How physical exercise makes your brain work better

Research shows different activities have quite specific mental effects – here’s how moving your body could sharpen your ideas

The brain is often described as being “like a muscle”. It’s a comparison that props up the brain training industry and keeps school children hunched over desks. We judge literacy and numeracy exercises as more beneficial for your brain than running, playing and learning on the move.

But the brain-as-muscle analogy doesn’t quite work. To build up your biceps you can’t avoid flexing them. When it comes to your brain, an oblique approach can be surprisingly effective. In particular, working your body’s muscles can actually benefit your grey matter.

Scientists are showing that the runner’s high and the yogi’s tranquility have profound effects on your brain. Moreover, specific physical activities can markedly alter its structure in precise ways.

A wave of studies exploring the unexpected links between mental and bodily fitness is emerging from labs. This research might give you the impetus to get more active. It can also help you choose the best ways to prepare physically for mental challenges such as exams, interviews and creative projects.

Boost your memory

The part of the brain that responds strongly to aerobic exercise is the hippocampus. Well-controlled experiments in children, adults and the elderlyshow that this brain structure grows as people get fitter. Since the hippocampus is at the core of the brain’s learning and memory systems, this finding partly explains the memory-boosting effects of improved cardiovascular fitness.

As well as slowly improving your memory hardware, exercise can have a more immediate impact on memory formation. German researchers showed that walking or cycling during, but not before, learning helped new foreign language vocabulary to stick. So exercise while you revise. Don’t push it too hard, though: vigorous workouts can raise your stress levels, which can scupper your memory circuits.

Slowing cognitive decline

The evidence that staying physically fit keeps your brain healthy into old age is especially compelling. Most concrete is the link between aerobic fitness and cognitive preservation. Workouts needn’t be extreme either: 30-45 minutes of brisk walking, three times a week, can help fend off the mental wear and tear and delay the onset of dementia. It pays to get used to regular exercise early, though. The protective effects are clearest before the cognitive signs of old age kick in.

Nor is it all about your heart and lungs. Exercises to improve balance, coordination and agility made a clear impact on the brain structure and cognitive function of a large group of German elderly people. Twice weekly sessions of weightlifting can have a visible neurological impact. Dancing may also be restorative for ageing brains. Just an hour of dance a week, for six months, did little for elderly participants’ aerobic capacity, but the physical and social stimulation bolstered their cognitive wellbeing.

Researchers are still teasing out the critical factors that make exercise such a potent brain tonic. Prime suspects include increased blood flow to the brain, surges of growth hormones and expansion of the brain’s network of blood vessels. It’s also possible that exercise stimulates the birth of new neurons. Until recently, few believed this could happen in adult human brains.

Don’t sit still

The cognitive spillover from exercise reminds us that our brains don’t operate in isolation. What you do with your body impinges on your mental faculties. Sitting still all day, every day, is dangerous. So don’t dither about what form of exercise you do. Find something you enjoy, then get up and do it. Right, I’m off for a jog.