by Danny Feldman of Lewis & Feldman
Several recent studies have shown that exercise, particularly moderate exercise, can decrease memory loss or even improve memory. The reasons for these findings vary. Research shows that exercise can enhance mood, improve sleep and reduce anxiety. Other studies have shown that regular exercise increases molecular targets, such as brain–derived neurotrophic factor (BDNF). The more BDNF the brain has, the more new synapses allow for easier absorption of information and long-term memories. Similarly, Irisin is a hormone that is typically never found in people with dementia or Alzheimer’s. The brain produces it as a result of exercise.

In addition, other studies have shown that different types of exercise benefit different kinds of memories. So, not only do people who exercise tend to have better memories than sedentary people, but people who engage in high-intensity exercise (think of a 55-minute Orangetheory workout) scored higher on spatial-learning tasks. While people who engaged in low to moderate exercise intensity, like walking or hiking, did better on naturalistic recall (remembering a narrative of events).

However, one study done in 2010 on marathon and ultra-distance runners showed that people who engaged in higher-intensity activities showed a decline in memory. Researchers are not sure why this is the case, but given that running a marathon exacts extreme stress on the body, it appears the brain is not immune. As one researcher observed, it’s as if the hippocampus is stressed and damaged in an ultra-distance event. So, the adage that if something is good for you, more of it is even better may not be accurate.

Finally, while studies have shown that while even one workout can help brain function, exercising consistently over six months showed noticeable improvements in memory. It also increased the size of the hippocampus, the area of the brain most associated with memory. In other words, even if you’ve been sedentary for many years, going for a daily walk should improve memory function, even if it’s only 20-30 minutes a day. The Department of Health and Human Services recommends 150 minutes of moderate activity (brisk walking) or 75 minutes a week of vigorous exercise (jogging) per week to keep your memory sharp.