Training the sleeping brain: effects of high intensity training on sleep-dependent brain plasticity in major depression
Understanding the intricate relationship between sleep, exercise, and memory encoding is crucial for optimizing cognitive function. While sleep is known to facilitate memory consolidation, the sleep and synaptic homeostasis hypothesis emphasizes its role in global synaptic downscaling post-wakefulness, crucial for preventing cognitive overload and enabling the assimilation of new information. Exercise, on the other hand, has garnered attention for its independent benefits on memory and sleep. However, the interplay between exercise, sleep, and memory encoding remains largely unexplored. In our study, we delved into this relationship by examining the effects of two evening exercise interventions on sleep patterns (tracked via actigraphy) and subsequent memory encoding. Our findings revealed a notable positive impact of high-intensity interval training (HIIT) on memory encoding. First, we observed that participants displayed enhanced early encoding of word pairs in the HIIT condition compared to the control condition. Second, we observed a significant increase in memory encoding for low-performing participants in the HIIT condition compared to the control condition. Interestingly, this enhancement persisted for at least 24 hours. Conversely, moderate-intensity exercise yielded no discernible effects on memory. There were also no changes in sleep parameters. These results underscore the potential of brief yet intense physical activity as a straightforward and effective strategy for enhancing memory encoding.
A session of exercise before bedtime could improve sleep and thus enhance memory encoding the next morning.