Effect of physical exercise on hippocampal volume in adults: Systematic review and meta-analysis

Objectives. - To identify and evaluate the effect of different types of physical exercise (PE) and activity on hippocampal volume in humans. News. - The databases searched were MedLine/PubMed, Scopus, SPORTDiscus, Cochrane, Lilacs and Scielo. It was excluded during review process manuscripts that described: (i) non-experimental studies, (ii) interventions without measurement of hippocampus volume at baseline and post-intervention period, or (iii) interventions that were not compound by physical exercise. After removing duplicates, applying exclusion criteria, and checking reference lists, 13 studies were added to this review. The random effect model was used to the meta-analysis of hippocampus volume. Moderate-intensity continuous training (MICT) was the most common PE adopted among the interventions, with most of them resulting in augmented hippocampus volume. Interventions based on concurrent training (resistance training + MICT) resulted in increase at same outcome in all cases, even though the target population was different. Regarding to meta-analysis, MICT [0.34 (0.10-0.58), P = 0.006] and resistance training (RT) [0.49 (0.09-0.89), P = 0.011] were associated with increased hippocampus volume. The heterogeneity was low in both MICT (I-2 = 12.9%) and RT (I-2 = 0.0%) interventions. Conclusion. - The results suggest that MICT, RT and CT could potentially augment hippocampus volume, being its practice encouraged to both prevent and treat individuals with neurodegenerative disease as Alzheimer. (C) 2018 Elsevier Masson SAS. All rights reserved.