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Results of a Stress Management Program for Graduate Students Based on Relaxation Associated with HRV Biofeedback

    • IND PR
    • Daniela Climov, Ph.D.
    • Pedagogical and Statistical Unit, Institut d'Enseignement Supé rieur (IES) Parnasse-Deux Alice, Haute Ecole Lé onard de Vinci.
    • Download the complete paper, click here.



The objective of our intervention is to help students overcome stress and anxiety, by introducing them to a new stress management technique, and heart rhythm coherence biofeedback (cardiac coherence). They can thus best know themselves and gain more confidence in their resources.

Introduction and Background

In the present study, we use the emWave® PC/Mac (formerly Freeze-Framer) system to measure the degree of coherence attained by using a combination of relaxation techniques inspired from "sophrology" and HRV biofeedback.

Sophrology is a holistic relaxation method, proposed by Caycedo in 1970 [7], which uses respiration, dynamic exercises and static relaxation techniques. It develops the awareness of one’s body, of the muscles tension/relaxation and of a calm state of mind. Starting from the physical relaxation of the muscles one achieves the "sophro-liminal" level, which leads to a harmonious state of being (physical, mental and emotional).

HRV coherence biofeedback uses the heart rate variability HRV, captured by plethysmography and displayed on the computer screen in real-time using the emWave® PC/Mac (formerly Freeze-Framer) system, developed by the Institute of HeartMath. HRV measures the amount of variability in the beat-to-beat heart rate. It is an important physiological index of stress and has been described in a number of studies [3, 8, 13].

Research conducted by the Institute of HeartMath [10] on the link between heart rhythms and emotions has introduced and developed the notion of "coherence". The coherence is defined as a "distinct mode of physiological functioning that is associated with the experience of heartfelt positive emotions". The physiological coherence result in a highly efficient state in which body and brain function with increased harmony.

On the screen, correlates of coherence include a smooth, sine-wave pattern in the HRV graph. By displaying their HRV pattern on the computer screen, students were able thus to see when they were in coherence or not.

In the last decade, HRV coherence biofeedback has been used in education in various settings with good results [1, 2, 4, 9, 10, 12]. It has been found to directly correlate with improvements in cognitive performance: increasing focus, attention, and reduction in the perception of stress.


The intervention consisted of 10 sessions of stress management using sophrology and HRV coherence biofeedback (1 hour, once a week, from October 2007 to May 2008).

We used the emWave® PC/Mac (formerly Freeze-Framer® program from session 2 to 10. As we had less Freeze-Framer units than students, each student used it approximately 4 times along the 10 sessions.

Several stress management techniques were used:

  • "sophrology" exercices, inspired from yoga, including progressive muscle relaxation.
  • Static "sophrology" techniques of relaxation and visualisation, autogenic training and the Rapid Coherence Technique proposed in the emWave® PC/Mac (formerly Freeze-Framer) user’s guide.
  • Information about HRV and its relations to respiration, well-being, and coherence.
  • Biofeedback using emWave® PC/Mac (formerly Freeze-Framer), using the HRV (heart rate variability) screen starting from session 2. For the last 3 sessions students had the possibility to train using the Freeze-Framer games.
  • Discussion about "coherence" from the students point of view (balance between resources and limitations).

Students followed their HRV pattern and the coherence ratio on the screen as indicators of the degree of coherence achieved as a result of the relaxation exercises associated to biofeedback.


The results are as following (all the statistical tests are in the Appendix):

Stress scores: The stress reduction that occurred with the stress management program is greater than would be expected by chance; there is a statistically significant reduction of stress (p-value = 0.009 paired t-test) from the beginning to the end of the program.