A COMPARISON OF HIGH FREQUENCY YOGA BREATHING (HFYB) WITH BREATH AWARENESS (BAW) AND AEROBIC EXERCISE ASSESSING NEUROPLASTICITY BY GAMMA OSCILLATION, BDNF LEVELS, AND COGNITIVE TASK PERFORMANCE.

Abstract

BACKGROUND: Cognitive task performance is generally accompanied by increased sympathetic nervous system (SNS) activity, regional cerebral blood flow (rCBF), brain oscillations, and elevated brain-derived neurotrophic factor (BDNF) levels. Cognitive abilities such as working memory (WM) are essential for daily functioning and are also critical for higher-order processes, including planning and problem-solving. AIM: The study aims to assess the effect of Kapalabhati or high-frequency yoga breathing (HFYB) on BDNF levels, gamma brain oscillations, and performance in one cognitive task, compared with running and breath awareness (BAW). METHODS: Participants: Forty-eight yoga practitioners, aged 18 to 35 years, were recruited for the study. Participants having more than 6 months of yoga experience are willing to participate in the study and adhere to the study’s protocols. Male subjects alone were studied, as some studies have found that female autonomic, cognitive functions, and respiratory variables can be modulated by the phases of the menstrual cycle. Design: The study was a 3-arm randomized controlled trial with assessments conducted at the beginning and immediately after HFYB, including running and breath awareness exercises. Assessment: The pre- and post-assessments included cognitive function (working memory or N-back task), Cardiorespiratory/autonomic variables (Heart rate variability, energy expenditure, and metabolic rate), biochemical measurements (BDNF level), and Brain waves or oscillations (electroencephalography-EEG). Intervention: Participants received a 15-day orientation to ensure uniformity in practice. The Kapalabhati group practiced HFYB for 15 minutes (three rounds of 5 minutes each, with a 1 minute break in between). The running and breath awareness groups followed the same schedule for an equal duration. RESULT: The running group exhibited continuous parasympathetic withdrawal in both pre-WM and post WM periods (p < 0.01). In the HFYB group, parasympathetic withdrawal was observed during pre WM and practice; however, parasympathetic activity was re-established post-WM, suggesting a modulatory effect. WM accuracy improved in all groups (p < 0.05), while reaction time decreased (p < 0.05). A statistically significant increase in BDNF levels (p < 0.01) was observed only in the HFYB group, with no significant changes in the others. The running group showed significant increases in metabolic rate and energy expenditure (p < 0.05) in both within- and between-group comparisons. Spectral analysis revealed a significant increase in alpha waves in the frontal region (p < 0.05) and gamma power (p < 0.05) during HFYB practice. HFYB also showed significant changes across the frontal, temporal, and occipital regions. CONCLUSION: The findings suggest that HFYB can modulate vagal tone and parasympathetic activity while improving working memory performance. The parasympathetic reactivation observed may be cardioprotective, thereby promoting better health and longevity. Spectral analysis also showed enhanced alpha power in the frontal region and increased gamma oscillations in the fronto temporal-occipital regions, indicating that HFYB may improve higher cognitive functions by increasing cortical activity. Thus, HFYB may serve as a cost-effective, neuroprotective practice for promoting cognitive health. Keywords: High frequency yoga breathing, Heart rate variability, working memory, Brain derived neurotrophic factor (BDNF), brain oscillation.