Our Team

Learn more about our team members below.
Principal Investigator

Kerri Winters-Stone, Ph.D., FACSM
Principal Investigator
An exercise physiologist by training, my expertise is on the use of physical activity to prevent and manage chronic disease. My studies have shown that cancer survivors can benefit from exercise that reverses treatment-related side effects and symptoms. Ultimately the goal of my work is to develop safe, targeted and effective exercise programs that translate well to community settings and clinical practice so that people can make positive lifestyle choices for better long-term health.
Senior Leadership

Carolyn Guidarelli, M.P.H., CCRP
Senior Clinical Research Associate and Lab Manager
From an early age, and due to personal family experiences with cancer, I knew I wanted to dedicate my career to making life better for patients with cancer. After completing my undergraduate degree at the University of Portland, I pursued a Master of Public Health in Epidemiology from Boston University where my studies focused on non-infectious, chronic diseases, such as cancer. Having grown up in Oregon and being an avid sports enthusiast, I jumped at the opportunity to return to the Pacific Northwest and engage in research that combines two things close to my heart: exercise and cancer. I have witnessed first-hand how therapeutic the right exercises can be, especially in the lives of those affected by cancer. I have been working in Dr. Kerri Winters-Stone’s Exercise Lab since 2012 and I am proud to be a part of a team that is leading the charge in developing evidence-based exercise programs that may one day be an integral and complimentary part of routine clinical cancer care. As the lab manager, I oversee a multitude of grant-funded trials, manage an ever-growing team, contribute to scientific development, data management and analysis, and dissemination of our findings. I stay active with my husband and our two young kids in my free time.

Jessica Sitemba, M.S.
Clinical Research Associate
Since obtaining my master's degree in exercise science in 2006, I have been blessed with the opportunity to work as a project director on multiple exercise intervention studies aimed at using exercise to improve symptoms and side effects from cancer and cancer treatment, ultimately improving quality of life for many cancer survivors. I have seen firsthand what exercise can do for this population and am thrilled to continue working on these types of studies as long as possible with the ultimate goal of implementing the classes into the community for all cancer survivors to benefit from. As a research associate, my main role is to manage the exercise interventions for multiple trials. This includes assisting in the initial design of the programs, instructor training and management, and overseeing the overall progress and conduct of the exercise classes.

Stephanie Krasnow, Ph.D.
Project Director
After earning a Ph.D. in physiology and biophysics from the University of Washington, I spent a decade at the bench studying the central nervous system pathways that disrupt appetite, metabolism, and neuroendocrine function during acute and chronic illnesses. I was trained in clinical and translational cancer research by completing a Brenden-Colson Center for Pancreatic Disease fellowship and earned a certificate in Human Investigations. My research is focused on identifying predictors of treatment-related side effects and strategies to mitigate their negative impact on clinical outcomes and quality of life in patients with cancer. As a project director, I oversee the design, conduct, and analysis of an observational study examining neuropathy and mobility deficits in patients with cancer that are treated with neurotoxic chemotherapy.

Deanne Tibbitts, Ph.D., MCR
Assistant Research Professor
I grew up in Georgia, where I earned my bachelor’s degree in genetics and cellular biology at the University of Georgia. I then moved to Portland and completed my Ph.D. in molecular and medical genetics at OHSU studying the molecular basis of leukemia and the application of targeted cancer therapeutics. I went on to complete a certificate in Human Investigations at OHSU and an NCCIH-funded clinical research fellowship in complementary and integrative health at the National University of Natural Medicine. During my fellowship, my research focused on using mind-body interventions, including trauma-informed yoga and yoga nidra, to improve emotional well-being. In the Winters-Stone Exercise Lab, my work focuses on the use of exercise and mind-body interventions to improve psychosocial outcomes and quality of life in cancer survivors.

Sydnee Stoyles, MBST, MAT
Biostatistician 2
I have always wanted a career where I could help others. After a few years in secondary education as a math teacher, I realized the classroom was not the fit I was hoping it would be. I returned to school and received my master's degree in biostatistics from OHSU’s School of Public Health in 2015. I have worked under Dr. Nathan Dieckmann at the OHSU School of Nursing since 2015. There I have been able to assist on a variety of projects including improving nursing education, fall prevention, post-partum depression, and understanding chronic pain in adolescents, as well as exercise intervention trials with the Winters-Stone lab. My work focuses on data management and analysis. I participate in creating analysis plans, preparing data, and running analyses as well as contributing to posters and manuscripts. I am grateful for the opportunity to work with Dr. Winters-Stone’s lab where I can contribute to the lab’s work on improving quality of life and well-being for cancer survivors.
Clinical Research

Christopher Chalmers, M.S.
Senior Clinical Research Assistant
I worked as a personal trainer for years, coaching a myriad of different clientele from collegiate athletes to retired veterans. After finishing my bachelor's degree, I worked in military physiology research, where our efforts were to improve the efficiency and safety of our soldiers. Subsequently, I received a master’s degree in exercise and sport science at Merrimack College where my thesis focused on the effects of seated load carriage on the soldier's physical and mental performance. Now, I am fortunate to work with an amazing team at the Winters-Stone Exercise Lab, learning, and researching how exercise plays a critical role in cancer survivorship. Cancer has affected everyone to some degree, and seeing how our work positively affects cancer survivors brings me immense fulfillment. As a research assistant, I recruit research participants, schedule and conduct data collection appointments, and ensure survey completion. I also manage the ever-evolving technology aspects of study involvement and help facilitate access and support to our participants across trials.

Ellis Hews, MUS
Senior Clinical Research Assistant
I first became interested in improving the health outcomes of older adults, especially those coping with chronic illnesses, while completing my master’s degree in urban studies with a concentration in gerontology. After spending some time conducting research with older adults at PSU’s Institute on Aging, I discovered that community-dwelling older adults need resources and programs that would enhance social well-being and improve access to healthy food and housing. I am delighted to be working with the Winters-Stone Exercise Lab because I get to witness how the interconnection of exercise and technology improves the quality of life of older adults coping with cancer. As a research assistant, I help to lead efforts with recruitment, including community outreach to our partners and providers. Outside of work, you can find me biking in a blazer or antique shopping.

Thais Denmark, Ph.D.
Senior Clinical Research Assistant
I am from Brazil and completed my Ph.D. in the science of human motor skills with a focus on physical activity and health. I completed my Ph.D. internship at Oregon Health & Science University with Dr. Kerri Winters-Stone in 2016 and 2017. I have a background in clinical research studying the effects of combined exercise (resistance and aerobic) programs on body composition and quality of life in breast cancer survivors. As a senior research assistant on Dr. Winters-Stone's exercise trials for cancer survivors and the elderly. I work on the development and delivery of exercise programs, instructor training, and overseeing the overall progress and conduct of the exercise classes. I believe that exercise can help people to get healthy and live longer and I see exercise as medicine. I am sure that the work our team does contributes to incorporating exercise as a standard of care for all cancer survivors.

Christopher Palmer, B.S.
Clinical Research Assistant II
I graduated from Linfield College in 2018 with a bachelor's degree in exercise science. After graduation, I started working in a physical therapy clinic in McMinnville, OR as my first post-graduate job. After almost three years of working there, I realized that I wanted to take on a new adventure that still helps benefit others. Having performed numerous research studies in my undergraduate work related to exercise, nutrition, weight training, and strength and conditioning, I knew that working in the Winters-Stone Exercise Lab would be a great fit for me. My family history is riddled with cancer, the most recent being my grandfather, who unfortunately passed away. I knew as a young teenager that I eventually wanted to become involved in the cancer field and the fact that I loved research during college helped bring this part of my life full circle. I joined the Winters-Stone Exercise Lab in 2021 with the hopes of gaining and advancing my knowledge of exercise and its role in chronic diseases, especially cancer. Working with this team has given me so much more insight and knowledge than I could hope for and I am thrilled to continue that and help bring fulfillment and knowledge to those in cancer survivorship. As a research assistant, I recruit research participants, schedule and conduct data collection appointments, and ensure survey completion. I also assist in the management and data conversion of wearable sensors used in various aspects of our research.

Becky Chan, B.S.
Clinical Research Assistant II
After receiving a bachelor's degree in human physiology from the University of Oregon, I quickly realized I was far more passionate about the overarching field of public health than about the clinical healthcare path I had been preparing for. That curiously led me to serve a two-year term in Peace Corps Botswana, where I was placed in the rural village of Pilikwe and worked on implementing HIV capacity-building projects at a grassroots level. Upon returning to the U.S., I looked toward research to integrate my love for scientific knowledge with the fulfillment I get from contributing to meaningful work. I am beyond thrilled to have found that perfect balance in the Winters-Stone Exercise Lab, where I get to witness the positive effects of exercise on cancer survivorship and work alongside an amazing team. As a research assistant, I recruit research participants, schedule and conduct data collection appointments, and ensure survey completion. I also assist in community outreach across our trials.

Kendra Braun, B.S.
Clinical Research Assistant II
I graduated with honors from Oregon State University in 2021 with a Bachelor of Science in nutrition. As an undergraduate, I worked in Dr. Emily Ho’s Cellular and Molecular Nutrition Lab for three years to complete my honors thesis project while also assisting with other studies that the lab conducted. Although my ultimate goal is to attend medical school, I knew through my experience at Oregon State that I wanted to continue working in research. Joining Dr. Kerri Winters-Stone’s team is an exciting opportunity for me to contribute to research that I find extremely valuable and fulfilling, knowing that cancer and other chronic diseases affect many of us at some point in our lives. As a research assistant, I recruit research participants, schedule and conduct data collection appointments, and ensure survey completion. As a former group fitness instructor, I’m excited to be a part of an exercise oncology lab. In my free time, I enjoy attending group fitness classes and trying new recipes.

Dmitriy Avramov, B.S.
Clinical Research Assistant II
I graduated from Portland State University in 2020 with a Bachelor of Science in biology. During my undergraduate years, I had the chance to volunteer and learn about underserved populations, which contributed to my interest in medicine and my desire to give back. I am currently volunteering at the OHSU emergency room and am working toward my ultimate goal of attending medical school to become an internist. Medicine relies on old and new discoveries, so having the opportunity to work in research with Dr. Kerri Winters-Stone and her team provides me with valuable experience that I will take with me into medical school. As a research assistant, I help recruit research participants, schedule and perform data collection, and ensure survey completion. I have been enjoying my time and this has been a very humbling experience. In my free time, I enjoy reading, exercising, and watching educational videos.
Students and Scholars
Graduate Students and Postdoctoral Scholars

Christopher Barnes, PT, D.P.T., Ph.D.
Postdoctoral Scholar
Chris is a physical therapist and health services researcher who specializes in improving access to physical rehabilitation for people with cancer. He earned a Doctorate of Physical Therapy at Northern Arizona University in 2016 and a Ph.D. in Rehabilitation Science from the University of Utah in 2022, and joined the Winters-Stone Exercise Lab as a postdoctoral scholar in August 2023. Professionally, he focuses on ways to provide barrier-free physical rehabilitation care for all people with cancer. In his non-work time, he enjoys playing good music for his houseplants and taking walks. Chris will be working with the PACS team to learn more about how older people with cancer think and feel about digital technology, exercise, and physical activity.
Exercise Trainers
- Ron Baglien
- Laura Carim Todd
- Melissa Woodburn
- Fernando Ramos
- Nancy Nelson
Alumni
- Kimi Daniel
- Ramyar Eslami
- Nick Winder
- Megan Skiba
- Shannon Austin
- Mary Medysky
- Pablo Herrera-Fuentes
- Cassie Boisvert
- Collin Lipps
- Jade Moon
- Ashley Lyons
- Bryan Loy
- Maddy Dunn