Medicine and Health Sciences Commons^™

Postexercise Executive Function Benefits And Cerebral Blood Flow: In The Lab And At Home, Benjamin Tari

Electronic Thesis and Dissertation Repository

A single bout of aerobic exercise improves executive function; however, the mechanism, or mechanisms, supporting this improvement remain unclear. One candidate mechanism is an exercise-mediated increase in cerebral blood flow (CBF) that enhances the efficiency of executive-related frontoparietal networks. To evaluate the link between exercise, CBF and executive function, three separate experiments were conducted. In the first study, separate 10-min sessions of moderate-to-heavy-intensity aerobic exercise, and a hypercapnic environment (i.e., 5% CO₂) were implemented. The hypercapnic condition was included because it increases CBF independent of the metabolic demands of exercise. The second study investigated whether exercise intensity-specific changes …

Resistance Training Improves White Matter Structural Connectivity In Older Adults At-Risk For Cognitive Decline, Ryu Lien

Undergraduate Student Research Internships Conference

Diabetes is a global health concern that impacts 415 million people worldwide. Individuals who are at-risk for diabetes (characterized by high blood glucose and/or being overweight) have white matter atrophy, decreased cognitive function, and an increased risk of Alzheimer’s disease (AD). Recently, resistance training (RT) has been shown to lower white matter atrophy and white matter lesion volume. However, investigating changes in white matter tracts is complex, hence previous findings remain inconclusive. Diffusion tensor imaging (DTI) serves as a highly sensitive tool that enables visualization and characterization of white matter tracts and has the potential to combat this complexity. The …

The Effect Of Type 1 Diabetes On The Metabolic Response To Exercise, Theres Tijo

Undergraduate Student Research Internships Conference

Type 1 Diabetes Mellitus (T1DM) is an autoimmune disorder that results in insufficient endogenous insulin production. Regular exercise has numerous health benefits for individuals with T1DM, however, most insulin-dependent diabetics avoid physical activity due to the fear of exercise-induced hypoglycemia (low blood glucose/BG).

The risk of hypoglycemia in this population may be partly due to lower liver glycogen stores which is a major source of blood glucose during exercise. However, the mechanism that leads to lower glycogen stores in T1DM is unknown.

The purpose of this study was to determine the effect of an acute bout of moderate-intensity aerobic exercise …

Resedent Study- Reducing Sedentary Behaviour May Slow Cognitive Decline In Older Adults With Mild Cognitive Impairment: A Pilot Study, Kirsten B. Dillon

Electronic Thesis and Dissertation Repository

Physical activity (PA) has been shown to slow down dementia. Unfortunately, older adults spend most of their day in sedentary behaviours (SB). Breaking up prolonged bouts of sitting with intermittent bouts of light intensity PA may reduce glycemic variability in the brain; potentially mitigating cognitive decline. This study investigated how interrupting SB with 10 min bouts of light intensity PA 3x a day would affect mild to moderate cognitive impairment progression (primary outcome) in older adults residing in an assisted living facility. Participants (n=25) were assigned in clusters into a two arm 10-week single site pilot randomized controlled trial. Secondary …

Performance Impact Of Different Lower-Limb Setup Positions In The Backstroke Swimming Start, Gordon E. Barkwell

Electronic Thesis and Dissertation Repository

The performance impact of different knee extension angles in the setup position for a backstroke start was evaluated using an instrumented starting surface. Ten backstroke swimmers completed maximum-effort starts in each of two setup positions: one with the knees flexed, and one with the knees extended. The start handles and touchpad were instrumented with tri-axial force plates. Activity of major hip and knee extensors was measured using surface electromyography. Body position was recorded throughout the start using two high-speed cameras. There was no difference in time to 10 m between the two conditions, indicating there is likely no advantage in …

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 …

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 …

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 …

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 …

P34. The Effects Of Standing Desks On Classroom Performance Of University Students, Siobhan Smith

Western Research Forum

Background:

It is well established that there are many health risks associated with prolonged sedentary time.¹ Unfortunately, research conducted on university students is limited but yet they experience excessive periods of sitting time during class and while studying.

Methods:

Recently, we investigated the effect of sitting, dynamic sitting, and standing desks on classroom performance of university students.² Participants performed three 3-minute classroom simulations, one for each of the three desks. The order of the desks and simulations were randomized. Each of the simulations included a different typing and memory task.

Results:

Results showed no significant difference in the …

The Neuroprotective Effects Of Endurance Training On The Aging Brain, Katelyn Norton

Electronic Thesis and Dissertation Repository

Dysregulation of autonomic control often develops with advancing age, favoring a chronic state of heightened sympathetic outflow with parasympathetic withdrawal. However, the mechanisms of this age-related autonomic impairment are not known and may relate to alterations in brain structure (e.g. cortical atrophy) and/or altered neural function, particularly in regions related to the cortical autonomic network, namely, the medial prefrontal cortex (MPFC), insula cortex (IC), and hippocampus (HC). Exercise exerts beneficial effects on brain structure and, in the case of cognition, neurologic function; however, how exercise affects regions of the brain related to autonomic function are not known. This thesis tested …

The Effects Of Fatigue On The Reactive Agility Test: Looking At The Difference Between Normal Game Play And The Hurry-Up Offense In Football Game Simulations, Kristine E. Walker

Electronic Thesis and Dissertation Repository

Purpose: The purpose of this study was to assess the effects of fatigue on performance of the Reactive Agility Test (RAT) by University Football players. This test assesses the athlete’s ability to change direction in response to a visual stimulus, somewhat like responding to the actions of an opponent in a game. Two fatiguing conditions were compared, simulations of normal game play and hurry-up offense in football. Methods: Following a warm-up and baseline RAT testing the athletes performed 10 high intensity, sprints on a specialized treadmill, with a 1:5 work to rest ratio to simulate regular game pace. This was …

Quantifying The Effect Of Age And Contraction Mode On The Force-Velocity-Power Relationship In The Knee Extensors, Justin R. Paturel

Electronic Thesis and Dissertation Repository

PURPOSE: To assess and compare the force-velocity-power relationship (F-V-P) using isotonic and isokinetic knee extensions in 11 younger (19-30y) and 11 older (69-81y) men. METHODS: The construction of the F-V-P curves were attained with each participant performing maximal, explosive knee extensions at 8 different loads (isotonic) and 8 different velocities (isokinetic) on a Cybex HUMAC NORM dynamometer. Maximal voluntary contraction (MVC or P_o), maximal shortening velocity (V_max), maximum power, optimal torque (P_opt) and velocity (V_opt) were assessed and compared. RESULTS: The older men were 43% weaker, 18% slower and ~54% less powerful …

Adjustment Of Pulmonary O2 Uptake, Muscle Deoxygenation And Metabolism During Moderate-Intensity Exercise Transitions Initiated From Low And Elevated Baseline Metabolic Rates, Joshua P. Nederveen

Electronic Thesis and Dissertation Repository

When instantaneous step-wise transitions within the moderate intensity domain are initiated from elevated metabolic rates, the rate of pulmonary oxygen uptake (V̇O_2p) adjustment is slowed, and the V̇O_2p gain (ΔV̇O_2p /ΔWR) is greater. This study sought to determine the relationship between V̇O_2p kinetics and metabolic activity and energy status during step transitions from low and elevated metabolic rates within the moderate intensity domain. Ten young men completed six double-step constant load cycling bouts, consisting of step-wise transitions from 20 W to 45% θ_L and 45% θ_L [lower step (LS)] to 90% θ_{L …}