FeaturesHIIT as a Tool for Improving Mental Health and CognitionHeisz, Jennifer J. Ph.D.; Marashi, Maryam B.Sc.; Nicholson, Emma B.Sc.; Ogrodnik, Michelle M.Sc.Author Information Jennifer J. Heisz, Ph.D., is a Canada research chair in Brain Health and Aging, an associate professor in the Department of Kinesiology at McMaster University, and the director of the NeuroFit Lab (www.neurofitlab.com). She received her Ph.D. in Neuroscience (McMaster) and completed a postdoctoral fellowship in Brain Health at the Rotman Research Institute (Toronto). Many honors recognize Dr. Heisz’s outstanding contributions to research, including the Early Researcher Award from the Ontario Government and the Petro-Canada Young Innovator Award. Maryam Marashi, B.Sc., is a second year master’s student in the Department of Kinesiology at McMaster University working in the NeuroFit Lab. Her current research examines the relationship between cardiorespiratory fitness and stress in graduate students, using heart rate variability as a biopsychological index of stress. Emma Nicholson, B.Sc., is a second year master’s student in the NeuroFit Lab at McMaster University. Her research explores the interactions between gut health and mental health and the protective effects of fitness. Michelle Ogrodnik, M.Sc., is a Ph.D. candidate in the NeuroFit Lab at McMaster University. Her current research explores how exercise affects cognition and ways that students and those with attention-related disorders may leverage this relationship. Disclosure: The authors declare no conflict of interest and do not have any financial disclosures. ACSM's Health & Fitness Journal: 9/10 2021 - Volume 25 - Issue 5 - p 13-17 doi: 10.1249/FIT.0000000000000700 Buy Metrics Abstract Apply it! By reading this article, the following key points will be reinforced: • Work with individuals exhibiting depressive symptoms in a group environment to avoid dropout. • Use sufficient rest and recovery between intense sessions for anxious clients to avoid exacerbating symptoms. • For beginner exercisers with mental health issues, start programming at lower intensity and slowly increase the intensity over time. • For executive functions, the effects of high-intensity interval training are strongest for inhibitory control, which will help clients stick with the program over the long term. Copyright © 2021 by American College of Sports Medicine.