Key takeaways

• The best-supported exercise for stimulating the birth and survival of new brain cells (adult neurogenesis), especially in the hippocampus, is moderate, sustained aerobic activity such as brisk walking, jogging, cycling, or swimming.
• About 150–300 minutes per week of moderate cardio or 75–150 minutes of vigorous cardio is a practical target for most adults, ideally spread across 3–5 days.
• Physiological drivers include increased brain-derived neurotrophic factor (BDNF), improved blood flow and vascular health, reduced inflammation and stress signaling, and favorable changes in brain structure and function.
• Interval training and resistance work add extra benefits, but a consistent aerobic base appears most reliable for hippocampal health.

What “growing new brain cells” really means

In adults, new neurons can form in specific brain regions, most notably the dentate gyrus of the hippocampus—a structure essential for memory, learning, and emotional regulation. While the extent of adult neurogenesis in humans is still debated, a broad body of animal research and human evidence shows that regular aerobic exercise improves hippocampal function, increases key growth factors, and can enlarge hippocampal volume over time.

In practice, that translates to better memory performance, enhanced mood, and greater cognitive resilience with age.

Why aerobic exercise stands out

Neuroscientists often highlight steady-state cardio as the most dependable stimulus for neurogenesis-related pathways. Here’s why:

• BDNF boost: Aerobic exercise elevates brain-derived neurotrophic factor, a molecule that helps neurons grow, connect, and survive.
• Better blood flow: Sustained movement increases cerebral blood flow and promotes new capillary growth, improving nutrient and oxygen delivery to brain tissue.
• Metabolic signaling: Exercise-induced factors like IGF-1 and lactate act as signals that support synaptic plasticity and neuron health.
• Inflammation and stress: Regular cardio dampens chronic inflammation and helps regulate cortisol, both of which can otherwise impair neurogenesis.
• Structural changes: Longitudinal studies in older adults link aerobic training with increased hippocampal volume and improved memory performance.

How much, how hard, and how often

For most people, the sweet spot is consistent, moderate cardio with a sprinkling of higher-intensity work:

• Weekly volume: 150–300 minutes of moderate-intensity aerobic exercise (e.g., brisk walking where you can talk but not sing) or 75–150 minutes of vigorous activity (e.g., running, fast cycling).
• Session length: 20–45 minutes per session, 3–5 days per week.
• Intensity: Aim for a “7 out of 10” effort on moderate days. You should feel warm, slightly breathless, but in control.
• Progression: Increase time or intensity by roughly 5–10% per week to minimize injury risk.

A simple 8-week starter plan

Pick one or two modalities you enjoy (brisk walking, jogging, cycling, swimming, rowing, dancing). Enjoyment drives consistency.

1. Weeks 1–2: 3 days/week, 20–25 minutes moderate cardio + 2 optional easy walks (10–20 minutes).
2. Weeks 3–4: 3–4 days/week, 25–30 minutes moderate cardio. Add 3–5 short pickups (30–60 seconds a bit faster) once per week.
3. Weeks 5–6: 4 days/week, 30–35 minutes moderate cardio. One day may be intervals: 6–8 x 1 minute faster with 2 minutes easy between.
4. Weeks 7–8: 4–5 days/week, 30–40 minutes moderate cardio. Keep one interval day; the rest steady.

Optional: 2 short resistance sessions per week (20–30 minutes, full-body), which support overall brain and metabolic health.

Beyond cardio: what helps, what complements

• Resistance training: Improves insulin sensitivity, increases IGF-1, and supports cognitive health. Combine with cardio for best results.
• Skill-based activities: Dancing, tennis, or learning a new sport blend aerobic effort with coordination and novelty—both beneficial for brain plasticity.
• Intervals vs steady state: Intervals efficiently raise fitness and BDNF in some studies, but a steady aerobic base remains the most consistent “neurogenesis-friendly” stimulus.

Lifestyle levers that amplify the effect

• Sleep: Aim for 7–9 hours. Sleep consolidates learning and supports neuron survival.
• Nutrition: Favor whole foods, omega-3 fats (e.g., oily fish), polyphenol-rich plants (berries, leafy greens), and adequate protein to support recovery.
• Stress management: Mindfulness, breathing, or yoga can curb chronic cortisol, preserving hippocampal health.
• Sunlight and time outdoors: Natural light supports circadian rhythms; green spaces may enhance mood and exercise adherence.

Safety first

• If you’re new to exercise, have cardiovascular/metabolic conditions, are pregnant, or take medications that affect heart rate or blood pressure, consult a healthcare professional before starting.
• Warm up for 5–10 minutes and cool down for 5 minutes to reduce injury risk and post-exercise dizziness.
• Use the “talk test” for moderate effort: you can speak in phrases but not sing comfortably.
• Adjust for pain; sharp or persistent pain is a signal to stop and assess.

Frequently asked questions

Is running required?

No. Brisk walking, cycling, swimming, rowing, or low-impact cardio can deliver similar brain benefits if you reach moderate intensity and stay consistent.

How soon will I notice changes?

Mood and energy can improve within days to weeks. Structural brain changes and memory gains typically require months of steady training.

Can I overdo it?

Yes. Excessive high-intensity training without recovery can elevate stress hormones and impair sleep. Balance harder days with easier ones.

What about “brain games”?

They can sharpen specific skills, but the global brain-health impact of aerobic exercise is more robust. Combining physical and cognitive challenge is ideal.

The bottom line

If your goal is to nurture the birth and survival of new brain cells and keep your hippocampus healthy, consistent moderate aerobic exercise is the most evidence-backed choice. Start where you are, pick activities you enjoy, and build gradually. Add a little intensity and some resistance work over time, but let steady cardio be your foundation.

References and further reading

• Erickson KI et al. Exercise training increases size of hippocampus and improves memory. PNAS (2011).
• Voss MW et al. Exercise, brain, and cognition across the life span. J Appl Physiol (2013).
• Cotman CW, Berchtold NC. Exercise: a behavioral intervention to enhance brain health and plasticity. Trends Neurosci (2002).
• Maass A et al. Vascular hippocampal plasticity after aerobic exercise in older adults. Mol Psychiatry (2015).
• WHO Guidelines on physical activity and sedentary behaviour (2020).

Note: Findings on adult human neurogenesis vary by method and study; however, exercise’s benefits for hippocampal structure, function, and cognition are consistently supported.