Vol.:(0123456789) 1 3 Sleep and Breathing https://doi.org/10.1007/s11325-021-02388-y NEUROLOGY • ORIGINAL ARTICLE Eight‑week high‑intensity interval training is associated with improved sleep quality and cardiorespiratory ftness in patients with depressive disorders Haitham Jahrami 1,2  · Ahmed S. BaHammam 3,4  · Brendon Stubbs 5,6  · Ali Sabah 1  · Zahra Saif 1  · Nicola Luigi Bragazzi 7  · Michael V. Vitiello 8 Received: 19 February 2021 / Revised: 14 April 2021 / Accepted: 21 April 2021 © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2021 Abstract Purpose This study aimed to examine the efect of high-intensity interval training (HIIT) on both sleep and cardiorespira- tory ftness in patients with depression. Methods Using a single pre- and post-test study design with no control group, 82 patients diagnosed with depressive dis- orders underwent HIIT comprising a total of 24 15-min sessions, three times per week for 8 weeks. Depressive symptoms, sleep quality, and cardiorespiratory ftness were evaluated using the Beck depression inventory-II, the Pittsburgh sleep quality index (PSQI), and cardiopulmonary exercise testing (CPET) in the form of maximum oxygen uptake (VO 2 max), respectively. Results All 82 patients completed the intervention. HIIT training was associated with signifcant improvements in BDI-II score (dif = − 1.57 [95% CI − 2.40 to − 0.73], P = 0.001), PSQI score (dif = − 1.20 [95% CI − 2.10 to − 0.32], P = 0.008), and CPET VO 2 max (dif = 0.95 [95% CI 0.62–1.28], P = 0.001). Efect size calculations revealed that the greatest improve- ment occurred in CPET VO 2 max (Cohen’s d = 0.64) and that improvements in the BDI-II and PSQI scores were somewhat smaller in magnitude (Cohen’s d = − 0.41 and − 0.30, respectively). Sleep quality improvements were observed in sleep latency, habitual sleep efciency, and the use of sleep-promoting medications (Cohen’s d = 0.18, 0.19, and 0.25, respectively). Change in cardiorespiratory ftness successfully predicted change in sleep quality but not in depressive symptoms. Adverse efects were limited to minor injuries which did not interfere with completion of training. Conclusions HIIT training delivered over 8 weeks was associated with improvements in depression symptoms, sleep quality, and cardiorespiratory ftness in patients with depressive disorders. Keywords Adjustment disorders · Aerobic exercises · Cardiovascular exercises · Interval training · Mood · Sprint interval training * Haitham Jahrami HJahrami@health.gov.bh 1 Ministry of Health, P.O. Box: 12, Manama, Bahrain 2 College of Medicine and Medical Sciences, Arabian Gulf University, Manama, Bahrain 3 Department of Medicine, College of Medicine, University Sleep Disorders Center, King Saud University, Box 225503, Riyadh 11324, Saudi Arabia 4 The Strategic Technologies Program of the National Plan for Sciences and Technology and Innovation in the Kingdom of Saudi Arabia, Riyadh, Saudi Arabia 5 Physiotherapy Department, South London and Maudsley NHS Foundation Trust, London, UK 6 Department of Psychological Medicine, Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King’s College London, London, UK 7 Laboratory for Industrial and Applied Mathematics (LIAM), Department of Mathematics and Statistics, York University, Toronto, ON, Canada 8 Psychiatry & Behavioral Sciences, Gerontology & Geriatric Medicine, and Biobehavioral Nursing, University of Washington, Seattle, WA 98195-6560, USA