Interleaved periods of exercise do not enhance visual perceptual learning

Animal models indicate that exercise promotes visual cortex neuroplasticity; however, results from studies that have explored this effect in humans are mixed. A potential explanation for these discrepant results is the relative timing of exercise and the task used to index neuroplasticity. We hypothesized that a close temporal pairing of exercise and training on a vision task would enhance perceptual learning (a measure of neuroplasticity) compared to a non exercise control. Thirty-two participants (mean age = 31 years; range, 20-65; SD = 11.1; 50:50 sex ratio) were randomly assigned to Exercise or Non Exercise groups. The Exercise group alternated between moderate cycling along a virtual course and training on a peripheral crowding task (5 minutes each, 1 hour total intervention), and the Non Exercise group alternated between passive viewing of the virtual cycling course and the vision task. The protocol was repeated across 5 consecutive days. Both groups exhibited reduced visual crowding after 5 days of training. However, there was no difference in perceptual learning magnitude or rate between groups. Translation of the animal exercise and visual cortex neuroplasticity results to humans may depend on a range of factors, such as baseline fitness levels and the measures used to quantify neuroplasticity.