Publications by authors named "Jaimie Ward"

Importance: For walking rehabilitation after stroke, training intensity and duration are critical dosing parameters that lack optimization.

Objective: To assess the optimal training intensity (vigorous vs moderate) and minimum training duration (4, 8, or 12 weeks) needed to maximize immediate improvement in walking capacity in patients with chronic stroke.

Design, Setting, And Participants: This multicenter randomized clinical trial using an intent-to-treat analysis was conducted from January 2019 to April 2022 at rehabilitation and exercise research laboratories.

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Purpose: Physical activity within the hospital post-stroke is recommended for cardiovascular and musculoskeletal health, but no studies have examined cerebrovascular health. We hypothesized individuals who walked farther distances (FARhigh) during the acute phase of stroke recovery in a hospital setting would have a higher resting middle cerebral artery blood velocity (MCAv) and a greater cerebrovascular response (CVR) to moderate-intensity exercise at 3-months post-stroke, compared to individuals who walked shorter distances (FARlow).

Methods: At 3-month post-stroke, we recorded 90-seconds of resting baseline (BL) MCAv followed by 6-minutes of moderate-intensity exercise.

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Background: Stroke results in neurologic impairments and aerobic deconditioning that contribute to limited walking capacity which is a major barrier post-stroke. Current exercise recommendations and stroke rehabilitation guidelines recommend moderate-intensity aerobic training post-stroke. Locomotor high-intensity interval training is a promising new strategy that has shown significantly greater improvements in aerobic fitness and motor performance than moderate-intensity aerobic training in other populations.

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Article Synopsis
  • * Findings reveal that females show a faster decline in MCAv and a greater increase in flow pulsatility index (PI) compared to males, especially in specific age groups.
  • * The results suggest that understanding these sex differences is important for addressing cerebrovascular disease and highlight the need for further research in this area.
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Background The primary aim of this study was to characterize the middle cerebral artery blood velocity (MCAv) dynamic response to an acute bout of exercise in humans at 3- and 6-months poststroke. As a secondary objective, we grouped individuals according to the MCAv dynamic response to the exercise bout as responder or nonresponder. We tested whether physical activity, aerobic fitness, and exercise mean arterial blood pressure differed between groups.

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Purpose: The aim of this study was to evaluate the of cardiovascular disease (CVD) on middle cerebral blood flow velocity (MCAv) at rest and during exercise. A secondary aim was to explore the relationship between MCAv and 1) the presence of white matter lesions and 2) cognitive function.

Methods: We recruited individuals who were cognitively normal older adults.

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Liver adaptations may be critical for regular exercise and high aerobic capacity to protect against metabolic disease, but mechanisms remain unknown. Bile acids (BAs) synthesized in the liver are bioactive and can putatively modify energy metabolism. Regular exercise influences BA metabolism in rodents, but effects in humans are unknown.

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Article Synopsis
  • The study explored cerebral autoregulation in healthy humans using a new method based on Bendat nonlinear analysis techniques.
  • The findings revealed that traditional linear analysis methods inaccurately estimated key parameters, while the novel nonlinear methods provided accurate descriptions of the system dynamics.
  • By integrating both linear and nonlinear coherence, the study demonstrated a more comprehensive understanding of cerebral blood flow regulation, especially at lower frequencies.
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Background And Purpose: Exercise plays an important role in supporting overall brain health. However, the mechanisms by which exercise supports brain health are imprecisely defined. Further, brain hemodynamic changes during exercise are not clearly understood, especially in older adults.

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Blood flow regulation is impaired in people with stroke. However, the time course of change in middle cerebral artery velocity (MCAv) following repeated stroke at rest and during exercise remains unknown. In this case study, we provide novel characterization of the dynamic kinetic MCAv response profile to moderate-intensity exercise before and after repeated ischemic MCA stroke.

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Background And Purpose: Previous work demonstrates that older adults have a lower response in the middle cerebral artery velocity (MCAv) to an acute bout of moderate-intensity exercise when compared with young adults. However, no information exists regarding MCAv response to exercise after stroke. We tested whether MCAv response to an acute bout of moderate-intensity exercise differed between participants 3 months after stroke and an age- and sex-matched control group of older adults (CON).

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Androgen deprivation therapy (ADT) is a treatment used across the prostate cancer disease spectrum and works by suppressing testicular androgen production to castrate levels. Although ADT can provide survival benefits, it is also associated with increased risk for cardiovascular disease, metabolic syndrome, increased visceral fat mass, dyslipidemia, decreased arterial compliance, and diminished health-related quality of life. The Staying Strong And Healthy protocol is a telephone-delivered intervention led by a nurse coordinator to minimize the increased cardiovascular and metabolic risks associated with ADT.

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Background: Vascular health is closely related to Alzheimer's disease (AD). Vascular function measured by flow mediated dilation (FMD) or pulsatility index (PI) can be used as marker of peripheral and central vascular health but is poorly characterized in those at risk for AD.

Objective: To assess the relationship of peripheral and central vascular function with amyloid-β (Aβ) and white matter lesion burden among cognitively normal older adults.

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Despite its necessity for understanding healthy brain aging, the influence of exercise intensity on cerebrovascular kinetics is currently unknown. We, therefore characterized middle cerebral artery blood flow velocity (MCAv) kinetics associated with two exercise intensities: low and moderate. We hypothesized that increasing exercise intensity would increase the MCAv amplitude response (Amp) and that age and estimated fitness (V̇O2max) would be related to Amp.

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Blood velocity measured in the middle cerebral artery (MCA) increases with finite kinetics during moderate-intensity exercise, and the amplitude and dynamics of the response provide invaluable insights into the controlling mechanisms. The MCA response after exercise onset is well fit to an exponential model in young individuals but remains to be characterized in their older counterparts. The responsiveness of vasomotor control degrades with advancing age, especially in skeletal muscle.

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The goal of this study was to explore the association of beta-amyloid accumulation and cerebrovascular response (CVR) in cognitively normal older adults. Beta-amyloid accumulation was characterized with [18F] Florbetapir positron emission tomography scans. CVR was calculated as middle cerebral artery blood flow velocity change from rest to moderate intensity exercise.

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Background: Exercise-induced bronchoconstriction (EIB) can lead to long-term respiratory illness and even death. EIB prevalence rates are both high and variable in college athletes. Also, prevalence rates may be underestimated due to ineffective screening.

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