CSB increased
CVR-R and HF levels in addition to decreasing cortisol levels but with
no significant changes in chromogranin A, heart rate, or LF/HF levels. Conclusion: These results indicate that the combination of SST and CSB may increase
parasympathetic activity and reduce stress. However, future
randomized controlled trials with larger sample sizes should support this
conclusion.