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.