Key takeaways:
Is Resistance Training Best for Brain Health?
Bottom line: When researchers compared aerobic exercise, resistance training, mind-body practices like yoga, and combined programs for their effect on cognitive function in older adults, resistance training came out on top.
Last week we covered the GPLD1 pathway - how aerobic exercise prompts your liver to release protective signals that repair your blood-brain barrier. That's a powerful mechanism, and the evidence for aerobic exercise and brain health is strong.
But a body of research has been quietly building on a different type of exercise entirely. And a comprehensive 2025 network meta-analysis just made the case for strength training impossible to ignore.
What the research found:
The analysis, published in Frontiers in Aging Neuroscience, pulled data from dozens of randomized controlled trials involving cognitively healthy older adults. Resistance training produced the strongest overall effect on global cognition, with an effect size considered moderate to large in cognitive research (where meaningful improvements are notoriously difficult to achieve).
A parallel 2025 systematic review examined actual brain imaging alongside cognitive testing. The findings: at least two resistance training sessions per week, sustained for at least six months, were associated with measurable increases in cortical thickness in two critical brain regions.
The hippocampus (your brain's primary memory formation center) and the prefrontal cortex (involved in planning, complex reasoning, and self-control). These are precisely the regions most vulnerable to aging and most associated with early cognitive decline.
Why this matters:
These weren't just improvements in test scores. These were structural changes in brain tissue, visible on MRI scans. Six months of consistent strength training literally changed the physical structure of participants' brains.
The Exact Dose Your Brain Needs
Looking for the research-backed protocol? Here's what the evidence supports.
The Science:
Building new brain cells
When your skeletal muscles contract under load, they secrete signaling proteins called myokines into your bloodstream. One well-studied myokine, irisin, crosses the blood-brain barrier and has been shown to increase new brain cell formation in the hippocampus, your brain's memory center. So when you're working out and think you're building muscle, know that your exercise and the myokine reaction is also building new cells in your brain at the same time. The work you're doing in the weight room is literally growing your hippocampus.
Improving insulin sensitivity
Resistance training also improves how your muscles respond to insulin, contributing to better metabolic health throughout your body. This matters enormously for your brain because brain insulin resistance is increasingly understood as a central mechanism in Alzheimer's disease, some researchers even call it "type 3 diabetes." When you lift weights, you're not just managing blood sugar. You're protecting your brain from one of the most well-established pathways to cognitive decline.
Getting Started
Frequency: At least two sessions per week. Some studies suggest three sessions produces greater effects, following a dose-response pattern.
Duration: Six months minimum for structural brain changes to appear on imaging. This isn't a quick fix. It's a sustained practice.
Form matters more than weight: Good form is non-negotiable. Controlled movements through a full range of motion - no jerking, no momentum, no compromising your body position to move heavier weight. Poor form not only increases injury risk, it reduces the actual muscle stimulus you're trying to create. If you can't maintain good form for 8-12 reps, the weight is too heavy. Drop it down.
If you're new to resistance training, consider working with a trainer for even just a few sessions to learn proper form on basic movements. That upfront investment pays dividends in both safety and effectiveness.
Intensity: Moderate intensity works best - approximately 50 to 70% of your maximum. In practical terms, this means lifting a weight you can complete 8 to 12 controlled repetitions with, where the final 2 to 3 reps require genuine effort.
BetterBrain Tip: You don't need a gym membership to start. Bodyweight exercises (squats, push-ups, lunges), resistance bands, or even filled water bottles work. The goal is progressive challenge over time, gradually increasing difficulty as you get stronger. Start where you are, build gradually, and prioritize consistency over perfection.
Learn more about building a sustainable strength training practice on the BetterBrain Portal.
How to Track Your Progress
So how do you know if your strength training routine is working for your brain? Here are the markers that respond:
Insulin Sensitivity: Resistance training improves how your cells respond to insulin. You can track this through fasting insulin levels and HbA1c (which shows your average blood sugar control over three months). Better insulin sensitivity is directly associated with better cognitive function.
Inflammatory Markers: Consistent strength training reduces systemic inflammation. Track hs-CRP and homocysteine to see objective evidence of this anti-inflammatory effect. Lower inflammation means better brain protection.
Metabolic Health Markers: Strength training improves multiple metabolic markers including glucose control, lipid profiles (like VLDL-C), and overall metabolic function. These improvements happen through muscle-mediated pathways that complement what aerobic exercise does.
Why this matters: These biomarkers provide concrete evidence that your training is working. Seeing these numbers improve is powerfully motivating and shows you that the effort you're putting in is producing real results.
The case for combining aerobic and resistance training:
Last week's newsletter covered how aerobic exercise works through the GPLD1 pathway - your liver releasing signals during movement that repair your blood-brain barrier. That's one powerful mechanism.
This week's research shows strength training works through entirely different pathways: muscle-derived signaling proteins (myokines), improved insulin sensitivity, and hormonal changes that protect brain structure.
These are complementary, not redundant. Research on combined programs shows that doing both produces greater cognitive benefit than either alone.
If you're currently doing aerobic exercise regularly (great - keep that GPLD1 pathway active), adding just two strength sessions per week hits the research-backed minimum for the mechanisms we covered today.
Both are rated Essential in your BetterBrain protocol. And now you know why!
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