Effects of Exercise on Explicit Memory Function: Incidental and Intentional Encoding May Depend on Exercise Timing

The Bidirectional Correlation between Fundamental Motor Skill and Moderate-to-Vigorous Physical Activities: A Systematic Review and Meta-Analysis

BACKGROUND

Physical activity in early life has positive health effects, but few children meet the physical activity recommendations. Fundamental motor skills (FMS) are related to physical activity and according to the theory, physical activity drives them in the early years and vice versa. However, no study has conducted a meta-analysis of the association between moderate-to-vigorous intensity physical activity (MVPA) and early FMS. This meta-analysis examined the bidirectional correlation between MVPA and domain-specific FMS in preschool children.

METHODS

We searched PubMed, Embase, and Cochrane Library databases for articles published up to August 2023. Cross-sectional and longitudinal studies were included if they targeted children (3-6 years old) as the study population. The association between objectively measured MVPA and FMS was evaluated.

RESULTS

We found 445 titles and abstracts. A total of ten studies (eleven datasets) and 2514 children met the inclusion criteria, including eight cross-sectional studies and three longitudinal studies. When using MVPA as the exposure, no associations were found with locomotor skills (β = 0.83, 95% CI: -0.08, 1.74, p = 0.07) and gross motor skills (β = 2.72, 95% CI: -0.28, 5.72, p = 0.08), but an association with object management skills was found (β = 0.18, 95% CI: 0.06, 0.30, p = 0.001). When MVPA was used as the outcome, no associations were observed between locomotor skills (β = 0.06, 95% CI: -0.35, 0.47, p = 0.79), but associations with object management skills (β = 0.15, 95% CI: 0.02, 0.27, p = 0.02) and gross motor skill were found (β = 0.56, 95% CI: 0.38, 0.75, p = 0.001). The sensitivity analysis showed that the results must be treated with caution.

CONCLUSION

We found that gross motor skill (exposure) was positively associated with MVPA (outcome) in preschoolers. Object management skills were positively associated with MVPA (exposure) and MVPA (outcome) in preschoolers. In contrast, MVPA as an exposure was not associated with locomotor skills and gross motor skills. The results may suggest that promoting FMS is important for preschool children's MVPA.

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.

A Review of Cognitive Changes During Acute Aerobic Exercise

A growing body of work has investigated the effects of acute, or single bouts of, aerobic exercise on cognitive function. However, review of this research has largely focused on changes following exercise, with less focus on cognitive changes during exercise. The purpose of this review is to discuss the critical characteristics of this literature to date, including: (1) what has been done, (2) what has been found, and (3) what is next. Furthermore, previous meta-analytic reviews have demonstrated there is a small positive effect on cognition when measured during exercise, with executive functions showing the largest effects. However, these reviews group executive functions together. Here we explore how inhibition, working memory and cognitive flexibility are individually impacted by factors such as exercise intensity or duration. Searches of electronic databases and reference lists from relevant studies resulted in 73 studies meeting inclusion criteria. Studies were grouped by executive and non-executive cognitive domains, intensity and duration of exercise bouts. Within the executive domain, we found that effects on working memory and cognitive flexibility remain mixed, effects on inhibition are clearer. Moderate intensity exercise improves response time, vigorous intensity impairs accuracy. Moderate to vigorous intensity improves response time across non-executive domains of attention, motor speed and information processing, with no significant effects on accuracy. Memory processes are consistently improved during exercise. Effects of exercise duration on response time and accuracy are nuanced and vary by cognitive domain. Studies typically explore durations of 45 min or less, extended exercise durations remain largely unexplored. We highlight factors to consider when assessing exercise-cognition relationships, as well as current gaps and future directions for work in this field.

Enhanced recognition of emotional images is not affected by post-exposure exercise-induced arousal

Research suggests that aerobic exercise (i.e., exercise aiming to improve cardiovascular fitness) promotes cognition, but the impact on memory specifically, is unclear. There is some evidence to suggest that as little as one session of post-learning exercise benefits memory consolidation. Furthermore, memory may be particularly facilitated by exercise when the individual is emotionally aroused while encoding stimuli. The current study tested whether exercise after exposure to neutral and emotional images improved memory consolidation of the items among university students. Ninety-nine students were randomly instructed to either exercise or not exercise after viewing a set of images that were positive, neutral, and negative in valence, and they were later tested on their memory. Although emotional images were remembered better than non-emotional images, the results suggested that exercise did not influence this effect or enhance consolidation of the items overall. Explanations and implications for these findings are discussed.