Researchers at McGill University found in a study involving 54 healthy young adults who were kept awake for 30 hours that 20 minutes of cycling exercise preserved memory performance as well as 90 minutes of sleep. The images shown to the participants were recalled again three days later.
The researchers reported that exercise cannot replace sleep but may support mental performance during short breaks. It was reported that 30- to 60-minute naps did not provide a significant restorative benefit, while the control group, which did neither exercise nor sleep, performed 22% worse than the other groups.
Why it matters
The findings indicate that the cognitive decline that emerges after prolonged wakefulness may be limited by short-term physical activity, although it cannot be eliminated entirely. This result shows that exercise may serve not only a physical but also a mental function, particularly for healthy young adults seeking an option for rest during short breaks. However, the study’s emphasis that exercise cannot replace sleep demonstrates that exercise should be regarded as a temporary support. In addition, the lack of a significant benefit from 30- to 60-minute naps raises the question of whether short naps may fail to restore performance under all conditions. The study’s findings leave open whether the same result would be observed in different age groups and under different wakefulness conditions.