Brain health, memory and focus

Does exercise improve memory and learning?

Probably a little. Exercise tends to give a small to moderate boost to thinking overall, and a similar-sized boost to memory¹. In adults over 50, exercise improved thinking whatever their starting point³. The size of the benefit is uncertain, and no clear minimum amount has been shown. If you're starting from little activity, light activity is a reasonable place to begin¹. Programmes of three months or less did better than those running beyond six months, so a long programme isn't essential¹.

What is neuroplasticity, and how does exercise help it?

Neuroplasticity is the brain's ability to change its structure, cells and chemistry. Exercise may support this and so help learning and memory⁴. The clearest support comes from animals, where exercise increased growth factors linked to neuroplasticity⁵. In people the picture is much less settled. Suggested routes, such as more blood vessels in the brain and less inflammation, are things exercise may do, not measured results¹.

Can exercise improve executive function?

Probably, but modestly. Executive function covers skills such as planning and switching between tasks. In healthy older adults, moderate-intensity aerobic and strength training done at least 3 times a week, in sessions of 60 minutes or less, over 26 weeks or less improved it⁶. Across all ages the effect was small¹. The benefit isn't seen in every group, so treat it as a possible bonus of staying active.

What is BDNF, and why does exercise raise it?

BDNF (brain-derived neurotrophic factor) is a growth-related factor involved in how brain cells work and in brain health. In older adults, some training programmes raised resting levels in the blood, while others changed them little^7,8. Why exercise might raise BDNF is a suggestion rather than established fact⁶. Don't read a higher level as meaning better memory or focus; that link isn't established.

How does activity improve blood flow to the brain?

Exercise training changes blood flow in some parts of the brain. Scans showed consistent increases in the hippocampus and one other area, but not across the whole brain⁹. A single session of mild-to-moderate aerobic exercise could raise brain blood flow, while very hard exercise led to a decline⁴. You don't need to push very hard. Whether a lasting rise in blood flow leads to better thinking isn't yet established⁴.

Can activity improve focus and concentration?

The picture is mixed. A single bout of exercise has been followed by faster information processing⁴. Short, regular breaks from sitting, such as a brisk walk every 30 minutes, are tentatively suggested to help short-term attention¹⁰. In adults over 50, the benefit of regular exercise was consistent across the thinking skills tested³. How big any effect on focus is remains unclear.

What simple activities boost everyday brain function?

Any movement counts. The WHO says health benefits occur below the recommended amounts, and that replacing sitting with activity of any intensity, including light, has benefits². Even light exercise may give a worthwhile thinking benefit¹. Walking, gardening, housework and carrying shopping all count, and there are chair-based options if mobility is limited¹¹. Several short bouts of 10 or 15 minutes can be easier than one long session¹². Aim for moderate effort: breathing a little harder, but still able to talk, not sing.

Does strength training help your brain?

Probably, for some aspects of thinking. Resistance training improved overall thinking scores and executive function, but not working memory, and results varied widely¹³. In adults over 50, aerobic exercise, resistance training, multicomponent training and tai chi all showed benefits for thinking³. For general health, the WHO recommends muscle-strengthening on 2 or more days a week². Build up gradually.

How does aerobic exercise change brain structure?

The best-supported change is protection rather than growth: aerobic exercise appeared to prevent the loss of hippocampus volume that happens over time¹⁴. Scans of overall brain structure in people are mixed. Some showed more grey and white matter, while one found no difference in brain volume after a year of exercise⁵. Nothing shows that these changes explain better thinking.

How does physical health affect brain health?

Heart and blood-vessel health is linked with brain health, but the link is an association, not proof of cause. Even light physical activity has been linked with better brain health, and more sitting with poorer thinking performance¹⁵. Staying active and sitting less are sensible steps, but they aren't a guarantee.

Can exercise help with brain fog?

Exercise can't be promised to clear brain fog. Talk to a doctor if brain fog is frequent, gets in the way of work or daily activities, or is getting worse¹⁶. Memory problems don't necessarily mean dementia; they can have other causes, such as depression, anxiety or side effects of some medicines¹⁷. Don't try to work out the cause yourself, and don't treat exercise as a substitute for getting persistent memory problems checked.

Does exercise change the brain (for example, hippocampus growth)?

Mostly in animals. Growth of the hippocampus after aerobic exercise has been consistently seen in animals, but the human findings are equivocal¹⁴. The clearest human signal is protective: exercise appeared to slow the usual loss of volume rather than make the hippocampus bigger¹⁴. Some people's scans show other changes in grey and white matter, but not consistently⁵.

How is cardiovascular fitness linked to thinking skills?

The link is not straightforward. In older people without known memory problems, aerobic exercise improved fitness, but the fitness gain did not coincide with better thinking¹⁸. So don't use your fitness level as a measure of your brain, and keep activity for the many other benefits it brings.

Do diet and exercise affect inflammation in the brain?

Exercise may reduce inflammation in the body, which is one possible explanation for its thinking benefits, not a proven one¹. In people with mild cognitive impairment, exercise had a certain effect on lowering inflammation markers in the blood¹⁹. These are blood markers, not measures of inflammation in the brain. Whether diet changes brain inflammation isn't clear yet.

When to check with a health professional

If you're starting exercise after a long break, it's always a good idea to see your doctor first. For an injury or a health condition, see a health professional, such as your doctor or a physio.

Don't exercise when you're unwell. If you feel breathless, dizzy, light-headed or have palpitations while exercising, stop, sit down and rest, and see a doctor if it persists¹¹. Muscle soreness a day or two later is normal; for a sore muscle or joint, ease off and see a doctor if it lasts.

Call your local emergency number for chest pain or pressure (or pain spreading to the arm, neck, jaw or back, especially with sweating or feeling sick), severe breathlessness, fainting or collapse, signs of a stroke, a serious injury, or someone who isn't safe.