Life Sciences Commons^™

Power Reserve Following Ramp-Incremental Cycling To Exhaustion: Implications For Muscle Fatigue And Function, Michael D. Hodgson

Electronic Thesis and Dissertation Repository

In ramp-incremental cycling exercise, some individuals are capable of producing power output (PO) in excess of that produced at their limit of tolerance (LoT) while others cannot. This study sought to describe the: 1) prevalence of a “power reserve” within a group of young men (n=21; mean ± SD: age 25±4 years; V̇O_2max45±8 ml•kg^-1•min^-1); and 2) muscle fatigue characteristics of those with and without a power reserve. Power reserve was determined as the difference between peak PO achieved during a ramp-incremental test to exhaustion and maximal, single-leg isokinetic dynamometer power. Pre- versus post-exercise changes …

The Feasibility Of Square-Stepping Exercise As A Universal Intervention For Older Adults With Chronic Disease To Improve Cognitive And Physical Function, Erin M. Shellington

Electronic Thesis and Dissertation Repository

Square-stepping exercise (SSE) is a cognitive training program with a physical component. An instructor demonstrates a stepping pattern across a gridded mat and participants are required to memorize and repeat the patterns on their own. In community-dwelling older adults, SSE has demonstrated some benefits on global cognitive functioning (GCF), balance, functional fitness, and social interaction.

Aims: to investigate the feasibility and efficacy of SSE in varied populations and settings to improve mobility and cognition. Populations included older adults with: knee osteoarthritis (OA), type 2 diabetes mellitus (T2DM) and self-reported cognitive complaints (sCC), and those living in long-term care (LTC) …

The Influence Of Limb And Target Vision In Target-Directed And Allocentric Pointing Movements, Joseph Manzone

Electronic Thesis and Dissertation Repository

The top-down nature of allocentric spatial representations (i.e., specifying target locations relative to other objects) is thought to render motor output via an offline mode of control. The present experiment tested this hypothesis by providing detailed trajectory analyses of allocentric and target-directed reaching tasks performed with and without concomitant limb vision. Allocentric tasks required reaches to a location defined by the relationship between a target and reference stimulus, whereas target-directed tasks required reaches directly to a target. Target-directed limb visible trials showed the most effective online trajectory amendments compared to their limb occluded counterparts and allocentric limb visible and occluded …

A Simulated Walk In Nature: Testing Predictions From The Attention Restoration Theory, Corey Crossan

Electronic Thesis and Dissertation Repository

Attention Restoration Theory (ART) predicts that top-down processing during everyday activities can cause attentional fatigue and that bottom-up processing that occurs when people experience nature will be restorative (Kaplan, 1995). The present study examined this prediction by exposing participants to three different conditions using a repeated measures design: a control condition during which participants walked on a typical treadmill, a nature/restorative condition during which participants walked on the same treadmill, experiencing a simulated nature walk, and a perturbation condition that included the same simulated nature scene but also required top-down processing during the walk. The findings supported ART predictions. As …

A Pilot Study On The Affective Responses To Watching Consecutive Episodes Of A Television Show During Aerobic Exercise Below The Ventilatory Threshold, Lauren Crutchlow

Electronic Thesis and Dissertation Repository

A quasi-experimental pilot study determined whether restricting television-watching to treadmill walking below the ventilatory threshold improved affective valence, perceived activation, enjoyment, attentional focus, and intention to bundle television-watching with exercise. Eleven inactive, young adults (21.18 + 1.47 years) in post-secondary education performed two 40-minute exercise tests, wherein aforementioned outcomes were repeatedly assessed. Participants in the experimental group (n=4) watched the first episode of a television show between exercise tests and the second episode of the same television show during the second exercise test. Analyses revealed large, non-significant multivariate intervention effects on affect and attention outcomes, a large, significant univariate intervention …

Behaviour Change Intervention Strategies To Prevent Excessive Gestational Weight Gain In Pregnant Women Using A Nutrition And Exercise Lifestyle Intervention Program (Nelip), Karishma Hosein

Electronic Thesis and Dissertation Repository

Maternal obesity and excessive gestational weight gain (EGWG) are associated with adverse maternal and fetal outcomes. To evaluate the effectiveness of different behaviour change intervention strategies, it was hypothesized that the introduction of a single behaviour change, followed by a second, would be more effective at preventing early and total EGWG in pregnant women compared to the early simultaneous introduction of both behaviour changes. Eighteen pregnant women were block randomized into one of 3 Nutrition and Exercise Lifestyle Intervention Program (NELIP) strategies (full NELIP, Nutrition followed by Exercise N+E, Exercise followed by Nutrition E+N) and were followed at weekly face-to-face …

No Evidence That Binocular Vision Enhances Online Corrections For Reaches In The Lower-Visual Field, Jennifer N. Campbell

Electronic Thesis and Dissertation Repository

Some work has proposed that an increased density of retinal ganglion cells in the superior hemiretina elicits a functional advantage for goal-directed reaches in the lower visual field (i.e., loVF). Furthermore, reaches performed with binocular stereo-cues exhibit optimized feedback-based trajectory corrections (i.e., online control). The present study examined whether the purported loVF advantage is restricted to binocular reaches implemented via a primarily online mode of control. Participants completed binocular and monocular reaches to loVF and upper-visual field (i.e., upVF) targets. Separate groups were provided vision during response planning and control (i.e., closed-loop group: CL), or during response planning only (i.e., …

Insulin Resistance And T1d: The Effect Of Exercise On Skeletal Muscle Lipid Metabolism, Michelle Dotzert

Electronic Thesis and Dissertation Repository

Insulin resistance is a characteristic of Type 2 Diabetes (T2D) and metabolic syndrome, and until recently has not been considered in the context of Type 1 Diabetes (T1D). A new classification, Double Diabetes, encompasses the presence of insulin resistance in T1D. Unfortunately, these individuals are at significantly higher risk of cardiovascular complications than those with T1D alone. In T2D, abnormal skeletal muscle lipid metabolism and the accumulation of insulin desensitizing lipid metabolites contribute the development of insulin resistance. There is some evidence to suggest this occurs in the context of T1D as well. Exercise training is an effective means to …

The Effects Of Moderate Intensity Strength Training Coupled With Blood Flow Restriction: A 12 Week Intervention, Kelly Barrett

Electronic Thesis and Dissertation Repository

Blood flow restriction training (BFRT) has been suggested to increase muscle size and strength in trained and untrained individuals when using light load intensities (30 percent 1-RM). However, there is little data to support its use when working with moderate load intensities, specifically, above 50 percent of an individual’s 1-RM. The purpose of this study was to evaluate the effects of moderate load intensity BFRT on muscle size and strength of the biceps brachii after a 12 week strength training intervention. Nine, previously strength trained, participants performed an elbow flexion exercise at 70 percent of their individualized 1-RM, twice per …

Participatory Action Research In Rural Community Sport And Recreation Management, Kyle A. Rich

Electronic Thesis and Dissertation Repository

The research conducted for this dissertation involved a participatory action research (PAR) project with the Municipality of Powassan Recreation Committee. Framed with the literature pertaining to sport and recreation development, community development, and rural community studies, the project sought to explore the perceived significance of sport and recreation, to examine the processes of sport and recreation management, as well as to inform changes to current management and policy making practices within the rural community context. Further, this project sought to identify strengths and challenges of PAR as well as to explore the processes through which researchers can work with community …

Protocol-Dependence Of Middle Cerebral Artery Dilation To Modest Hypercapnia., Baraa K Al-Khazraji, Sagar Buch, Mason Kadem, Brad J Matushewski, Kambiz Norozi, Ravi S Menon, J Kevin Shoemaker

Kinesiology Publications

There is a need for improved understanding of how different cerebrovascular reactivity (CVR) protocols affect vascular cross-sectional area (CSA) to reduce error in CVR calculations when measures of vascular CSA are not feasible. In human participants, we delivered ∼±4 mm Hg end-tidal partial pressure of CO2 (PETCO2) relative to baseline through controlled delivery, and measured changes in middle cerebral artery (MCA) CSA (7 Tesla magnetic resonance imaging (MRI)), blood velocity (transcranial Doppler and Phase contrast MRI), and calculated CVR based on a 3-minute steady-state (+4 mm Hg PETCO2) and a ramp (-3 to +4 mm Hg of PETCO2). We observed …

Motor Unit Firing In The Human Anconeus During High Intensity Eccentric Contractions Of Elbow Extensors, Christopher W. Stolworthy

Electronic Thesis and Dissertation Repository

PURPOSE: To track single motor units through both isometric and eccentric elbow extensor contractions, at near maximal contraction intensity, and compare firing rates between contraction modes at an absolute torque. METHODS: Bipolar fine-wire electrodes were inserted into the anconeus in order to record motor unit firing behaviour during sets of high torque isometric and eccentric contractions. Contractions were performed on an isokinetic dynamometer at a pre-determined speed of 10°/s, through 60° total range of elbow joint motion, and at 50, 75 or 100% MVC. RESULTS: Mean motor unit firing rates were lower during eccentric contractions across all intensities (p < 0.05), however surface EMG of the triceps brachii did not comprehensively follow the same pattern. CONCLUSION: …