The immediate impact of moderate exercise on working memory capacity

Physical Exercise (PE) is widely acknowledged for its positive impact on cognition and specifically on short-term memory. However, the precise neurophysiological mechanisms of performance improvements are unclear. We developed an MEG-compatible pedal exercises – mimicking walking – to explore PE’s impact on working memory (WM). In simultaneous MEG/EEG recordings participants carried out an N-back task with varying WM loads across blocks and either rested or walked during 2-min-breaks between blocks. PE improved target detection, heightened EEG-spindle activity. MEG ripples (80-150Hz) displayed consistent cortical distribution, with the highest ripple occurrences detected bilaterally across MEG sensors covering the medial temporal lobe (MTL) region. Ripple likelihood correlated with the N-back levels and predicted individual target detection performance. Importantly, PE increase in ripple-spindle coupling, which plays a crucial role in memory consolidation. In summary, our study shows working memory improvement with PE through enhanced ripple-spindle coupling.