STUDY PROTOCOL Open Access Effects of a 6-week, whole-body vibration strength-training on depression symptoms, endocrinological and neurobiological parameters in adolescent inpatients experiencing a major depressive episode (the “Balancing Vibrations Study”): study protocol for a randomized placebo- controlled trial Max Oberste 1* , Nicola Großheinrich 2 , Heidrun-Lioba Wunram 1 , Johannes Levin Graf 1 , Alischa Ziemendorff 1 , Axel Meinhardt 1 , Oliver Fricke 3 , Esther Mahabir 4 and Stephan Bender 1 Abstract Background: Moderate to vigorous endurance and strength-training exercise was suggested as a treatment option for major depression. However, there is little evidence to support this suggestion in adolescent patients. The present study investigates the effects of a whole-body vibration strength-training intervention on symptoms in medication- naïve adolescent inpatients experiencing a major depressive episode. Potential underlying endocrinological and neurobiological mechanisms are explored. Methods/design: A double-blinded randomized controlled trial is conducted at the University Hospital of Cologne in Germany, comparing a 6-week, whole-body vibration strength-training with a 6-week placebo-intervention, as add-on therapy to inpatient treatment as usual. Forty-one subjects (13–18 years of age) will be included in each of the two groups. The study is powered to detect (α = .05, β = .2) a medium effect size difference between the two groups (d = .5) in terms of patients’ change in the Children’s Depression Rating Scale raw-score, from baseline until the end of the intervention. As secondary endpoints, the effects of exercise treatment on patients’ cortisol awakening response as well as on brain-derived neurotrophic factor, insulin-like growth factor 1 and inflammatory markers (tumor necrosis factor-alpha, interleukin-6 and C-reactive protein) serum levels will be assessed. (Continued on next page) * Correspondence: max.oberste-frielinghaus@uk-koeln.de 1 Department of Child and Adolescent Psychiatry and Psychotherapy, Medical Faculty, University of Cologne, Robert-Koch-Straße 10, 50931 Cologne, Germany Full list of author information is available at the end of the article © The Author(s). 2018 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Oberste et al. Trials (2018) 19:347 https://doi.org/10.1186/s13063-018-2747-8