ZOE Science & Nutrition Recap: How Exercise Slows Brain Ageing

Guest: Dr. Wendy Suzuki (Neuroscientist)
Host: Jonathan Wolf (ZOE)
Release Date: February 17, 2026

Episode Overview

This episode focuses on how physical activity benefits the brain, especially as we age. Dr. Wendy Suzuki, a leading neuroscientist, discusses the science behind brain plasticity, how exercise acts as a potent brain-boosting tool, and distills actionable advice for maintaining brain health well into later life.

Key Discussion Points & Insights

1. The Ageing Brain: What Really Happens?

• Brain Shrinkage vs. Synaptic Loss
  • With age, the brain doesn’t typically lose lots of cells (neurons) but instead loses the connections (synapses) between them.
  • Quote [00:50, Dr. Suzuki]: “There are loss of synaptic connections... It’s the synapses that leave and that are damaged. And that's the most common thing that's happening with aging.”

2. Brain Plasticity: Positive & Negative

• The brain remains changeable (plastic) throughout life.
• Positive brain plasticity: Activities and experiences can physically change the brain for the better (e.g., increasing size, function).
• Negative brain plasticity: Harmful experiences or chronic stress can damage the brain and shrink areas (like PTSD).
• Example [02:22]: Musicians who practice intensely develop larger areas of their motor cortex specific to the muscles they use.

3. Are Early-Life Skills Permanent?

• Skills like musical ability, learned intensively early in life, bestow some residual benefit but are not permanent if one stops.
• Regular practice is essential for lasting effects.
• Quote [03:14, Dr. Suzuki]: “No, it doesn’t last for a lifetime… It really does have to be a regular habit that you form.”

4. Movement: The Most Powerful Brain Support

• Exercise as Brain Maintenance
  • Physical activity is the most transformative action for your brain.
  • Unlike muscles, with exercise, the brain is bathed in a “bubble bath” of neurochemicals with every movement—even a brisk walk counts.
• Immediate effects of exercise:
  • Mood boost
  • Improved focus (prefrontal cortex function)
  • Faster reaction times
• Quote [04:17, Dr. Suzuki]: “Moving your body is the most transformative thing that you can do for your brain. Every time you move your body, there's a rush of neurochemicals that gets released in your brain. And those neurochemicals is the secret for why exercise is so transformative.”

5. The Science of “Bubble Bath” Neurochemicals

• Key chemicals released include dopamine, serotonin, noradrenaline, and endorphins.
• Even short bouts (a 10-minute walk, walking stairs) can bring benefits.
• The benefits scale with frequency and duration.
• Memorable Analogy [06:19, Dr. Suzuki]: “You get a short term benefit with a single exercise bout... but the most transformative thing happens when you don’t just do a one off. Regular exercise is going to make your hippocampus big and fat and fluffy—and that’s what you want!”

6. Neurogenesis: Growing New Brain Cells

• The hippocampus, vital for memory, actually grows with exercise due to the action of “brain-derived neurotrophic factor” (BDNF).
• Even minimal exercise leads to some new brain cell growth, but more regular activity maximizes this benefit.
• Quote [07:37, Dr. Suzuki]: “With exercise, I like to think of a watering can of growth factor that goes up and down the hippocampus every time I'm working out.”

7. What Kind of Exercise? How Much?

• You don’t have to run marathons!
  • “Power walking works just fine for mood.” [08:24, Dr. Suzuki]
• Any activity raising the heart rate (aerobic) provides significant benefit: walking, dancing, gardening, or even briskly strolling through a museum.
• Exercise has both immediate and long-term cognitive effects.
• Tip [09:51]: “Every step counts... the secret is not just more—make it fun! Because if it's not enjoyable, you're not gonna do it.”

8. How Much is Enough? (Specifics from Research)

• Dr. Suzuki’s research: Even in people starting from almost no exercise (less than 20min/week), simply doing aerobic exercise three times a week (45 minutes each, e.g., a spin class) for three months led to:
  • Improved mood
  • Better prefrontal cortex function
  • Enhanced memory
• For more active people, increasing frequency brought additional gains; every session mattered.
• Quote [11:49, Dr. Suzuki]: “They ended up doing... 2.6 times a week on average. This group did 45 minutes each... and got these brain plasticity changes.”

Notable Quotes & Memorable Moments

• On regularity vs. one-off efforts:
  • Dr. Suzuki [03:14]: “It really does have to be a regular habit that you form.”
• Motivation to move:
  • Dr. Suzuki [07:37]: “My nerdy motivation to work out in the morning is I want that watering can of growth factor going into my hippocampus and growing as many brand new brain cells because those brain cells mean my memory is going to be better and my hippocampus is going to be bigger and fatter and fluffier.”
• On making movement enjoyable:
  • Dr. Suzuki [10:10]: “Make it fun. Because if it's not fun and enjoyable, you're not gonna do it.”
• All movement counts:
  • Dr. Suzuki [09:51]: “Every step counts, every step counts.”

Key Timestamps

• 00:50: How ageing impacts brain synapses, not cell count
• 02:19: Scientific evidence for brain plasticity; musicians’ brains
• 03:14: Skill retention needs regular upkeep
• 04:17: Neurochemicals and immediate exercise benefits
• 07:37: “Watering can” of growth factor and neurogenesis motivation
• 08:24: Any aerobic movement suffices; power walking for mood
• 09:51: All steps count; importance of enjoyment
• 11:06: How much exercise? Dr. Suzuki’s prescriptions from research
• 11:49: Study results: tangible cognitive gains from ~3x/week, 45min sessions

Actionable Takeaways

• Do any movement that raises your heart rate; it needn’t be intense or prolonged.
• Make movement enjoyable and habitual—consistency trumps perfection.
• It’s never too late or too little to start reaping cognitive benefits—every step, every drop of sweat counts.

This episode distills neuroscience into everyday wisdom: move regularly, make it fun, and your brain will thank you at every stage of life.