EFFECTS OF AN EIGHT WEEK MODIFIED HATHA YOGA ON THE HEART RATE VARIABILITY & STRESS RESPONSE IN INJURED WORKERS

Abstract

The purposes of this study were 1) to evaluate the effects of modified hatha yoga on the injured
workers after training for 8 weeks, and 2) to measure heart rate variability (HRV), stress responses, and
physical fitness changes in the industrial injured workers. Twenty-six subjects (13 injured workers (IW) and 13
control normal workers (CN), aged between 18 to 60 years, volunteered to participate in this study. All
participants were measured HRV, stress responses parameters including electromyography (EMG),
respiratory rate, skin temperature and skin conductance. IW group were further divided into two groups;
hatha yoga injured workers (YIW) (n=7) and control injured workers (CIW) (n=6). YIW group performed 60-
minute/day, 3 days/week for 8 weeks of modified hatha yoga and then all parameters were measured again.
Results showed that IW group had a significant increase in LF/HF ratio of HRV (2.41) and skin conductance
(2.18 μS) compared to the CN group (HRV= 1.61, skin conductance = 1.24 μS) (p < 0.05).
Conclusion: The injury from industrial work disturb balance of PNS and SNS activity. And the 8 week
modified hatha yoga could not improve HRV and stress response in YIW group.
(Journal of Sports Science and Technology 2016; 16(1) : 55-64)
Keywords: Heart rate variability, Workers, Modified hatha yoga
*Corresponding author : Pensinee Panasiriwong
College of Sports Science and Technology, Mahidol University,
Phutthamonthon, Nakorn pathom, Thailand 73170
E-mail: mai.br91@gmail.com