Neuroplasticity of Brain Networks Through Exercise: A Narrative Review About Effect of Types, Intensities, and Durations.

(1) Background: Recent decades have seen growing interest in neuroplasticity and the activity-dependent mechanisms that allow Brain Networks to adapt functionally. Among the various stimuli, physical exercise has emerged as a key modulator of brain plasticity. This narrative review aims to synthesize evidence on the structural and functional effects of physical exercise on the brain in healthy individuals aged 18-80 years. Exercise modalities were categorized into Cardiovascular, Strength, and Mixed Training. Each was further classified by intensity (Light-to-Moderate vs. Vigorous) and duration (Short- vs. Long-Term). A total of 25 interventions were analyzed to evaluate how these variables influence Brain Networks. Findings indicate that exercise type, intensity, and duration collectively modulate neuroplastic responses. Notably, physical training induces structural and functional changes in major Brain Networks, including the Default Mode Network, Salience Network, Central Executive Network, Visuospatial Network, Sensorimotor Network, and Language and Auditory Networks. These results underscore the potential of physical exercise as an effective non-pharmacological strategy to enhance brain health and plasticity across the adult lifespan. This narrative review aims to highlight the effects of physical exercise in changing the brain either functionally or structurally. Moreover, the most relevant exercise training modalities that may improve/change neural networks in healthy populations (18-80 years) were discussed. (2) Methods: Three different types of exercise were considered: (i) Cardiovascular, (ii) Strength, and (iii) Mixed Exercise. For each of them, two levels of intensity (Light-to-Moderate and Vigorous) and two durations (Short-Term and Long-Term Effects) were included. By analyzing 25 interventions, indications about the effects on the brain considering the three factors (type of exercises, intensities, and durations) were provided. (3) Results: The findings suggest that the type of exercises, intensities, and durations could to lead neural modification over time. Specifically, exercise intervention contributes to both structural and functional changes in brain regions located in key Brain Networks, including the Default Mode Network, Salience Network, Central Executive Network, Visuospatial Network, Sensorimotor Network, and Language and Auditory Networks. (4) Conclusions: In conclusion, the evidence presented herein underscores the beneficial effects of physical exercise on the structural and functional integrity of the brain, highlighting its importance as a non-pharmacological intervention to improve brain plasticity.