A brain exercise is any activity done deliberately to strengthen a mental skill — from a crossword to a working-memory app to learning a language. The catch is that most of them make you better at the exercise itself without doing much for your everyday thinking, and only a handful have solid evidence of carrying over to real-world cognition.
Key Takeaways
- Most "brain exercises" produce near transfer — you improve at the trained task — but little far transfer to general thinking. A six-week study of 11,430 people found gains on every trained task and no carry-over to untrained ones.1
- A 2016 review of the 132 studies the brain-training industry put forward as its evidence concluded there is strong evidence brain-training improves the trained skill, but little evidence it improves everyday cognitive performance.2
- The brain exercise with the strongest real-world evidence isn't a puzzle or an app — it's physical exercise, which improves attention, executive function, and even hippocampal volume.5,6,7
- Learning a genuinely new and demanding skill — not repeating a familiar game — measurably improved memory in older adults.8
- The active ingredient across everything that works is the same: novelty, challenge, and sustained engagement — not the brand of app you use.
Do brain exercises actually work?
Brain exercises reliably make you better at the specific thing you practise, but the evidence that they broadly sharpen your general cognition is weak. That gap — between getting better at the task and getting better at life — is the single most important and most overlooked fact in the field.
When researchers ran a six-week online study in which 11,430 people trained on tasks targeting reasoning, memory, planning, and attention, participants improved on every task they practised. Yet there was no measurable transfer of those gains to other tasks, even closely related ones.1
Here's the thing — that doesn't make brain exercises useless. It means you have to be precise about what they actually do. A 2016 review in Psychological Science in the Public Interest scrutinised the 132 studies the brain-training industry itself put forward as evidence and reached a careful verdict: there's extensive evidence that brain-training improves performance on the trained tasks, less evidence it helps closely related tasks, and little evidence it improves distantly related tasks or everyday cognitive performance.2
So the honest answer to "do brain exercises work?" is: yes, for getting better at that exercise — and only sometimes for anything beyond it. The rest of this guide shows you which ones clear the higher bar.
What does "transfer" mean, and why does it matter?
Transfer is whether practising one mental task improves your performance on different tasks — and it's the difference between a party trick and a genuinely better brain. Scientists split it into near transfer (improvement on similar tasks) and far transfer (improvement on unrelated, real-world abilities). Near transfer is common; far transfer is rare and hard to prove.
This distinction is what most "brain exercise" articles quietly skip. Getting faster at a number-matching game is near transfer — impressive on screen, but it doesn't mean you'll remember names better or think more clearly in a meeting. A meta-analysis of working-memory training captured this neatly: training produced reliable short-term gains on working-memory measures, but no convincing evidence of far transfer to reasoning, verbal ability, reading, or arithmetic when compared against an active control group.3
What surprised me most when the research first landed is how consistent it is. Once you know to ask "near or far?", the marketing claims for most brain-training products fall apart — they're selling near transfer dressed up as far transfer. Keep that question in mind for everything below.
Do brain-training games and apps improve cognitive function?
For most people, commercial brain-training games and apps improve the games far more than they improve your daily life. The large-scale evidence is sobering: in the 11,430-person study, no amount of practice on the training games produced transfer to untrained abilities.1
The 132-study review reached the same conclusion about everyday performance.2 In 2016, the maker of one widely advertised brain-training app settled a US regulatory case over marketing claims it couldn't support — a sign of how far the promises had outrun the evidence.
That said, the picture isn't entirely negative — and this is where nuance matters. A meta-analysis of computerised cognitive training in healthy older adults found a small but measurable overall benefit, with one important catch: how the training was delivered changed everything. Group-based, supervised training produced gains, while unsupervised training done at home showed no significant effect.4 In other words, the structure and accountability may matter as much as the software you choose.
What this means for you is simple. If you enjoy brain-training apps, keep playing them — they're harmless and engaging. Just don't expect a daily ten-minute game to transform your memory or focus. The interventions with better real-world evidence are the ones that follow, and our guide to cognitive performance puts them in context.
Which brain exercises have the strongest evidence?
The brain exercises with the strongest real-world evidence share a feature that puzzles and apps often lack: they place broad, novel demands on the brain rather than drilling one narrow skill. The table below ranks the main categories by how strong the evidence is for far transfer — genuine improvement in your everyday cognition, not just the task you trained.
| Brain exercise | Evidence for real-world transfer | What it reliably improves |
|---|---|---|
| Aerobic / physical exercise | Strong | Attention, executive function, memory; hippocampal volume in older adults5,6,7 |
| Learning a new, demanding skill | Moderate–strong | Episodic memory (when novel and effortful)8 |
| Mentally + socially engaged lifestyle | Moderate (observational) | Lower long-term dementia risk; cognitive reserve9 |
| Supervised, structured cognitive training | Modest | The specific trained ability; durable for years4,10 |
| Working-memory drills (e.g. n-back) | Weak for far transfer | Working-memory test scores only3 |
| Commercial brain-training games / apps | Weak | The games themselves1,2 |
| Crosswords, Sudoku, puzzles | Limited / indirect | The puzzle skill; mild engagement benefit |
The pattern is hard to miss: the activities at the top aren't sold as "brain training" at all — yet they outperform the ones that are. Here's why, and what it means for where you put your effort.
Why is physical exercise the most reliable "brain exercise"?
The single best-evidenced way to improve your cognition isn't mental at all — it's physical movement, and the data is remarkably consistent. A meta-analysis of exercise interventions in adults over 50 found that physical exercise produced a modest but reliable improvement in overall cognitive function, with benefits from both aerobic and resistance training (a standardised effect of about 0.29).7
Even a single session helps, if modestly: a meta-analysis of 79 studies found that acute exercise produces a small improvement in cognition — most consistently in attention and executive function — both while you're moving and shortly afterwards.6
The mechanism is what makes it compelling. Aerobic activity raises levels of brain-derived neurotrophic factor (BDNF), a protein that supports the growth and survival of your neurons and underpins neuroplasticity. In a landmark trial, twelve months of moderate walking three times a week increased the volume of the anterior hippocampus — a key memory region — by around 2% in older adults, effectively reversing one to two years of age-related shrinkage; larger hippocampal volumes were, in turn, linked to better spatial memory.5 No puzzle has been shown to regrow brain tissue.
What this means for you is that a brisk walk, a swim, or a cycle is doing more for your thinking than almost any app on your phone. If you only adopt one "brain exercise" from this article, make it movement — the UK's NHS recommends at least 150 minutes of moderate activity a week, and your brain is one of the organs that benefits most. For the nutritional side of supporting an active brain, our review of supplements for focus and mental clarity covers what the evidence does and doesn't support.
Can learning a new skill improve cognition?
Learning a genuinely new and demanding skill is one of the few "mental" brain exercises with real transfer evidence. But the active ingredients are the novelty and the difficulty — the strain of doing something your brain hasn't yet automated — not the specific activity itself.
In the Synapse Project, researchers had older adults spend an average of around 16 hours a week for three months either learning something cognitively demanding and unfamiliar — digital photography or quilting — or doing more passive, familiar activities such as socialising or low-effort puzzles. Only the demanding, novel groups showed improved episodic memory afterwards.8
This is the finding I keep coming back to, because it reframes what a brain exercise is. The benefit didn't come from a clever training programme; it came from sustained struggle with something the brain hadn't automated yet. A crossword you've done a thousand times asks little of you. Learning to read music, speak Spanish, or code asks a great deal — and that effort is the point.
So the practical rule is to chase difficulty and novelty. Once a skill becomes comfortable for you, its training value drops — that's your cue to level up or learn something else. This is also how attention and memory improve together, a relationship explored in our guide to memory and learning.
Does staying mentally and socially active protect the brain long term?
A mentally and socially engaged life is associated with meaningfully lower long-term dementia risk, though this evidence is observational rather than proof of cause. A systematic review of "brain reserve" found that people with high levels of sustained, complex mental activity across their lives had roughly half the risk of developing dementia compared with those with low mental activity.9 The idea is cognitive reserve: a richer, more connected brain can tolerate more age-related change before problems show up.
This is also where structured cognitive training earns its place — narrowly. In the ACTIVE trial, older adults trained in reasoning or speed-of-processing retained measurable benefits on those specific abilities up to ten years later, far longer than most interventions manage.10 One later analysis even linked the speed-of-processing training to a lower risk of dementia,11 though that was a secondary finding rather than the trial's main aim and remains debated, so it's best treated as promising rather than settled. And combining approaches may matter most: the FINGER trial showed that a two-year programme pairing exercise, diet, cognitive training, and vascular monitoring improved cognition more than advice alone.12
What this means for you is that "use it or lose it" holds up better as a lifestyle than as a single daily drill. Staying curious, socially connected, and willing to learn is a long game with real stakes — and it's a theme we develop in our guide to brain health after 50.
So how do you actually train your brain?
The brain training that actually works isn't a product — it's a set of principles you can apply to almost any activity: choose things that are novel, genuinely challenging, and sustained over time. Repeating a task your brain has already mastered builds little; staying at the edge of your ability builds a lot. That's why a new language beats a familiar puzzle, and why physical exercise — which constantly challenges coordination, pacing, and effort — punches above its weight.
A few evidence-based moves stack the odds in your favour. Move your body most days, since exercise has more supporting evidence than any other cognitive intervention.5,7 Pick one demanding new skill and stick with it past the awkward early stage.8 If you study or learn for work, use active recall — testing yourself rather than re-reading, which produces stronger, longer-lasting retention than passive review.13 And protect the foundations that all of this depends on: sleep, stress management, and nutrition, which our explainer on nootropics and the wider Knowledge Centre cover in depth.
The reassuring part is that none of this requires a subscription. Your brain responds to how you live far more than to any single exercise — and that's something you have real control over.
Frequently Asked Questions
Do brain-training apps like Lumosity really work?
Brain-training apps reliably make you better at their own games, but the evidence that they improve everyday thinking is weak. Large studies have found gains on trained tasks with little or no transfer to untrained abilities.1,2 They're enjoyable and harmless, but a daily app session is not a substitute for exercise, learning, and good sleep.
What is the single best brain exercise?
If one activity has to win, it's physical exercise. It has the strongest real-world evidence of any "brain exercise," improving attention, executive function, and memory, and even increasing hippocampal volume in older adults.5,7 A brisk daily walk does more measurable good for your brain than most mental games.
Do crosswords and Sudoku improve cognitive function?
They mainly make you better at crosswords and Sudoku. Puzzles offer mild mental engagement and are a pleasant habit, but there's limited evidence they produce broad cognitive improvement — especially once the puzzle type becomes familiar and automatic. Novelty and difficulty are what drive benefit, so varying and increasing the challenge matters more than the puzzle itself.
How long does it take for brain exercises to work?
It depends on what you mean by "work." You'll improve at a trained task within days to weeks. Real-world benefits from the better-evidenced approaches take longer — exercise studies typically run weeks to months, and the skill-learning research used around three months of sustained practice.5,8 Consistency over months matters far more than intensity in any single session.
Can brain exercises prevent dementia?
No single brain exercise has been shown to prevent dementia. However, a lifelong pattern of mental and social engagement is associated with substantially lower dementia risk, and multidomain programmes combining exercise, diet, and cognitive activity show promise.9,12 Think of it as reducing your risk across a lifetime, not a guarantee from any one activity.
Are brain exercises better than supplements for cognition?
They address different things and aren't really competitors. Physical exercise and skill-learning have strong evidence for supporting your cognition, while supplements may help fill specific nutritional gaps that brain function depends on. The strongest approach for you combines healthy habits with adequate nutrition rather than relying on either alone.
Why don't brain-training gains transfer to real life?
Because most training drills one narrow skill, and your brain tends to get efficient at that exact task without rewiring the broader networks behind general cognition. This is the difference between near transfer (the trained task) and far transfer (everyday thinking), and far transfer is genuinely hard to produce — which is why broad, novel, effortful activities tend to beat repetitive drills.2,3
Supporting Your Brain Health with BrainSmart
Brain exercises work best on a well-supported brain, and nutrition is one input among several — alongside movement, learning, sleep, and stress management — that helps cognitive function. No supplement replaces the habits in this article, but targeted nutritional support can complement them.
Explore our range:
- BrainSmart Ultra — Comprehensive brain support
- BrainSmart Focus — Concentration and mental clarity
- BrainSmart Memory — Memory and recall
- BrainSmart Mood — Emotional wellbeing and stress
Related Reading
These guides go deeper on the topics raised above.
- The Complete Guide to Cognitive Performance
The pillar guide this article belongs to, covering mental sharpness end to end.
- How to Improve Focus and Concentration Naturally
The practical habits that support the brain you're trying to train.
- The Science of Attention: Why Your Brain Loses Focus
How attention actually works, and why focus slips.
- Best Supplements for Focus and Mental Clarity
What the evidence supports on the nutritional side.
- Nootropics Explained: What They Are and How They Work
The wider category of cognitive-support compounds.
- Memory and Learning: How Your Brain Stores and Strengthens Information
How memory and learning depend on the systems brain exercises engage.
- Brain Health After 50: Evidence-Based Strategies for Cognitive Longevity
Protecting cognition as you age, including cognitive training.
- Magnesium and the Brain
A nutrient with roles in sleep, mood, and cognition.
- Mood, Stress, and Your Brain
How stress affects the brain systems that learning depends on.
Important: This article is for general information and isn't medical advice. The research here is about habits and activities, not treatments. If you have a health condition, take medication, or are considering supplements, check with your GP or a qualified healthcare professional first.
References
- Owen AM, Hampshire A, Grahn JA, et al. Putting brain training to the test. Nature. 2010;465(7299):775-778. doi:10.1038/nature09042
- Simons DJ, Boot WR, Charness N, et al. Do "brain-training" programs work? Psychological Science in the Public Interest. 2016;17(3):103-186. doi:10.1177/1529100616661983
- Melby-Lervåg M, Redick TS, Hulme C. Working memory training does not improve performance on measures of intelligence or other measures of "far transfer": evidence from a meta-analytic review. Perspectives on Psychological Science. 2016;11(4):512-534. doi:10.1177/1745691616635612
- Lampit A, Hallock H, Valenzuela M. Computerized cognitive training in cognitively healthy older adults: a systematic review and meta-analysis of effect modifiers. PLoS Medicine. 2014;11(11):e1001756. doi:10.1371/journal.pmed.1001756
- Erickson KI, Voss MW, Prakash RS, et al. Exercise training increases size of hippocampus and improves memory. Proceedings of the National Academy of Sciences. 2011;108(7):3017-3022. doi:10.1073/pnas.1015950108
- Chang YK, Labban JD, Gapin JI, Etnier JL. The effects of acute exercise on cognitive performance: a meta-analysis. Brain Research. 2012;1453:87-101. doi:10.1016/j.brainres.2012.02.068
- Northey JM, Cherbuin N, Pumpa KL, Smee DJ, Rattray B. Exercise interventions for cognitive function in adults older than 50: a systematic review with meta-analysis. British Journal of Sports Medicine. 2018;52(3):154-160. doi:10.1136/bjsports-2016-096587
- Park DC, Lodi-Smith J, Drew L, et al. The impact of sustained engagement on cognitive function in older adults: the Synapse Project. Psychological Science. 2014;25(1):103-112. doi:10.1177/0956797613499592
- Valenzuela MJ, Sachdev P. Brain reserve and dementia: a systematic review. Psychological Medicine. 2006;36(4):441-454. doi:10.1017/S0033291705006264
- Rebok GW, Ball K, Guey LT, et al. Ten-year effects of the advanced cognitive training for independent and vital elderly cognitive training trial on cognition and everyday functioning in older adults. Journal of the American Geriatrics Society. 2014;62(1):16-24. doi:10.1111/jgs.12607
- Edwards JD, Xu H, Clark DO, Guey LT, Ross LA, Unverzagt FW. Speed of processing training results in lower risk of dementia. Alzheimer's & Dementia: Translational Research & Clinical Interventions. 2017;3(4):603-611. doi:10.1016/j.trci.2017.09.002
- Ngandu T, Lehtisalo J, Solomon A, et al. A 2 year multidomain intervention of diet, exercise, cognitive training, and vascular risk monitoring versus control to prevent cognitive decline in at-risk elderly people (FINGER): a randomised controlled trial. The Lancet. 2015;385(9984):2255-2263. doi:10.1016/S0140-6736(15)60461-5
- Roediger HL, Karpicke JD. Test-enhanced learning: taking memory tests improves long-term retention. Psychological Science. 2006;17(3):249-255. doi:10.1111/j.1467-9280.2006.01693.x
Tom Kaplan
Brain Health Writer at BrainSmart
Tom Kaplan is a specialist health writer focused on cognitive health, brain nutrition, and evidence-based approaches to supporting mental performance across the lifespan. His work draws on peer-reviewed research across neuroscience, nutritional psychiatry, and cognitive psychology — translating complex clinical findings into clear, practical guidance that helps readers make informed decisions about their brain health. Read Full Bio →