Cardiovascular Effects of Acute Exercise Post-Stroke
Condition: Stroke, Cardiovascular
MeSH terms: Stroke; Myocardial Infarction
Study type: Interventional

Summary: 
      There is an urgent need to reduce the impact of stroke by promoting optimal rehabilitation
      strategies that decrease the risk of stroke. Improving cardiovascular health following a
      stroke is a key rehabilitation strategy that has the potential to reduce the risk of a
      recurrent event.

      Adverse cardiovascular events, including stroke, are often due to chronic atherosclerosis,
      which shows as increased arterial stiffness. Elevated arterial stiffness is prevalent in
      individuals with cardiovascular disease, is associated with markers of silent cerebrovascular
      disease and is a new marker for predicting cardiovascular risk. Cardiopulmonary exercise
      tests (CPETs) are used to assess cardiorespiratory fitness. Novel CPET protocols have emerged
      for stroke, enabling safe and valid measurements of cardiorespiratory fitness. Cardiovascular
      exercise, typically performed through moderate-intensity continuous exercise (MICE), can
      improve function and fitness in individuals living with stroke and lower the risk of
      recurrent stroke. Recently, high-intensity interval exercise (HIIE) has emerged as a
      potentially potent stimulus that may also lead to improvements in function and fitness. While
      HIIE has shown benefits in clinical and non-clinical populations, only a few small,
      preliminary studies have examined the effects of HIIE in individuals living with stroke, and
      most have primarily focused on examining the effects of HIIE on function and gait. No study
      has examined and compared the acute effects of a CPET, MICE and HIIE on arterial stiffness in
      stroke. This study will (1) examine the acute effects of a single session of this HIIE
      protocol compared to a CPET and a single session of MICE on arterial stiffness among
      individuals with chronic stroke, and (2) the feasibility of a high-intensity interval
      training exercise protocol previously found to be tolerable and effective in attaining high
      levels of exercise intensity in in these individuals.
    

Detailed description: 
      Stroke is the leading cause of adult disability and the fourth leading cause of death in
      Canada, with an annual cost to the economy of $3.6 billion. There is an urgent need to reduce
      the impact of stroke by promoting optimal rehabilitation strategies that decrease the risk of
      stroke. Improving cardiovascular health following a stroke is a key rehabilitation strategy
      that has the potential to reduce the risk of a recurrent event. Adverse cardiovascular
      events, including stroke, are often due to chronic atherosclerosis. Amplified arterial
      stiffness is a sign of atherosclerosis which increases arterial wall stress and reduces
      coronary perfusion. Elevated arterial stiffness is prevalent in individuals with
      cardiovascular disease, is associated with markers of silent cerebrovascular disease and is a
      new marker for predicting cardiovascular risk. Cardiopulmonary exercise tests (CPETs) are the
      gold standard for assessing cardiorespiratory fitness. In stroke, impairments in physical
      function may be present and limit individuals' ability to perform a CPET on traditional modes
      such as a cycle ergometer or treadmill. Thus, novel CPET protocols have been developed to
      allow individuals with stroke perform a fitness test safely and effectively. Cardiovascular
      exercise, typically performed through moderate-intensity continuous exercise (MICE), can
      improve function and fitness in individuals living with stroke and lower the risk of
      recurrent stroke. Recently, high-intensity interval exercise (HIIE) has emerged as a
      potentially potent stimulus that may also lead to improvements in function and fitness. HIIE
      combines short bursts of high-intensity cardiovascular exercise with periods of rest or
      recovery, and allows individuals to achieve higher intensities of cardiovascular exercise
      that do not need to be maintained for a long period of time like MICE. In this way, HIIE has
      the potential to be an additional exercise strategy to enhance cardiovascular health
      post-stroke. While HIIE has shown benefits in clinical and non-clinical populations, only a
      few small, preliminary studies have examined the effects of HIIE in individuals living with
      stroke, and most have primarily focused on examining the effects of HIIE on function and
      gait.

      While the chronic effects of exercise on arterial stiffness have been examined in stroke, no
      study has examined the acute effects of a CPET, MICE, or HIIE. Different exercise stimuli may
      elicit variable short-term influences on arterial stiffness in individuals who have had a
      stroke, but this has not been previously examined. The feasibility of HIIE for individuals
      with a broader range of functional abilities after stroke is also not well established.

      This study will (1) compare the acute effects of a HIIE session to a CPET and a session of
      MICE on arterial stiffness and (2) examine the feasibility of a HIIE protocol in individuals
      with a broad range of abilities after stroke. The investigators anticipate that (1) arterial
      stiffness will be elevated to a greater degree immediately following HIIE compared to the
      CPET and MICE, and will remain elevated following 15 minutes post-exercise, and (2) both HIIE
      and MICE protocols will be safe and feasible for individuals with stroke (no occurrence of
      adverse events), however the HIIE protocol will allow participants to obtain and be able to
      sustain a higher level of exercise intensity, and therefore a higher heart rate, compared to
      MICE. Understanding the time course of changes in arterial stiffness following acute exercise
      may provide insight into vascular responses of HIIE and thus potential underlying
      physiological mechanisms of post-stroke exercise.
    

Intervention name(s): Cardiopulmonary exercise test; Moderate-intensity continuous exercise; High-intensity interval exercise
Intervention type(s): Other; Other; Other
Intervention description(s): Participants will perform a graded cardiopulmonary exercise test to asses their cardiorespiratory fitness. It will also provide a peak exercise stimulus to examine acute changes in arterial stiffness, and to prescribe both moderate intensity continuous exercise and high intensity interval exercise.; Participants will perform a 30-minute session of moderate-intensity continuous exercise.; 1 week later, participants will perform a 19-minute session of high-intensity interval exercise.
Intervention model: Single Group Assignment
Intervention model description: This will be a single group prospective study.
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: acute exercise; High-intensity interval exercise; feasibility; arterial stiffness