EXPRESS: Effects of Acute Exercise Intensity on Source Episodic Memory and Metamemory Accuracy

The Relationship Between Exercise, Cathepsin B, and Cognitive Functions: Systematic Review

Exercise has been shown repeatedly to improve cognitive functions. Many investigators have reported that peripheral signal molecules play an important role in regulating exercise-induced cognitive improvement. In this review we aimed to evaluate and clarify the literature to date that has focused on the relationship between Cathepsin B, cognitive functions, and exercise. We conducted a systematic review of the following databases from their inception until 10 April 2022: Pubmed, Web of Science, Scopus, Cochrane Library, Physiotherapy Evidence Database. The search strategy was comprised of ("cathepsin b") AND (exercise OR "physical activity") AND (cognit*). We followed three different quality appraisal tools to ensure the quality of the included studies. Eight studies assessing the effects of exercise on peripheral Cathepsin B levels and cognitive outcomes were included. Half of these studies indicated that exercise increased peripheral Cathepsin B levels and improved cognitive function. Further carefully designed studies focusing on the effects of exercise on peripheral Cathepsin B levels and cognitive performance are needed to better comprehend the underlying mechanisms of these relationships.

Effects of physical activity on visuospatial working memory in healthy individuals: A systematic review and meta-analysis

Introduction

Physical activity interventions improve cognitive performance, especially visuospatial working memory (VSWM). However, evidence on the effects of these interventions in children, adolescents, and older adults remains scant. This meta-analysis aimed to identify the effects of physical activity on VSWM improvement in healthy individuals and the best exercise intervention program to improve VSWM capacity.

Methods

We searched for randomized controlled trials (RCTs) of exercise interventions targeting VSWM in healthy individuals from Web of Science, MEDLINE, BIOSIS Previews, PubMed, China National Knowledge Infrastructure, and Wanfang Data (Chinese) databases, from inception to August 20, 2022.

Results

Among 21 articles (1,595 healthy participants), the heterogeneity test statistic was I2 = 32.3%, p = 0.053. The mean quality scores of the included articles were 6.9 points (reaction time [RT] studies) and 7.5 points (Score studies). Moreover, 28 RCTs were included (10 RT studies and 18 Score studies), and the subgroup analysis found significant effects for elderly participants, children, interventions involving a higher level of cognitive engagement, low and moderate exercise intensity, chronic exercise, exercise duration ≥60 min, and exercise period ≥90 days. Physical activity had a small but significant positive impact on VSWM in healthy individuals. Current evidence confirms the effects of physical activity on VSWM capacity only in children and seniors but not in young adults. Other age groups, including adolescents and middle-aged adults, have not been studied. Prescription of interventions involving high-level cognitive engagement, low and moderate exercise intensity, chronic exercise, exercise for >30 min per session, and exercise for more than 3 months is recommended for children and seniors.

Discussion

Future RCTs would be to fill the gap in studies on adolescents and middle-aged adults, and report detailed exercise intervention programs about different age groups.Systematic Review Registration: PROSPERO (https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022354737). INPLASY (https://doi.org/10.37766/inplasy2022.8.0053).

Effects of acute exercise on memory: Considerations of exercise intensity, post-exercise recovery period and aerobic endurance

Accumulating research demonstrates that acute exercise can enhance long-term episodic memory. However, it is unclear if there is an intensity-specific effect of acute exercise on long-term episodic memory function and whether this is influenced by the post-exercise recovery period, which was the primary objective of this experiment. Another uncertainty in the literature is whether aerobic endurance influences the interaction between exercise intensity and post-exercise recovery period on long-term episodic memory function, which was a secondary objective of this study. With exercise intensity and post-exercise recovery period occurring as within-subject factors, and fitness as a between-subject factor, 59 participants (M_age = 20 years) completed 12 primary laboratory visits. These visits included a 20-min bout of exercise (Control, Moderate, and Vigorous), followed by a recovery period (1, 5, 10, and 15 min) and then a word-list episodic memory task, involving an encoding phase and two long-term recall assessments (20-min and 24-h delayed recall). The primary finding from this experiment was that moderate and vigorous-intensity exercise improved memory function when compared to a non-exercise control. A secondary finding was that individuals with higher levels of aerobic endurance, compared to their lesser fit counterparts, had greater memory performance after exercise (moderate or vigorous) when compared to after a control condition. Additionally, individuals with higher levels of aerobic endurance, compared to their lesser fit counterparts, generally performed better on the memory task with longer post-exercise recovery periods. Future research should carefully consider these parameters when evaluating the effects of acute exercise on long-term episodic memory.