Exercise and Brain Neuroplasticity: Aerobic Training Research on Hippocampal Neurogenesis

Preface: A Scientific Bridge from the Lab to Taiwan’s Roads

The dogma that “brain cells only decrease, never increase, after adulthood” has been overturned by neuroscience. In the dentate gyrus of the hippocampus, the adult brain continues to generate new neurons, and exercise is one of the most powerful natural stimuli for this process. These newborn neurons participate in learning, memory, and emotional regulation. This article will analyze how exercise “grows new neurons” in the adult brain, and what this means for maintaining lifelong cognitive health.

The Discovery of Adult Neurogenesis

Classic animal studies by van Praag, Gage, and colleagues overturned the old view: neural stem cells in the dentate gyrus of adult mice continuously proliferate, differentiate into functional neurons, and integrate into circuits. The key finding was that when mice were allowed to voluntarily run on a wheel, the number of newborn neurons doubled, and these new neurons survived and participated in function. Exercise is one of the few behavioral interventions proven to significantly increase adult neurogenesis, far surpassing the effects of environmental enrichment alone, establishing exercise’s unique position in brain plasticity.

Mechanisms by Which Exercise Promotes Neurogenesis

Exercise promotes hippocampal neurogenesis through multiple pathways: increasing BDNF to support neural stem cell proliferation, survival, and integration; increasing VEGF to promote angiogenesis, providing blood flow and a supportive microenvironment for newborn neurons; elevating IGF-1; and reducing chronic stress hormones (excess cortisol suppresses neurogenesis). Together, these factors create an environment conducive to neurogenesis. Aerobic exercise is particularly effective, indicating a close link between cardiorespiratory stimulation and the release of these trophic factors.

From Animals to Humans: Cognitive and Emotional Benefits

The exercise-induced increase in hippocampal neurogenesis in animals corresponds to better spatial learning, pattern separation (the ability to distinguish similar memories), and antidepressant effects. Although it is difficult to directly count newborn neurons in humans, imaging studies show that aerobic exercise increases hippocampal volume and improves memory (e.g., Erickson 2011), and behavioral studies show that exercise improves learning, executive function, and mood. The overall chain of evidence supports the conclusion that exercise enhances human learning and memory and protects against cognitive decline and depression by promoting hippocampal plasticity.

Exercise, Neurogenesis, and Pattern Separation: More Precise Memory

One special function of newborn neurons in the hippocampus is “pattern separation”—the ability to distinguish similar but distinct memories (such as remembering two similar cycling routes without confusing them). Animal studies show that newborn neurons increased by exercise are particularly involved in pattern separation, making memories more precise and reducing confusion. This has significant implications for daily cognition: the decline of pattern separation is associated with age-related memory problems. By promoting neurogenesis, exercise strengthens this function, potentially helping to maintain clear, precise memory. This also connects to emotion—deficits in pattern separation are linked to overgeneralization in anxiety disorders (misjudging safe situations as threats), and exercise-promoted neurogenesis may therefore contribute to emotional regulation. The brain-protective benefits of exercise extend from “remembering more” to “remembering more precisely” and “greater emotional stability.”

The Golden Combination for Neuroplasticity: Exercise + Cognition + Social Interaction

The strategy for maximizing brain benefits is to combine exercise with cognitive challenges and social interaction—this “golden combination” outperforms any single element. Exercise creates the physiological environment for neuroplasticity (BDNF, blood flow, neurogenesis), cognitive challenges (learning new skills, problem-solving, exploring new environments) provide the “content” for shaping new connections, and social interaction simultaneously stimulates cognition while providing emotional support and motivation. Research shows that the combination of “exercise + enriched environment” yields greater benefits for neurogenesis and cognition than exercise alone. The practical implication for brain-protection strategies is: rather than monotonously exercising on a treadmill, choose outdoor activities that require navigation, offer variety, and involve companions—cycling new routes and group walking are ideal forms of this golden combination.

The Human Controversy over Adult Neurogenesis

The evidence that exercise promotes hippocampal neurogenesis is solid in animals, but whether “adult humans continue to have hippocampal neurogenesis” has been a subject of academic debate. In 2018, two papers in Nature and Cell Stem Cell reached opposite conclusions—one found almost no newborn neurons in adult humans, while the other found lifelong persistence. This controversy highlights the difficulty of human research: unlike animals, newborn neurons cannot be directly labeled and counted, leaving only limited postmortem tissue samples, and differences in sample processing methods may lead to opposite results. Nevertheless, human imaging studies (increased hippocampal volume), behavioral studies (memory improvement), and direct animal evidence collectively still support the conclusion that exercise promotes human hippocampal plasticity and cognition. A rational perspective: although the “absolute number of newborn neurons in adult humans” remains technically controversial, the overall evidence that exercise benefits hippocampal function and cognition is robust and not undermined by this debate.

An Interdisciplinary Perspective: Neuroplasticity Overturns the Fate of Brain Aging

Research on exercise and hippocampal neurogenesis is a milestone in neuroscience’s overturning of the “irreversible brain aging” fate. The adult brain can still produce new neurons, and exercise is the most powerful natural stimulus—this discovery has rewritten our fundamental understanding of the brain and brought hope for combating cognitive decline. The profound significance of this interdisciplinary integration (neuroscience, exercise physiology) lies in demonstrating that exercise can induce positive structural changes in the adult and even aging brain, rather than merely passively preventing degeneration. From the neurogenesis perspective, exercise promotes newborn neurons in the hippocampal dentate gyrus; from the functional perspective, newborn neurons participate in memory precision (pattern separation) and emotional regulation; from the mechanistic perspective, BDNF, VEGF, and reduced stress hormones jointly create a favorable environment. This viewpoint elevates exercise from “physical training” to “brain training,” providing concrete strategies for preventing dementia and late-life depression. It also embodies the optimistic message of neuroplasticity—the brain retains the capacity for change throughout life, and our behaviors (especially exercise) can actively shape it. Understanding this, we recognize that regular exercise is one of the most evidence-based investments in maintaining lifelong cognitive capacity and combating cognitive aging.

From Research to the Training Ground: An Action Framework for Promoting Neuroplasticity

To promote neuroplasticity through exercise, one can follow the framework of “aerobic-first—enriched environment—social connection—long-term consistency.” Aerobic-first: aerobic exercise has the strongest evidence for hippocampal neurogenesis and plasticity and is the top choice for brain protection (cycling, walking); cardiorespiratory stimulation drives the release of BDNF/VEGF. Enriched environment: the combination of “exercise + novel environment” outperforms exercise alone—exploring new routes and varied surroundings provide the “content” for shaping new neural connections, adding to the plasticity environment created by exercise; Taiwan’s diverse cycling routes offer exactly this environmental novelty. Social connection: the social interaction of group rides and walking clubs itself stimulates cognition and provides emotional support, adding to exercise’s brain-protective benefits to form the “exercise + cognition + social” golden combination. Long-term consistency: structural changes in neuroplasticity require months to a year of regular exercise; only long-term persistence yields dividends, and establishing the habit early brings the greatest benefits. The core of this framework is: rather than monotonously exercising on a treadmill, choose varied outdoor activities with companions (such as cycling exploration), allowing exercise, cognitive challenges, and social interaction to add up, comprehensively promoting hippocampal plasticity and maintaining memory precision, emotional stability, and lifelong cognitive capacity.

Local Application in Taiwan: Climate, Events, and Cultural Context

Taiwan faces the dual challenges of dementia and late-life depression, and research on exercise-promoted neurogenesis offers concrete brain-protection strategies. Aerobic exercise—especially forms that can be sustained long-term such as cycling and walking—can promote hippocampal plasticity and maintain memory and mood. It is recommended that middle-aged and older adults establish regular aerobic habits and combine them with cognitive challenges (such as exploring new routes and social interaction in group activities), because “exercise + enriched environment” outperforms either alone. Taiwan’s diverse cycling routes provide environmental novelty—riding while exploring both exercises the body and stimulates cognition, making it a dual investment in brain health.

Taiwan’s diverse cycling and walking routes offer abundant environmental novelty—exercising while exploring stimulates both the cardiorespiratory system and challenges cognition. If middle-aged and older adults can incorporate the social elements of group rides and walking clubs, they can achieve the “exercise + cognition + social” golden combination for brain protection, comprehensively promoting hippocampal plasticity and maintaining memory precision and emotional stability—the best practice for combating cognitive aging.

Frequently Asked Questions and Myth Clarification

Myth 1: Adult brain cells only decrease, never increase? This old dogma has been overturned. The hippocampus continues to generate new neurons, at least in animals. Evidence of human plasticity (volume, function) also supports the benefits of exercise.

Myth 2: Only aerobic exercise protects the brain? Aerobic exercise has the strongest evidence for hippocampal benefits, but the combination of “exercise + novel environment + social interaction” yields even greater benefits. Exploring new routes and group activities have a synergistic effect.

Myth 3: Brain-protective benefits are immediate? Structural changes from neuroplasticity require months to a year of regular exercise. Long-term consistency is required to reap the dividends.

How to Read Exercise Science Research: Developing Evidence Literacy

This article cites 4 studies from top international journals (such as Journal of Applied Physiology, Medicine & Science in Sports & Exercise, Sports Medicine, Nature, Cell series, etc.), but as a reader, cultivating “evidence literacy” can help you absorb this knowledge more rationally rather than accepting it at face value. First, distinguish study types: randomized controlled trials (RCTs) have the strongest causal inference power; observational studies (cohort, cross-sectional) can only show associations rather than causation; animal and cellular studies reveal mechanisms but require caution when translating to humans. Second, pay attention to samples and contexts: results from small samples or specific populations (such as elite athletes or specific age groups) may not apply to you; studies predominantly based on European and American populations also warrant consideration regarding applicability to Taiwanese populations. Third, value effect size rather than just looking at “statistical significance”: statistical significance does not equal a practically large enough benefit; you must ask “is this difference important in real training or health terms?” Fourth, be wary of over-extrapolation and commercialization: preliminary findings from single studies are often exaggerated into “miracle” products or methods; wait for replication and systematic reviews. Fifth, make comprehensive judgments based on the “consistency” of mechanistic, associational, and interventional evidence, rather than rejecting everything due to flaws in a single study, or accepting everything due to one striking result. Sixth, understand that “individual differences” are the norm in exercise science: the same intervention produces different responses in different people due to genetics, training background, lifestyle, and environment; studies present group averages, so when applying to yourself, be sure to observe your own actual responses and adjust accordingly. Seventh, prioritize the “fundamentals”: sleep, nutrition, regular training, and recovery—these have abundant evidence support and clear benefits, and are always worth prioritizing over various novel supplements, equipment, or methods—many seemingly sophisticated interventions have marginal benefits far smaller than getting the basics right. Exercise science is a constantly evolving field. Maintaining an open yet critical attitude, updating your understanding as evidence evolves, while respecting individual differences and valuing fundamentals, is the only way to truly translate cutting-edge research from international journals into training and health decisions that are useful, safe, and sustainable for you—rather than blindly following trends or worshipping a single authority.

Key Takeaways

Synthesizing the above interdisciplinary research and mechanistic analyses, the core points can be distilled as follows: The adult brain can still grow new neurons: aerobic exercise is one of the strongest natural stimuli. Aerobic exercise is particularly effective: cardiorespiratory exercise releases BDNF/VEGF, creating an environment for neurogenesis. Exercise + novel environment is even better: exploring new routes combined with social interaction yields synergistic cognitive benefits. Supports mood: hippocampal plasticity is also linked to antidepressant effects. Long-term consistency is required for dividends: neuroplasticity comes from regular accumulation, not overnight results. Behind these points lies the convergence of multiple fields including sleep science, immunology, genomics, neuroscience, microbiology, endocrinology, and data science—together they illustrate a core message: the benefits and adaptations of exercise are the holistic result of multiple body systems working in coordination, not something that can be captured by any single factor. Understanding this interdisciplinary integrated perspective helps us move beyond fragmented “treat the symptom, not the cause” thinking and view training, recovery, and health in a more comprehensive way. By integrating these principles into daily training and life, and dynamically adjusting based on individual circumstances, actual responses, and professional advice, we can translate cutting-edge findings from top international journals into practices that are truly feasible, safe, and sustainable in Taiwan’s climate, racing, and lifestyle context. The value of exercise science ultimately lies in helping every exerciser—whether elite or amateur, young or old—enjoy sport more intelligently, healthily, and joyfully, and achieve physical and mental growth through it.

Practical Recommendations for Taiwanese Athletes

1. The adult brain can still grow new neurons: Aerobic exercise is one of the strongest natural stimuli.
2. Aerobic exercise is particularly effective: Cardiorespiratory exercise releases BDNF/VEGF, creating an environment for neurogenesis.
3. Exercise + novel environment is even better: Exploring new routes combined with social interaction yields synergistic cognitive benefits.
4. Supports mood: Hippocampal plasticity is also linked to antidepressant effects.
5. Long-term consistency is required for dividends: Neuroplasticity comes from regular accumulation, not overnight results.

Research Citations and Further Reading

• van Praag, H., et al. (1999). Running enhances neurogenesis, learning, and long-term potentiation in mice. Nature Neuroscience, 2(3), 266–270.
• van Praag, H. (2008). Neurogenesis and exercise: past and future directions. NeuroMolecular Medicine, 10, 128–140.
• Erickson, K. I., et al. (2011). Exercise training increases size of hippocampus and improves memory. PNAS, 108(7), 3017–3022.
• Vivar, C., et al. (2013). All about running: synaptic plasticity, growth factors and adult hippocampal neurogenesis. Current Topics in Behavioral Neurosciences, 15, 189–210.

This article is a translation of exercise science knowledge. Individual physiological responses vary. Please consult professional coaches and sports medicine physicians before making any training or intervention adjustments, and proceed gradually according to your personal health status.

Related Reading

• Cognitive Benefits of Swimming: Research on Neurogenesis in the Hippocampus from Regular Swimming
• Longitudinal Study on Aerobic Exercise, Hippocampal Volume Increase, and Memory Improvement
• Benefits of Long-term Aerobic Training on Cognitive Function: Research on Hippocampal Volume and BDNF
• Exercise-Induced Neurotrophic Factors: Research on the Multi-benefits of BDNF and VEGF