Exercise Physiology Research
My research program is primarily focused on the psychosocial barriers to the health of people with obesity. We determine how adversity in the form of either weight discrimination, or poverty, influence physical activity, food intake behaviors, and metabolic efficiency. An interdisciplinary approach is taken to investigate this topic, including observational studies, randomized interventions to reduce the impact of adversity, and experimental feeding studies that manipulate adversity. The objective of these studies is to improve the health and quality of life of people with obesity.
A secondary research interest is in establishing a causative role between specific eating patterns or foods and body weight change. For this purpose, we primarily conduct highly controlled feeding studies using objective, accurate measurement methodology in a free-living setting, with weight change as the primary outcome. The objective of these studies is to better inform public policy about food and obesity.
My research agenda is aimed at understanding the effect of vascular dysfunction, particularly as it relates to ageing and/or sex differences, on mobility. Gait is now recognized as an important activity of daily living that is closely tied to independent living and quality of life. Moreover, gait parameters such as gait speed are strong predictors of disability, disease, and mortality. While there are multiple factors that contribute to gait performance, my research centers on the influence of central and peripheral arterial function using a "healthy ageing" human model. My laboratory has demonstrated that various parameters of central arterial stiffness are significantly associated with gait speed, speed of walking while performing concurrent tasks (i.e., dual-tasking), and perceived fatigue during walking. In addition, we have provided evidence that deficiency in the ability of older adults to dilate arteries in their skeletal muscle during leg exercise is significantly associated with fatigue during walking. Based on these exciting new results, my research laboratory is diving into the physiological mechanism(s) that may explain the relation between vascular function and gait performance. The long-term goal of this research is to identify novel vascular-related targets to effectively improve gait in ageing adults and ultimately enhance quality of life.
Broadly speaking, my research interest lies in the stress response. Although acute exercise elicits the same hormones and activates the same neuroendocrine pathways that are elicited by acute psychological stress, with training, exercise can help the body maintain homeostasis and increase the body's ability to return to baseline value when faced with acute psychological stress.
A healthy system has the ability to respond to a stressor and quickly return to baseline values. The term allostasis, means literally maintaining stability (or homeostasis) through change. If the body loses its ability to return to normal physiological baseline values and stays in a state of heighted alertness or hyperarousal, disease will eventually result.
When referring to the body's dynamic ability to return to a state of rest and relaxation the term allostatic load is used. The concept of "allostatic load" was proposed to refer to the wear and tear that the body experiences due to repeated cycles of allostasis as well as the inefficient turning-on or shutting off of these responses.
Specifically, my research focuses on exercise interventions that will act as an effective stress mediator and serve as a buffer, so to speak, for chronic stress overload or allostatic overload. The mediums on independent variables that I have researched or plan to research are the following: yoga; mindfulness based movement; Tai Chi; biofeedback, and high intensity cycling.
The dependent variables in my research have been: the glucocorticoid -cortisol, the sex steroids- luteinizing hormone hormone and follicle stimulating hormone; both the time domain and frequency domains for heart rate variability; heart rate, the galvanic skin response, and the electromyogram.
I am also very interested in biofeedback for posture training, specifically a device called the upright. I believe good posture can also be effective in mediating psychological stress on a daily basis.
My research interests include the noninvasive assessment of the biomechanical properties of the muscle-tendon unit and the effects of aging on neuromuscular function and performance-based characteristics. Recent research studies involve examining age-related differences in passive stiffness, muscle size, quality, and strength characteristics between young and older men and identifying chair-rise performance abilities using maximal and rapid strength parameters in elderly adults. I am an active member of the National Strength and Conditioning Association (NSCA) and also a Certified Strength and Conditioning Specialist (CSCS).
My research explores how alterations in energy intake and exercise affect human body composition, energy expenditure, and health markers. One particular research focus is evaluating intermittent fasting programs (i.e. dietary regimens that employ repeated short-term fasts longer than a typical overnight fast) as a method to reduce energy intake and improve body composition. Additionally, I am interested in testing the utility of combining various dietary interventions with resistance training, with or without dietary supplementation. The overall goal of these areas of research is to provide new information regarding whether particular dietary components can confer unique benefits to human body composition and health.
A secondary research interest is investigating how body composition can be accurately estimated, whether through commonly used research devices (i.e. dual-energy x-ray absorptiometry and bioelectrical impedance analysis), simple approaches available to the general population, or novel methods. The goal of this research is to evaluate the usefulness of both longstanding and novel methods of body composition assessment, as well as to demonstrate the presence and importance of acute and chronic factors that impact the accuracy of estimates obtained by these devices.
Department of Kinesiology & Sport Management
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