A cerebrovascular accident (CVA), or stroke, occurs in two primary forms: ischemic, when a blocked artery deprives brain tissue of oxygen, and hemorrhagic, when a blood vessel ruptures and causes bleeding within or around the brain.
Recognizing the warning signs quickly can dramatically influence outcomes. Remember BE FAST: Balance changes, Eye changes, Face drooping, Arm weakness, Speech difficulty, Time to act. When it comes to a stroke, every minute matters.
Why the side of injury matters
A left-sided CVA typically produces right-sided weakness and may affect speech and language, including aphasia. A right-sided CVA typically produces left-sided weakness and may also cause left-sided neglect, which is a reduced awareness of the left side of the body or surrounding environment.
Once medically stable, recovery becomes a multidisciplinary process. Physical, occupational, and speech therapy work together to restore function and retrain the communication between the brain and body that was disrupted by the stroke.
The brain adapts like a muscle does
The nervous system responds to training remarkably quickly. Neural adaptations from resistance training can begin within the first several weeks, well before substantial muscle hypertrophy occurs (Haft & Triplett, 2021). This ability to adapt is particularly important after stroke, when the nervous system can respond to repeated, appropriately dosed movement and strength training through neuroplasticity (Sun & Zehr, 2019).
A 2019 study found that progressive resistance training above 70% of maximal strength decreased spasticity while improving strength on the affected side with a large effect size (0.98). Resistance training also stimulates brain-derived neurotrophic factor (BDNF), a molecule involved in nervous-system growth, learning, and adaptation (Herold et al., 2019).
One of the most valuable tools in stroke rehabilitation is cross-education: training the unaffected side to help improve strength on the affected side through shared neural pathways. A meta-analysis of 96 studies found an average 29% strength gain in the untrained side in stroke populations, compared with approximately 18% in able-bodied adults following similar training (Sun & Zehr, 2019). In one study, six weeks of ankle training produced a 34% strength increase in the trained leg and a 31% increase in the untrained leg.
Why power, not just strength, is the real target
Muscle power, which is the ability to produce force quickly, declines more rapidly with age than muscle mass or maximal strength and is more strongly associated with mortality and functional limitations than either alone (Alcazar et al., 2020). After a stroke, this becomes especially important. Hemiparesis slows walking speed and can double the physiological energy cost of walking (Lee & Stone, 2020), while even a 0.2 m/s improvement in gait speed has been associated with a 38% reduction in the odds of inpatient and personal care needs (Studenski et al., 2007). Slower gait speed and lower muscular strength are also strongly associated with poorer cognitive function in older adults.
The body and brain adapt to the demands placed upon them. Stroke rehabilitation therefore provides a valuable opportunity to progressively rebuild not only strength, but also the ability to produce force efficiently and quickly. Applying strength-and-conditioning principles alongside traditional physical therapy can help restore the physical qualities required for walking, balance, independence, and quality of life.