The science of neuroplasticity—and how to make it work for you

December 5, 2025

Imagine there was a pill that could grow brain cells.

You’d take it without question, right?

Now picture we had something low-cost, widely available, and proven (by actual science) to do exactly that.

The reality is, we already do.

It’s called exercise. And it’s the most powerful tool we have—not just to help you get lean, fit, and strong—but to literally upgrade your brain.

This might sound a bit woo. But hard data from animal and human studies say otherwise.

So let’s break down why regular activity is your one-stop-shop for halting cognitive decline, boosting your mood, and helping you stay mentally sharp—for decades.

Your brain is constantly rewiring—exercise just accelerates the upgrade.

Exercise triggers the birth of new brain cells.

Scientists call it neurogenesis.

Exercise stimulates this process, primarily in the hippocampus—the brain’s hub for learning and memory.

Data in rodent studies consistently shows movement increases the neuron count in these brain regions. Brain scans in humans show strong indirect evidence: older adults who are physically fit have larger hippocampal areas coupled with better memory performance.

These effects are in part due to what some call “Miracle-Gro” for the brain: a protein called BDNF (short for Brain-Derived Neutrophic factor).

A single exercise bout is enough to boost BDNF levels.

Once activated, BDNF goes to work—protecting existing brain cells, supporting the growth of new ones, and strengthening the connections between them.

These effects are cumulative too: each exercise session delivers a certain “dose” of BDNF, the size of which builds over time.

When you move, your brain grows. It’s that simple.

Movement rewires your brain (through neuroplasticity).

The brain has an incredible capacity to adapt, rewire, and evolve.

It’s called neuroplasticity.

And there is no better trigger than movement for reshaping your brain. This is especially true for more dynamic and complex movements.

When I started Olympic lifting in my 30s, I was surprised at how mentally—not just physically—draining these sessions were.

I now realise I wasn’t just feeling the physical effects of the workout. My brain was literally rewiring itself in real time, forming new connections to coordinate new movement patterns—at speed.

Think about it. When you move your body, you’re not just contracting your muscles.

You’re also:

Boosting blood flow to your brain, delivering oxygen and key nutrients.
Releasing growth factors such as BDNF (and others like IGF-1).
Enhancing connectivity in brain regions linked to executive function and memory.

That’s why exercise isn’t just about the physical. It’s literally future-proofing for your brain.

Exercise doesn’t just grow brain cells—it upgrades them.

More brain cells are a good thing, sure.

But better cognitive function isn’t just about more neurons—it’s about the quality of the overall network.

Beyond neurogenesis, there’s mounting evidence that exercise also:

Triggers synaptogenesis (new connections within the brain)
Improves myelination (the fatty insulation around neurons, allowing faster signals)
Protects white matter integrity (the quality and organization of brain infrastructure)

These broader system upgrades together mean quicker thinking, better reaction time, sharper focus, and improved multi-tasking ability.

The translation here is you don’t get a bigger brain with movement. You get a better one instead.

Personally, this is now one of the biggest reasons I train consistently. For me, exercise is no longer just about getting fit or jacked.

It’s about protecting my brain for better performance at work, home, or anywhere I need it (which is everywhere, right?).

Physical activity is a potent shield against cognitive decline.

This is more than just “feeling sharper”.

It’s reducing your risk of what those in midlife and beyond fear the most.

When I talk to our members, they almost always say: “I want to make sure my mind is right when I’m older.” Our protocols at Rebel Health can help with that.

The evidence is clear:

A 2022 meta-analysis in the British Journal of Sports Medicine found that physically active adults had ~20% lower risk of dementia.
A 2016 Neurology study showed people with lower fitness in midlife had smaller brain volumes 20 years later.
A 2024 review in JAMA Network Open confirmed that even low to moderate physical activity slows cognitive decline.

So if you’re in your 40s, 50s, 60s, or beyond, now is the time to invest in the kinds of activities that stop your brain deteriorating and help ward off dementia.

Not only does exercise work, it’s dose-responsive too. The more you do, the bigger the boost you get.

Providing it’s the right type, that is.

Want to really give your brain a boost? Raise your heart rate.

Aerobic activity is your brain’s best friend.

Whether it’s brisk walking, running, cycling or swimming, movement that spikes your heart rate is a trigger for BDNF.

But don’t count out resistance training.

Lifting weights does far more to your physiology than you might think.

There’s growing evidence that strength training is a powerful lever for boosting executive function and attention, which may be mediated through BDNF—but also through other hormonal effects (like IGF-1) and reduced inflammation.

I notice these effects myself. After a period of consistent lifting, my mind is calmer, clearer, and I make decisions faster. It’s almost like there’s less cognitive friction.

As for what’s best for your brain, my take is it’s not “either-or”.

Most weeks, I’ll do both aerobic and strength training:

3 lifting sessions, focused on compound movements
Plus 2-3 aerobic workouts, including brisk walking + zone 2 cardio

But don’t forget the most important part of the equation here:

Consistent action with any movement over time.

Lifting weights isn’t just for muscle—it sharpens memory, focus, and decision-making too.

My personal protocol for protecting brain health.

For me, training is more than physical performance.

It’s about future-proofing my most precious asset (my mind).

Right now I’m gearing up for a marathon. But my usual weekly framework (in between races) is:

3 x strength sessions: built on compound movements using large muscle groups (squat, hinge, push, and pull). Moderate to heavy loads, 30-45 minutes max.
2 x cardio sessions: 40-60 mins of zone 2 (could be jogging, walking, rowing).
As a bonus, I’ll sneak in a short interval session or hike on the weekends, if energy allows.

And here’s why:

Cardio (including zone 2) gives the biggest (and most consistent) BDNF bang-for-your-buck.
Adding strength work gives an extra anti-inflammatory and hormonal boost (like IGF-1).
For me, blending both keeps things interesting as well as neurologically rich.

As for how I know I’m on track? My KPIs are:

Mood and sharpness after training
Sleep quality (tracked with a wearable)
Consistency over time, not perfection

Believe me, protecting your brain doesn’t need 10 hours per week.

Just a system that allows you to show up more often than not.

You don’t need hours in the gym to change your brain.

This misconception is rife within the fitness industry.

And it’s something I hear all the time—especially with members I work with at Rebel Health.

They’ve been sold the lie that only intense, sweaty workouts count.

That’s not supported by the data. In reality, what works is:

20–30 minutes of moderate aerobic activity, 3–5 times per week
At least 2 resistance sessions per week
Short bouts of movement still matter too (e.g., 10 minutes here and there)

Yep, even “movement snacks” are enough.

So if you’re not in the season of life to train hard, then just train smart instead.

You just need to show up enough to keep the system engaged.

And if you’re too tired, injured, or busy?

That’s real life.

But just because things get hectic doesn’t mean you can’t protect your brain.

You just need to adapt. A few go-to strategies I recommend to clients (and use myself) are:

Walking meetings or “walk and talk” calls
Band exercises while watching TV
Bodyweight circuits (squats, lunges, pushups) in 10-minute windows
Some tai chi, yoga, or mobility work on low energy days

Your brain doesn’t care if you do a squat or shoulder press, either. What matters most is you’re moving your body, breathing a little harder, and getting your blood flowing.

So when you’re injured, don’t stop moving altogether.

Instead, modify your approach: do lower-body resistance work if you’ve got a shoulder or arm injury, or bring in some upper-body cardio (like boxing or arm cranking) with a lower-body niggle.

Heck, even training the uninjured side of the body works—not just for brain benefits, but because the untrained side actually gets stronger (thanks to the so-called “cross-education” effect).

Momentum is FAR more important than crushing any one workout.

This won’t fix your brain. But movement will. That’s the real nootropic.

The best brain-health protocol is the one you’ll stick with.

Remember: you don’t need a perfect plan to upgrade your brain.

You just need a repeatable one.

That’s why I regularly tell our members:

Something beats nothing
Enjoyment trumps optimization
And consistency always beats intensity

Even if you can only manage a short walk after lunch or a few push-ups in your living room this week, that’s enough. For now.

Once you get started, build your routine over time.

Future-proofing your brain isn’t about taking a pill, doing a daily “brain teaser”, or some kind of subscription app.

It’s simply your body in motion—as often as you can.

Stay sharp,

— John

Want a more personalized brain-body plan?

→ Book a consult with the RHA team and let’s map out your next steps.

Disclaimer: This reflects my personal approach and data; Rebel Health Alliance is a medical practice—talk to our concierge doctors for individualized care.