Moderate intensity exercise can benefit memory performance

Three experiments involving a total of 59 people provides more evidence that moderate intensity exercise (e.g., brisk walking, water aerobics, cycling) is enough for cognitive improvement. Indeed, moderate intensity exercise had the most beneficial effect on memory performance.

The experiments compared exercise at three levels of intensity (low, moderate, high), high-intensity interval training (HIIT), active rest (cognitive engagement), and passive rest (no cognitive activity). Memory was tested using a recognition test with an 80–90 minute retention interval (people were shown items, then 80-90 minutes later, had to say whether an item was the same as one seen before, or new).

High & low exercise intensity found to influence brain function differently

A study involving 25 male athletes has found that low-intensity exercise triggers brain networks involved in cognition control and attention processing, while high-intensity exercise primarily activates networks involved in affective/emotion processing.

The athletes exercised on a treadmill, performing low- and high-intensity exercise bouts for 30 minutes on separate days.

Exercising good for your gray matter

A German study involving 2,013 adults (aged 21-84) found that better cardiorespiratory fitness was strongly associated with increased gray matter volume and total brain volume. Particular brain regions affected were the left middle temporal gyrus, righ hippocampal gyrus, left orbitofrontal cortex, and bilateral cingulate cortex.

Cardiorespiratory fitness was measured using peak oxygen uptake and other standards while participants used an exercise bike.

Cardiorespiratory exercise includes walking briskly, running, biking and just about any other exercise that gets your heart pumping.

Exercise protects against brain shrinkage

A review of 14 clinical trials which examined brain scans from 737 people before and after aerobic exercise programs or in control conditions concluded that aerobic exercise significantly increased the size of the left region of the hippocampus, though it had no effect on total hippocampal volume (implying that the right side shrank).

Importantly, the effect on brain volume was not due to an increase in brain matter, but protection against the shrinkage that occurs over time. In other words, as one researcher noted, exercise can be seen as a maintenance program for the brain.

Participants included healthy adults, people with mild cognitive impairment such as Alzheimer’s and people with a clinical diagnosis of mental illness including depression and schizophrenia. Ages ranged from 24 to 76 years with an average age of 66.

The researchers examined effects of aerobic exercise, including stationary cycling, walking, and treadmill running. The length of the interventions ranged from three to 24 months with a range of 2-5 sessions per week.