Learning to relax: The impact of brief biofeedback training and gentle yoga on salivary cortisol reduction

Short-term activation of the human stress response system is beneficial as it prepares the body to deal with stressors at hand (McEwen & Stellar, 1993 ). However, chronic activation of the system can negatively impact health and longevity (Cohen et al., 2007 ). There is evidence that relaxation techniques that utilize controlled or diaphragmatic breathing can be useful in the reduction of stress and psychological complaints. Short-term interventions like computer-based biofeedback or the implementation of a gentle yoga practice could provide a brief, yet beneficial, way to manage stress and anxiety. The present study aimed to expand on current research involving yoga and biofeedback for stress reduction by exploring whether participating in a gentle yoga intervention or a biofeedback intervention could decrease the stress response more quickly than what naturally occurs after the Trier Social Stress Test: a laboratory stress task shown to elicit changes in cortisol levels found in participants’ saliva samples. Participants were randomly assigned to take part in a gentle yoga sequence, a biofeedback intervention, or watch a neutral video while relaxing on their own. We examined changes in salivary cortisol levels and found a significant difference between the three groups, with both the yoga and biofeedback intervention groups eliciting a larger decrease in cortisol levels, indicating a greater decrease in stress levels.