Improving Trip and Slip-Resisting Skills in Older People: Perturbation Dose Matters Aging negatively affects balance recovery responses following trips and slips. We hypothesize that older people can benefit from brief treadmill-based trip and slip-perturbation exposure despite reduced muscular capacities, but with neuropathology their responsiveness to these perturbations will be decreased. Thus, to facilitate long-term benefits and their generalizability to everyday life, one needs to consider the individual threshold for perturbation dose. Author for correspondence: Kiros Karamanidis, 103 Borough Rd, London SE1 0AA, k.karamanidis@lsbu.ac.uk. (Tel. +44 20 7815 7991) Conflicts of interest: The authors declare no conflicts of interest. Disclosure of funding received: This study did not receive support from any funding bodies or grants and all authors declare no conflicts of interest. © 2019 American College of Sports Medicine

Passive versus Mentally Active Sedentary Behaviors and Depression Detrimental associations of sedentary behaviors with depression have been identified, but findings are inconsistent. We propose a novel approach to the classification and analysis of sedentary behaviors, which differentiates between those that are passive (e.g., TV viewing) and mentally active (e.g., reading). Available evidence is summarized, and research questions relating to measurement, causal relationships and mechanisms are considered. Corresponding author: Mats Hallgren, Solnavägen 1e, level 6, 113 65 Solna, Sweden. mats.hallgren@ki.se. Funding: Owen is supported by a National Health and Medical Research Council of Australia (NHMRC) Centre of Research Excellence Grant (#1057608), NHMRC Senior Principal Research Fellowship (#1118225), and the Victorian Government’s Operational Infrastructure Support Program. Dunstan is supported by a NHMRC Senior Research Fellowship #1078360 and the Victorian Government’s Operational Infrastructure Support Program. Conflicts of interest: None to declare. © 2019 American College of Sports Medicine

A Critical Review of Exercise Training in Hemodialysis Patients: Personalized Activity Prescriptions are Needed Exercise training appears to have modest or inconsistent benefits in hemodialysis patients. This may be due to the low volume and intensity of exercise often prescribed. To address this, research is needed to evaluate the efficacy of individualized exercise prescriptions as a component of a comprehensive lifestyle intervention strategy that gives patients more autonomy to choose preferred types of physical activity. Corresponding Author: Ken Wilund, PhD. Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign. 906 S. Goodwin Avenue, Urbana, Illinois, 61801. Phone: 217-419-4087, kwilund@illinois.edu Funding Disclosure: The work described was supported by Award Number R01DK084016 from the National Institute of Diabetes And Digestive And Kidney Diseases. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institute of Diabetes And Digestive And Kidney Diseases or the National Institutes of Health. Conflicts of Interest: None © 2019 American College of Sports Medicine

Exercise Intolerance in Heart Failure: Central Role for the Pulmonary System We propose that abnormalities of the pulmonary system contribute significantly to the exertional dyspnea and exercise intolerance observed in patients with chronic heart failure. Interventions designed to address the deleterious pulmonary manifestations of heart failure may therefore yield promising improvements in exercise tolerance in this population. Corresponding author: Sophie Lalande, PhD, Department of Kinesiology and Heath Education, The University of Texas at Austin, 2109 San Jacinto, UT Mail Code: D3700, Austin, TX 78712, (512) 232-6485; sophie.lalande@austin.utexas.edu Disclosure of funding received for this work: This work was supported by NIH Grant HL071478. Bryan J. Taylor and Sophie Lalande were supported by American Heart Association Postdoctoral Fellowships (12POST12070084 and 0920054G, respectively). Troy J. Cross was supported by an Australian Postgraduate Award. Manda L. Keller-Ross was supported by a NIH/NIAMS T32AR56950 grant. Conflicts of interest: None © 2019 American College of Sports Medicine