Sleep deprivation reliably impairs memory, but researchers at Concordia University found a practical workaround. In a randomized study of 88 healthy young adults, one 30-minute evening cycling session at moderate intensity completely offset the memory deficits caused by a night of sleep restriction (4.5 hours). Participants who exercised before a short night performed just as well on a face-name recall test the next morning as those who slept a full 8.5 hours. The key mechanism appears to be slow-wave sleep: exercise increased the proportion of deep sleep, and that increase statistically mediated the memory benefit. The finding suggests that even a single workout can act as a physiological buffer against the cognitive costs of insufficient sleep, with deep sleep as the critical bridge.
