RESUMO
OBJECTIVES: To assess the benefits of training in mindfulness-based stress reduction (MBSR) or moderate intensity exercise (EX) for improving sleep quality. DESIGN: Randomized controlled trial. SETTING: Outpatient, community-based. PARTICIPANTS: Healthy adults (n = 413) aged 30-69 who did not regularly exercise or practice meditation, and who had no known prior sleep problems. INTERVENTIONS: 1) 8-weeks of MBSR training; 2) matched EX training; or 3) wait-list control. MEASUREMENTS: The Pittsburgh Sleep Quality Index (PSQI) was administered at baseline and at 1, 3, 5, and 7-month follow-up visits. ANALYSIS: Total PSQI scores and three PSQI factors (perceived sleep quality; daily disturbance, sleep efficiency) were assessed using linear mixed effects regression models for longitudinal data. RESULTS: Compared to controls, PSQI global scores improved significantly for EX (mean change -0.98 points [95% CI -1.56, -0.41] p = 0.001) and marginally for MBSR (-0.53 [-1.10, 0.04] p = 0.07). The perceived sleep quality factor improved for both EX (-0.18 [-0.30, -0.07] p = 0.002) and MBSR (-0.12 [-0.24, -0.01] p = 0.035). The daily disturbance factor improved slightly more for MBSR (-0.13 [-0.22, -0.033] p = 0.008) than EX (-0.09 [-0.19, 0.004] p = 0.06). The sleep efficiency factor did not improve after MBSR (0.08 [-0.045, 0.21] p = 0.2) or EX (-0.07 [-0.20, 0.06] p = 0.3). Improvements in the sleep quality were sustained over 7 months for both groups. CONCLUSIONS: Training in MBSR and EX produced small but statistically significant and sustained improvements in sleep quality. For EX participants, this improvement was due primarily to improvements in perceived sleep quality. For MBSR, the decrease in daily disturbance was more important.