The researchers conducted an exhaustive search for pooled data analyses derived from randomized controlled trials. These trials compared exercise interventions to various control conditions, including alternative physical activities, placebos, or no intervention at all. Importantly, the study only included well-defined, structured, and repetitive physical activities intended to enhance both physical and mental health. It encompassed all forms, intensities, frequencies, and contexts of exercise participation, whether solitary or group-based, supervised or unsupervised.

Encompassing an extensive range of participants between the ages of 10 and 90 for depression studies, and 18 to 67 years for anxiety investigations, the research incorporated data from tens of thousands of individuals. Specifically, 800 component studies involving nearly 58,000 participants contributed to the depression analysis, while 258 studies with over 19,000 participants informed the anxiety component. This wide sampling provides a robust foundation for generalizing the results across populations, including those diagnosed with clinical conditions and those experiencing symptoms without formal diagnosis.

The meta-meta-analysis revealed that exercise exerts a medium effect size in reducing depression symptoms and a small to medium effect size for anxiety relief. The efficacy appeared especially pronounced among young adults aged 18-30 as well as women in the postpartum period. This suggests a compelling age- and gender-related interaction effect, which may inform tailored interventions designed to optimize treatment responses based on demographic considerations.

Notably, aerobic exercises emerged as the frontrunners in generating substantial improvements in depression, particularly when conducted in group settings or under professional supervision. These social factors likely augment the therapeutic impact by fostering community, support, and accountability among participants. Resistance training, mind-body modalities—including yoga, tai chi, and qigong—and mixed-format routines, also demonstrated meaningful benefits for anxiety, underscoring the value of exercise diversity in mental health protocols.

The current evidence aligns exercise interventions not merely as complementary but potentially as equivalent or superior alternatives to pharmacological and psychological therapies. Such equivalence is remarkable given the pervasive challenges associated with medication side effects, treatment adherence, and accessibility barriers inherent to conventional mental health care. Exercise, with its added physical health benefits and cost-effectiveness, offers an attractive solution that could revolutionize approaches to mental health management.

The investigators prudently note limitations that should temper interpretations. Variation across included analyses in defining exercise intensity and duration invites some caution in prescribing precise “doses” of exercise for mental health treatment. Moreover, the relative paucity of pooled data across the entire lifespan signals a need for further longitudinal studies to ascertain long-term impacts and age-specific nuances of exercise’s mental health benefits.

Despite these limitations, this meta-meta-analysis robustly underscores the potential of exercise as a frontline intervention for depression and anxiety. The pronounced effectiveness of group and supervised formats emphasizes social interaction as a critical therapeutic component, reflecting growing recognition of psychosocial factors in mental health outcomes. Consequently, mental health practitioners are encouraged to embrace personalized exercise prescriptions, carefully calibrated to individual needs, preferences, and clinical profiles.

In light of these findings, public health policy could strategically integrate exercise programs within mental health services, especially in settings where traditional access to psychological therapies or pharmaceuticals is constrained. The accessibility, affordability, and minimal adverse effects of exercise position it as an empowering tool to bridge gaps in mental health care globally.

Future research should prioritize standardized criteria for exercise parameters in mental health studies, enabling clearer comparative analyses and evidence-based guidelines. Additionally, expanding research inclusivity to cover diverse age groups, ethnicities, and comorbid conditions would enrich the evidence base and enhance applicability across heterogeneous populations.

Ultimately, this landmark synthesis offers compelling empirical validation that exercise extends well beyond physical fitness. It serves as an effective, versatile, and holistic modality for mental health improvement, with significant implications for clinical practice, public health strategies, and individual well-being. As depression and anxiety continue to impose substantial global burdens, harnessing the therapeutic potential of exercise may herald a new paradigm in mental health care.

Subject of Research: People
Article Title: Effect of exercise on depression and anxiety symptoms: systematic umbrella review with meta-meta-analysis
News Publication Date: 10-Feb-2026
Web References: http://dx.doi.org/10.1136/bjsports-2025-110301
Keywords: Physical exercise, Anxiety, Depression

Subthreshold depression, characterized by depressive symptoms that are clinically significant yet insufficient to meet full diagnostic criteria for major depressive disorder, poses a unique clinical challenge. The heterogeneity of symptom response to AE within this population underscores the necessity for biomarker identification that can forecast treatment outcomes. The amygdala, a critical brain region implicated in emotion regulation and mood disorders, presents a logical focal point for investigating such predictive markers due to its extensive connectivity within affective and cognitive neural circuits.

The study enrolled 43 participants diagnosed with StD who underwent a structured AE intervention designed to assess changes in depressive symptomatology. Pre- and post-intervention assessments were conducted using the Patient Health Questionnaire-9 (PHQ-9), a standardized clinical tool for quantifying depression severity. Participants were dichotomized into remitters and non-remitters based on their post-intervention PHQ-9 scores, enabling the examination of differential neural connectivity patterns relative to treatment efficacy.

Resting-state functional magnetic resonance imaging (rs-fMRI) served as the cornerstone of the neuroimaging methodology, capturing spontaneous brain activity and functional connectivity without the influence of task performance. By focusing on the amygdala’s connectivity with various cortical and subcortical structures, the research probed the neural substrates that might underlie symptom amelioration following AE. This approach capitalizes on the premise that intrinsic connectivity patterns can reveal latent neural circuit configurations associated with treatment responsiveness.

Analyses revealed compelling associations between baseline amygdala functional connectivity and depressive symptom outcomes post-exercise. Specifically, increased connectivity of the left amygdala with the right precuneus and bilateral middle frontal gyrus (MFG) was positively correlated with higher PHQ-9 scores after the intervention, indicating poorer symptom remission. Conversely, connectivity of the left amygdala with the left precuneus and left MFG exhibited negative correlations with symptom improvement, suggesting a nuanced relationship between neural circuit dynamics and therapeutic benefit.

Intriguingly, remitters demonstrated significantly reduced functional connectivity between the left amygdala and the left supplementary motor area (SMA) compared to non-remitters. This finding hints at the SMA’s potential role in modulating mood-related neural networks in the context of AE and points toward decreased amygdala-SMA coupling as a marker of positive treatment response. The SMA’s involvement in motor planning and cognitive control may interface with emotional regulation pathways, providing a plausible mechanistic substrate for observed effects.

Explorations of the right amygdala’s connectivity painted a slightly different picture. Enhanced connectivity between the right amygdala and regions including the left inferior parietal lobe (IPL), right middle temporal gyrus (MTG), left superior medial frontal gyrus (mSFG), and left MTG correlated with higher residual depressive symptoms post-intervention. However, these associations did not extend to symptom change metrics or group-level differences, underscoring possible lateralization effects in amygdala functional connectivity related to treatment outcomes.

The study further employed integrative analyses combining bilateral amygdala connectivity data with clinical variables, yielding robust classification accuracy (AUC = 0.93) within the sample for distinguishing remitters from non-remitters. This high predictive power underscores the practical potential of neuroimaging biomarkers in forecasting individual response to AE, a significant leap toward precision medicine paradigms in psychiatry. The ability to predict responders prior to intervention could optimize resource allocation and tailor treatment plans.

Despite the promising findings, the absence of significant group-by-time interactions in the connectivity patterns tempers the interpretation, suggesting that the observed functional connectivity differences were not dynamically altered by the AE intervention over time but rather reflected baseline neural states predictive of outcome. This nuance invites further longitudinal and interventional studies to unravel causality and temporal dynamics in neuroplasticity associated with exercise-based therapies.

The implications of these findings resonate beyond the immediate context of subthreshold depression. They highlight the intricate interplay between neurocircuitry and behavioral intervention efficacy, emphasizing the need to integrate neurobiological assessments into clinical practice. The amygdala’s connectivity profile emerges as a potential biomarker not only for predicting AE responsiveness but also for guiding adjunctive therapeutic strategies, including neuromodulation or cognitive-behavioral interventions.

While exploratory, this research marks a critical step in decoding the neural correlates of exercise-induced mood improvement. The deployment of rs-fMRI to reveal individual differences in brain connectivity furthers our understanding of depression’s neural architecture and its modulation by lifestyle factors. Future investigations expanding sample sizes and incorporating control conditions are essential to validate and extend these insights.

This novel perspective invigorates the discourse on exercise psychiatry, bridging neuroimaging advancements with clinical symptomatology. It encourages a paradigm shift towards leveraging functional brain metrics in the design and monitoring of interventions. As the mental health field grapples with treatment heterogeneity and accessibility challenges, such neurobiologically informed approaches could revolutionize care pathways, optimizing outcomes through personalized medicine.

In conclusion, the study underscores the pivotal role of amygdala-based functional connectivity in modulating depressive symptoms in response to aerobic exercise among individuals with subthreshold depression. By illuminating neural predictors of treatment response, this work paves the way for integrating neuroimaging biomarkers into clinical algorithms for depression management, promising more targeted and effective non-pharmacological interventions in mental health care.

Subject of Research: Functional connectivity of the amygdala as a neural predictor of response to aerobic exercise in subthreshold depression

Article Title: Amygdala functional connectivity and response to aerobic exercise in subthreshold depression-an exploratory fMRI study

Article References:
Huang, L., Zhang, W., Zhang, J. et al. Amygdala functional connectivity and response to aerobic exercise in subthreshold depression-an exploratory fMRI study. BMC Psychiatry 25, 1078 (2025). https://doi.org/10.1186/s12888-025-07535-3

Image Credits: AI Generated

DOI: 10.1186/s12888-025-07535-3 (Published 11 November 2025)