Recovering from a Stroke: The Role of Exercise

An estimated 7 million American adults are living with a stroke.¹ It is projected that an additional 4 million will have a stroke by 2030, which is almost a 25% increase in prevalence from 2010.² Unfortunately, stroke remains a leading cause of long-term disability in the United States.¹ Consequently, stroke survivors are often deconditioned and predisposed to a sedentary lifestyle that adversely impacts performance of activities of daily living, increases the risk for falls, and may contribute to a heightened risk for recurrent stroke and other cardiovascular (CV) diseases. These staggering statistics highlight the critical need to identify effective approaches to improve the quality of life of stroke patients. In particular, regular exercise (defined as physical activity that is planned, structured, and repetitive for the purpose of conditioning any part of the body) or physical activity (defined as any bodily movement produced by skeletal muscles that results in energy expenditure beyond resting expenditure) is one such approach, reflected by the inverse relationship between CV health and physical activity.³ Unfortunately, most healthcare professionals have limited experience and guidance in exercise programming for this diverse and escalating patient population.

In this paper, Billinger and colleagues provide an up-to-date guide for practitioners to gain a better understanding of the benefits of physical activity, including recommendations for prescribing exercise for stroke survivors across all stages of recovery.⁴ Initially, the committee describes in detail the functional and physiological consequences of a stroke. Notably there is a reduced ability to perform daily tasks and self-care, and after 6-12 months post-stroke there is a substantial decrease in cardiorespiratory fitness, muscle wasting, and an increase in intramuscular fat. There is also a switch from slow twitch towards fast twitch “fatigable” muscle fibers, increase in pro-inflammatory markers, abnormal glucose and insulin metabolism, impaired autonomic control, and respiratory dysfunction. Ultimately this increases the energy costs of walking and premature fatigue. Unfortunately, these post-stroke---related co-conditions likely reflect a response to the chronic sedentary lifestyle that is evident in stroke patients. Importantly, despite the physical limitations, many of these stroke survivors have the ability to undertake higher levels of physical activity but choose not to do so.⁵ The writing group indicates that the likely reasons for limited exercise participation by stroke patients include a lack of 1) awareness that exercise is feasible or desirable, 2) access to resources to support exercise, and 3) structured exercise sessions whereby exercises could be demonstrated by a rehabilitation specialist or exercise leader.^4,6

Importantly, from the point of view of the stroke patients, and their healthcare providers, implementation of exercise after a stroke can improve CV fitness, walking ability, upper extremity muscle strength, symptoms of depression, some aspects of executive functioning and memory, and health-related quality of life. Integrating exercise into a comprehensive plan of care including diet modification, taking cholesterol-lowering medications, antihypertensive medications, and aspirin could lower the risk of a second stroke by 80%.⁷ Yet, future research should directly address this and identify whether regular physical activity and exercise in stroke survivors translate into a reduced risk for recurrent stroke and cardiac events.

Although the primary objectives of comprehensive care following stroke are to 1) reverse the deficits caused by the stroke and minimize their impact; 2) prevent, recognize, and manage secondary medical conditions, including recurrent stroke; 3) maximize independence in ability to perform activities of daily living; 4) facilitate psychological and social adaptation and coping by the patient and family; 5) optimize the resumption of prior life-roles and reintegration into the community; and 6) enhance quality of life.⁸ Prevention of secondary conditions such as subsequent stroke and other CV events also constitutes important functions for stroke care professionals. The question is how can practitioners incorporate exercise into the stroke patient’s rehabilitation? The authors provide excellent evidence that exercise can be implemented even in the acute-stroke phase. Importantly, the physical activity goals and exercise prescription for the stroke patient need to be customized to the tolerance of the patient, stage of recovery, environment, available social support, physical activity preferences, as well as their specific impairments, activity limitations, and participation restrictions. As highlighted by the committee, the first goals during the acute post-stroke rehabilitation phase are to implement physical activity/exercise aimed at preventing complications of prolonged inactivity, regaining voluntary movement, and recovering basic activities of daily living (ADLs). Thus, during acute and inpatient rehabilitation, minimizing bed rest is critical. Simple exposure to orthostatic or gravitational stress (i.e., intermittent sitting or standing) has been shown to obviate much of the deterioration in exercise tolerance that normally follows an acute hospital stay.

Once the patient is medically stable, the authors suggest that the next goal is to initiate an exercise training regimen designed to regain (or exceed) pre-stroke levels of activity as early and as much as possible. Physical and occupational therapy are initiated to improve motor recovery (i.e., gait, upper extremity, balance, and muscle strength), motor skills, efficiency in self-care, and occupational and leisure-time activities. Emphasis is on progressive task difficulty, repetition, and functional practice. It is recommended that interventions for motor recovery include CV and strengthening exercises. It is in this supportive environment that patients (with their families and caregivers) can also learn to self-monitor their exertion and track physical activity in hospital, home, or community settings. It is critical for the patient to develop the skills and confidence for eventual self-management of physical activity and an exercise training program.

The third set of goals after stroke rehabilitation is to facilitate the stroke survivor to develop and maintain an active lifestyle that meets recommended stroke physical activity and exercise guidelines for prevention of recurrent stroke and cardiac events, and to maintain or improve physical function. The type of physical activity prescribed must take into account the stroke patient’s functional limitations and co-morbidities, as well as the patient’s personal preferences, environment, and resources, and could range from an exercise program at home to an appropriate community or sport program.

The authors emphasize that before embarking on a physical conditioning regimen after stroke, all participants should undergo a complete medical history evaluation and a physical examination aimed at the identification of neurological complications, medical co-morbidities that require special consideration or constitute a contraindication to exercise, which may include a graded exercise testing with electrocardiograph. Generally, graded exercise testing after stroke should be conducted in accordance with contemporary guidelines as detailed elsewhere.⁹

When should physical activity begin after stroke? The consensus view is that physical activity should begin early after stroke. However, how early remains controversial, and there are no specific protocols to guide the frequency, intensity, time, or type of physical activity in this time frame. Results from a pilot study (AVERT) assessing the feasibility and safety of a frequent mobilization program commencing within 24 hours post-stroke show no significant difference in the amount of deaths or secondary safety measures (falls and early neurological deterioration) between the standard of care versus a very early mobilization group.¹⁰ Further evidence from the AVERT trial indicates that earlier and more intensive mobilization after stroke may fast-track return to unassisted walking and improve functional recovery.¹¹ This would suggest that early mobilization within 24 hours of acute stroke appears to be safe and feasible, and would improve functional recovery.

Specific post-stroke exercise goals outlined by the committee are shown below:

Immediately after an acute stroke

• Low-level walking, self-care activities, intermittent sitting or standing, seated activities, range of motion activities, motor challenges. At intensities that are ~ 10-20 beats/min increases in resting heart rate; rating of perceived exertion ≤11 (6-20 scale); frequency and duration as tolerated, using an interval or work: rest approach. Such activities are aimed at preventing deconditioning, hypostatic pneumonia, orthostatic intolerance, depression, and stimulating balance and coordination.

In- and Outpatient Exercise Therapy OR “Rehabilitation”

• Aerobic exercises that include large-muscle activities (e.g., walking, graded walking, stationary cycle ergometry, arm ergometry, arm-leg ergometry, functional activities seated exercises) if appropriate. At intensities that are ~40-70% oxygen uptake reserve or heart rate reserve; 55-80% heart rate max; rating of perceived exertion 11-14 (6-20 scale), for 3-5 days/week, 20-60 min/session (or multiple 10-min sessions), that includes a 5-10 min of warm-up and cool-down activities. Such activities are aimed at increasing walking speed and efficiency, improving exercise tolerance (functional capacity), increasing independence in activities of daily living, reducing motor impairment and improving cognition, and improving vascular health and inducing other cardio-protective benefits.
• Muscular Strength/Endurance activities include resistance training of upper and lower extremities, trunk using free weights, weight-bearing or partial weight-bearing activities, elastic bands, spring coils, pulleys, circuit training, and functional mobility. At intensities that correspond to 1 to 3 sets of 10-15 repetitions of 8-10 exercises involving the major muscle groups at 50-80% of 1 repetition max, for 2-3 days/week, with gradually increasing resistance over time as tolerance permits. Such activities are aimed at increasing muscle strength and endurance, increasing ability to perform leisure-time and occupational activities and activities of daily living, and reducing cardiac demands during lifting or carrying objects by increasing muscular strength.
• Flexibility should also be a focus that involves static stretching of the trunk and upper- and lower extremities. Holding each stretch for 10-30 seconds, with the stretches performed 2-3 days/week (before or after aerobic or strength training). These activities increase range of motion of involved segments, help to prevent contractures, decrease risk of injury, and increase activities of daily living.
• Neuromuscular activities such as balance and coordination activities, Tai Chi, Yoga, recreational activities (paddles/sport balls to challenge hand-eye coordination), and active-play video gaming and interactive computer games. Employ 2-3 days/week as a complement to aerobic, muscular strength/endurance training, and stretching activities. These activities improve balance, skill reacquisition, quality of life, and mobility; decrease fear of falling; and improve level of safety during activities of daily living.

Future Directions

Although the authors provided an excellent review of the current evidence supporting the incorporation of physical activity/exercise into post-stroke recovery programs,4 a considerable amount of gaps in the literature need to be addressed. As highlighted by the authors, the critical elements (i.e., number of sessions, mode of delivery, and type of follow-up and monitoring) of a successful physical activity counseling intervention have not been definitively identified. Well-designed trials are needed to clarify optimal exercise programming and long-term outcomes of physical conditioning in this patient population, including morbidity, mortality, dependence, and disability. Whether initiating exercise early after stroke can prevent the loss of bone mineral density and deterioration of bone structure commonly seen after stroke, or reduce fracture risk, is currently unknown. Another important future direction lies with the ability to translate the exercise/physical activity findings from carefully-controlled efficacy-focused trials to real world settings. Unfortunately, although physical activity is clearly recognized as a means to reduce the risk of stroke and other CV diseases, sedentary behaviors remain a persistent and significant problem, and even more so for chronic disease populations including stroke. As suggested by the authors, healthcare professionals should understand the barriers and motivators to physical activity post-stroke, and consider ways of educating stroke survivors and caregivers on the importance of CV risk reduction and helping set goals for continued participation in physical activity and exercise.

In summary, the committee provides data that clearly support the use of exercise training (both aerobic and strength training) for stroke survivors. Exercise training improves functional capacity, improves the patient’s ability to perform activities of daily living and quality of life, and reduces the risk for subsequent CV events. Healthcare professionals should develop exercise/physical activity programs to help improve the outcome of their stroke patients.