Classical back massage is associated with lower heart rate and sustained mean skin conductance during recovery after cognitive load: an exploratory controlled pilot study.

Introduction: Physiological responses after cognitive load may differ across cardiovascular measures and electrodermal activity (EDA). Methods: This controlled exploratory pilot study compared heart-rate and phase-averaged mean skin-conductance responses during a 15-min post-task period conducted under two conditions: classical back massage and passive prone rest. After eligibility verification and physiological signal-quality inspection, the final analytical sample included 48 participants: 24 in the classical massage condition and 24 in the passive rest condition. Recordings were segmented into a 5-min baseline, the cognitive task, and three non-overlapping 5-min post-task windows. Heart rate and phase-averaged mean skin conductance were analyzed using mixed-design repeated-measures analyses of variance (ANOVA), with baseline-adjusted values reported descriptively and non-parametric analyses used as supplementary robustness checks. Results: During the post-task period, the massage group showed a lower heart rate than the passive-rest group across all recovery windows, whereas mean skin conductance remained elevated and was higher during the later windows. Discussion: These divergent trajectories suggest that cardiovascular and electrodermal measures capture different components of the post-load response and should not be treated as interchangeable indicators of autonomic recovery. The findings provide a basis for confirmatory studies using randomized allocation and active tactile controls, but remain hypothesis-generating because the design did not isolate somatosensory input, interpersonal contact, expectation, posture, or spontaneous recovery.