Defining Optimal Aerobic Exercise Parameters to Affect Complex Motor and Cognitive Outcomes after Stroke: A Systematic Review and Synthesis

Abstract

Although poststroke aerobic exercise (AE) increases markers of neuroplasticity and protects perilesional tissue, the degree to which it enhances complex motor or cognitive outcomes is unknown. Previous research suggests that timing and dosage of exercise may be important. We synthesized data from clinical and animal studies in order to determine optimal AE training parameters and recovery outcomes for future research. Using predefined criteria, we included clinical trials of stroke of any type or duration and animal studies employing any established models of stroke. Of the 5,259 titles returned, 52 articles met our criteria, measuring the effects of AE on balance, lower extremity coordination, upper limb motor skills, learning, processing speed, memory, and executive function. We found that early-initiated low-to-moderate intensity AE improved locomotor coordination in rodents. In clinical trials, AE improved balance and lower limb coordination irrespective of intervention modality or parameter. In contrast, fine upper limb recovery was relatively resistant to AE. In terms of cognitive outcomes, poststroke AE in animals improved memory and learning, except when training was too intense. However, in clinical trials, combined training protocols more consistently improved cognition. We noted a paucity of studies examining the benefits of AE on recovery beyond cessation of the intervention.

Sex differences in the effects of exercise on cognition post-stroke: Secondary analysis of a randomized controlled trial

“…Thus, it appears that interventions that use a combined approach, along with those of longer durations, may be required for larger and more diffuse improvements in cognitive function to be observed (68).…”

High- and low-intensity exercise do not improve cognitive function after stroke: A randomized controlled trial

“…Exercise may potentially have differential effects on different domains of cognitive function after stroke. In a recent systematic review of aerobic exercise training parameters on cognitive outcomes in humans with stroke, low-moderate intensity training can improve working memory, and short-term training (8-12 weeks) can improve learning, but little evidence that aerobic training alone was beneficial for executive functions (39). It is possible that aerobic training may result in greater improvement in general function associated with increased alertness and attention whereas higher order cognitive functions, such as executive functions, may require more complex interventions than aerobic training alone.…”

“…It is possible that aerobic training may result in greater improvement in general function associated with increased alertness and attention whereas higher order cognitive functions, such as executive functions, may require more complex interventions than aerobic training alone. Combination therapies or greater intensities and longer durations may be needed (39), and physical interventions such as exercise may serve as effective complements to dedicated cognitive rehabilitation programs. Future studies may elucidate the mechanisms that underlie cognitive improvements resulting from exercise training, and examine the differential effects of various modes, modalities, and types of training, such as aerobic only vs. combined aerobic and resistance training, or physical only vs. combined physical and cognitive training (40).…”

Safety of Performing a Graded Exercise Test Early after Stroke and Transient Ischemic Attack

“…Multiple clinical stroke practice guidelines recommend an early initiation of individually tailored CRF training . CRF training can improve fitness, mobility, balance, and cognitive function and moderates cardiovascular risk profile . It has beneficial effects on metabolic adaptations both in subacute (>3 months) and chronic (>6 months) stroke populations.…”