Heavier vs. Lighter Weights: Which Is Better For Women’s Brain Health?
Strength training is key for building muscle and supporting bone health. And many of us mentally feel better when we lift weights regularly. Well, this mental health connection is especially important as you age.
A new study1 published in the Journal of Affective Disorders adds to the growing body of evidence that resistance training is a powerful tool for brain health and mental well-being in aging populations. And you don't even have to lift super heavy to see positive results. Here's what you need to know.
About the study
Researchers in Brazil recruited 120 women (average age 68) and randomly assigned them to one of three groups:
- A resistance training group performing 8–12 repetitions per set (heavier weights)
- A group performing 10–15 reps per set (lighter weights)
- A non-exercise control group
Both training groups followed the same 12-week program—eight whole-body exercises, three sets each, three times per week. The difference was in the weight load and the the rep range.
Before and after the program, researchers assessed cognitive function using tests like the Montreal Cognitive Assessment (MoCA) and verbal fluency tests. They also measured mental health outcomes including depression and anxiety.
Both rep ranges boosted brain function and mood
Both resistance training groups saw significant improvements, and there was no meaningful difference between the two rep ranges. Whether you lift heavier for fewer reps or lighter for more reps, your brain and mood benefit.
Cognitive improvements:
- MoCA scores (a measure of overall cognitive function): increased by 2.9% in the 8–12 rep group and 5.2% in the 10–15 rep group
- Semantic verbal fluency: improved by 9.7% and 9.0%, respectively
- Phonological fluency: jumped by 12.3% and 12.1%
Mental health improvements:
- Depression scores: dropped by 34.2% in the heavier group and 24.4% in the lighter group
- Anxiety scores: decreased by 41.6% and 41.5%—nearly identical reductions
There were no significant changes observed in the control group.
The researchers concluded that resistance training is an effective strategy to support mental and cognitive well-being in aging populations (regardless of which rep range you choose).
Getting the most out of your workout routine
So, how do you structure your fitness routine to maximize brain benefits?
- Consistency matters most: The participants trained three times per week for 12 weeks. That regular commitment (not the specific rep range) contributed to the beneficial outcomes.
- Choose weights that feel challenging: Both groups worked to their repetition maximum, meaning they lifted loads that were genuinely difficult to complete with proper form. If your weights feel easy, it's time to take a deep breath and pick up a heavier pair. Just give it a go! You won't know how heavy you can go until you give it a try. Here's how to prevent injury while weightlifting as you age.
- Don't overthink the rep count: Whether you prefer 8–12 reps or 10–15 reps, both approaches work. Pick the one that feels sustainable for you.
- Include whole-body movements: The study used eight exercises targeting the full body. Compound movements like squats, rows, and presses are especially efficient because they train multiple muscle groups at once. Need help structuring your routine? Here's a smarter approach to strength training.
- Try a creatine supplement: Research shows that creatine supports both your muscles and your brain. Taking about 5 grams of creatine monohydrate a day helps you build even more muscle and strength from your workouts. It also supports memory and cognition (especially in older adults). This supplement pair creatine with citicoline for even more brain benefits.
The takeaway
Brain health is such a key part of healthy aging. And while staying social, playing brain games, and learning a new language are all ways to protect your brain, your exercise routine is just as important. Find a strength training modality you enjoy (whether that's weights at the gym or a group fitness class) and make it a part of your weekly routine (at least 2-3 days if possible!).