We go to the gym, lift weights, get our protein in and train our muscles — and the body, quite reliably, responds. We get stronger, stamina improves, muscles grow.

But can the same logic apply to the brain?

We have spent years calling it a muscle, and there is some truth behind the comparison: learning, education and experience can physically change the brain. But somewhere after school and university, many of us seem to stop thinking about it as something we can actively train. You might keep learning, of course, but where is the equivalent of adding another five kilos to the bar?

So today, we are diving into the world of “brain training” to answer one question: can we train the brain with the same intention that we train the body? And if so, what actually counts as a brain workout? A serious cognitive training programme? 15 minutes a day on one of the dozens of apps promising a sharper mind?

Time to find out.

It can feel as though anything that makes our brain work particularly hard should count as brain training. But does the crossword you do over breakfast qualify? What about a game of chess with a friend? Reading a detective novel? Or the forensic psychological analysis of a conversation screenshot your friend has just sent you?

Well, this is where terminology matters.

First, there isn't really one single thing called “brain training”. What we are usually talking about is training particular cognitive functions: memory, attention, processing speed, reasoning and the like. And these abilities are not interchangeable. Improving your memory doesn't automatically make you faster at processing information; training your attention doesn't necessarily make you better at reasoning. You have to ask a much more specific question: what exactly are you trying to train?

Take two people:

Person A does a difficult crossword every morning because they enjoy it. They retrieve words, search their memory, make associations and solve clues. Their brain is absolutely being challenged. This is cognitive stimulation.

Person B wants specifically to improve working memory. They follow a programme where they have to remember sequences of information, the difficulty adapts to their performance, and they practise repeatedly over several weeks. This is cognitive training.

The first activity isn't worse or less useful. It simply isn't designed around systematically improving a predefined cognitive function. And importantly, the same activity can potentially move between the categories depending on how you use it. If you casually play a memory game because it is fun, that is cognitive stimulation. If you use progressively harder memory tasks according to a structured programme specifically to improve working memory, that's cognitive training.

Still sounds slightly intimidating? Here is a simpler example.

Say you want to build muscle. Walking to the supermarket gets your body moving. Lugging the shopping home might even challenge it. But you probably wouldn't call either of those strength training. For that, you go to the gym with a particular goal, repeat certain exercises and gradually make them harder as you get stronger. Brain training follows much the same logic.

We now know that brain training isn't about somehow upgrading the brain as a whole. It is much more specific: working memory, processing speed, attention and other cognitive functions can each be trained through exercises designed to target them. And if you want to give it a try, what could be more accessible than an app on your phone?

The App Store and Google Play are certainly not short of options. Cogmed, Lumosity and NeuroNation offer exercises targeting working memory. BrainHQ has tasks built around processing speed. CogniFit all venture into attention, while Elevate focuses more heavily on verbal skills, from vocabulary and reading comprehension to verbal processing. On paper, it sounds almost too convenient: decide what you want to improve, download the corresponding app and start training.

Except there is one rather important question left: does any of it actually work?

Well, that depends on what we mean by work.

Imagine you spend a month using an app to train your working memory. At the end of it, you are better at remembering sequences and perform better on another, similar working-memory task. Great. But what you probably really want to know is whether anything changes outside the app. Are you now better at concentrating during a long meeting? Do you remember names more easily? Can you solve unfamiliar problems faster?

Brain-training research has names for these two very different kinds of improvement: near transfer and far transfer.

Near transfer means that training one task makes you better at that task or something closely related to it. And here, brain-training apps have some decent evidence behind them. A meta-analysis of 43 studies involving 2,636 people looked at seven commercial programmes, including Lumosity, BrainHQ, CogniFit and Cogmed, and found small but significant improvements on tasks closely related to those being trained.

So if an app repeatedly asks you to identify information quickly, remember sequences or manipulate things in your working memory, you can indeed get better at those kinds of tasks.

Far transfer is the bigger promise. This is when an improvement travels beyond what you have actually been practising and makes a difference to other cognitive abilities — or, ultimately, to how your brain performs in everyday life.

And this is where the evidence becomes much less convincing. A 2025 study of computerised brain training in healthy older adults found that participants improved on the tasks they practised, but researchers found no evidence that those gains transferred to other trained or untrained cognitive tasks.

So, do brain-training apps work? Yes — but the important question is how far. Getting better at the cognitive skill an app trains is one thing. Expecting those gains to spill over into a generally sharper, faster, better-performing brain is quite another.

The answer depends on what exactly you want from your brain. There are three slightly different questions you might actually be asking.

1. Do you want to improve a specific cognitive skill?

Let's say you are a public speaker and remembering long stretches of text is practically as essential to your job as food and water. Then yes, targeted cognitive training may be worth exploring. There are exercises designed to train specific abilities, from working memory to processing speed, and, as we have already seen, people can get better at the functions they practise.

The important word here is specific. If you know what you want to improve, you can choose a form of training built around it.

2. Do you simply want your brain to work better day to day?

Perhaps you feel perfectly healthy and your brain is doing its job just fine — you would simply like to concentrate more easily, think a little faster and stay focused for longer.

Here, cognitive exercises are only one small part of the picture. How well your brain performs on any given day is also heavily influenced by everything happening outside the training itself: how well you slept, how physically active you are, what you eat, your stress levels and your overall physical and mental health.

Take sleep. A 2024 meta-analysis of 44 studies in which participants were restricted to just 2 - 6 hours of sleep found that even one night of sleep restriction impaired sustained attention: people reacted more slowly and had more lapses in attention.

In other words, you can spend 15 minutes training your attention on an app, but if you slept for four hours, don't expect it to magically produce a razor-sharp brain the next morning.

3. Do you want to keep your brain active as you age and reduce the risk of cognitive decline?

Then the conversation changes again. Rather than thinking about “brain training” in the narrow sense, it may be more useful to think about keeping the brain cognitively engaged throughout life.

This is where another important concept comes in: cognitive reserve. One more technical term, I know, but I promise this is the last piece of the puzzle. Put very simply, people differ in how well their brains can cope with age-related changes or disease before those changes begin to noticeably affect everyday life. Cognitive reserve is one way researchers try to explain that difference. And importantly, the factors associated with cognitive reserve don't seem to matter only when we are young. A 2024 meta-analysis found that higher cognitive reserve was associated with a lower risk of dementia across the lifespan: 18% lower for early-life factors, 9% lower for midlife factors and 19% lower for later-life factors.

Remember where we started? The crossword over breakfast, a game of chess, a detective novel, even that forensic analysis of your friend's latest messages? This is where those things come back into the picture. They may not count as targeted cognitive training, but they are all ways of keeping the brain engaged — and when we are talking about cognitive reserve, that broader engagement matters.

Building it doesn't appear to mean doing the same memory exercise every morning. Education, intellectually demanding work, learning new skills and staying mentally and socially active have all been associated with greater cognitive reserve. Even something as ordinary as staying socially connected matters: in the same meta-analysis, stronger social connections later in life were associated with around a 30% lower risk of dementia.

So perhaps the better question isn't simply “Should I train my brain?”, but “What do I actually want from it?”

Improving your memory, feeling mentally sharper tomorrow and supporting your cognitive health over the next 40 years are three very different goals — and they don't necessarily require the same kind of training.