Benefits of Physical Exercise on Working Memory Performance: A Systematic Review of Functional MRI Studies

Working memory (WM) is a mental workspace that stores and processes information. A good WM performance has been associated with enhanced cognitive functions. Recent neuroimaging studies show evidence that physical exercises cause functional alterations in specific WM-related brain regions and these neuroplastic changes are presumed to contribute to enhanced WM performance. However, the evidence was based on studies of various types of physical exercise, with each reporting different findings. Furthermore, the effect of the different types of physical exercise on the WM-related brain regions remains elusive as reports are often inconsistent. This paper presents a systematic review of functional magnetic resonance imaging (fMRI) studies that have examined the effect of physical exercise on WM performance and the underlying neural mechanism. Articles were searched in the PubMed and Scopus databases and analysed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Five articles were included, of which three reported only on closed-skill exercises and two reported on open-skill and closed-skill exercises. The main finding is that both open-skill and closed-skill exercises can improve WM performance. For open-skill exercises, the types of physical activity found to improve WM performance were tennis, basketball, badminton, ping-pong, soccer, and dodgeball. On the other hand, the close-skill exercises were running, cycling, swimming, jumping ropes, Wushu, jumping jacks, squats, and planks. However, practising yoga was not associated with improved WM performance. Functional imaging revealed that open-skill exercise evoked more significant brain activity in WM-related brain regions than closed-skill exercises. The review also offers recommendations for future works and underscores the importance of fMRI in sports science.