It has been known for several centuries that relaxation and relaxation exercises do not only counteract the negative effects of stress, pain, and other neuropsychological disorders, but are also beneficial on their own and can ameliorate performance. However, one important open question still remains: How long does a relaxation exercise have to be in order to produce significant effects on subjective and objective measures of relaxation? To address this issue, we are planning a series of experiments using the well-known relaxation technique Progressive Muscle Relaxation (PMR). In the experiments, participants will be randomly assigned to different PMR durations (ranging from only 1 minute to 30 minutes). Subjective relaxation will be measured with the Relaxation State Questionnaire (RSQ). For objective relaxation, three different measures will be used: Pulse, blood pressure, and baseline pupil diameter. Both the subjective and objective measurements will be collected before and after the relaxation exercise. Mixed ANOVAs will be performed to compute differences before vs. after the exercise and for the differences between the PMR durations.
If effects can be found even after the short PMR exercise, this can be an important implication for future studies, giving first hints on how long relaxation exercises in experiments need to be in order to produce significant effects. Also, differences between the subjective feeling of relaxation and the objective measurements (or even between the three objective measurements) can be very insightful regarding the sensitivity of the different measurements to various PMR durations.