Why swimming is great for brain health as well as the body, especially as we get older

This is the 65th instalment in a series on dementia, including the research into its causes and treatment, advice for carers, and stories of hope. My mother taught me to swim in a pool that was going green with algae. My memory of the day is much clearer than the water was. She urged me to leap from the side into her arms – and I did. She thought I ought to know how to swim, even though she herself hated it. I – like my maternal grandmother, who swam regularly into her eighties – grew to love it. Ever since I learned how, I have sought out places in which to swim, from pools to lakes and the sea. People often ask why I love swimming. “You just go up and down,” they say as I swim 50 lengths of a pool. Or, “Isn’t it cold?” It often is, but I keep swimming, and not just for the exhilaration that comes with exercise or just to keep physically fit. Swimming always seems to help me sort out my thoughts. My best ideas come while I swim. Like all physical activity, swimming is associated with better mental and physical health. It is also associated with better cognition and memory. Researchers are still learning about the benefits of swimming, says Dr Seena Mathew, assistant professor of biology at the University of Mary Hardin-Baylor in the US state of Texas, who is a recreational swimmer herself. “One benefit is that it is a whole-body exercise. When you look at factors involved in swimming [the resistance of water, the water pressure, the buoyancy, and simply being in water], it involves bilateral cross-pattern movements with the right and left sides of your body doing opposite movements,” she says. “The more you engage the halves of your brain and have them communicate with one another, the more efficient neurological patterns will be.” This leads to greater cognitive ability. Leena Shoemaker and Jim Cotter of the University of Otago in New Zealand are also studying the benefits of swimming. Cotter says that cognition improves during and after exercise, even in the absence of recent exercise, and even for those in their cognitive prime, such as young adults. Shoemaker says animal studies provide compelling evidence that neuronal growth factors – molecules involved in the development, survival, differentiation and maintenance of neurons – “play a very significant role in enhancing cognition with aerobic exercise training”. One study found that mice that swam for 10 minutes a day at least twice a day for 30 days had better memories than those who swam for only 15 days. This experiment did not just show the value of exercise for the brain, but the value of consistent, regular exercise. Maintaining a routine can be challenging as we get older and begin to feel the effects of wear and tear on our body. This is why Mathew considers swimming to be a “perfect exercise” – it is a low-impact, full-body exercise that has cardiovascular and muscular benefits without the toll on her joints that other exercises can take. Shoemaker and Cotter focused on swimming because it increases blood flow to the brain. There are key differences between swimming and land-based exercises. As well as taking place in a different environment and requiring a different posture and muscles, we also breathe much more rhythmically while swimming than during a gym workout or running. The different posture is significant. Shoemaker says posture “plays a key role in how our brain regulates blood flow. Because the brain depends on a steady supply of oxygen and nutrients, which are delivered through the blood, even brief interruptions can affect how well it works.” The older we are, the harder our bodies have to work to keep blood flowing upward. The reason we sometimes get dizzy after standing up quickly, Shoemaker says, is that “gravity suddenly pulls blood down toward your legs, temporarily reducing how much blood gets to your brain”. Our bodies automatically correct this, but sometimes not quickly enough, causing a person to faint – landing in a horizontal position. “In that position, gravity no longer pulls blood away from your brain, making it easier for blood flow to return to normal,” Shoemaker says. We also assume this horizontal position while swimming. In that position, blood flows more easily to our brains. Swimming at any age in life is good for us, but swimming as we get older appears to be especially beneficial. Judy Chan, 60, loves to swim. She trains three times a week, in the pool at the Kwun Tong Swimming Club, in Hong Kong, and in open water with endurance training company 26 Coaching. Chan says no one taught her and her six older siblings to swim. “We just went to the pool and the beach and learned by ourselves,” she says. Today she competes in open-water swimming events, as does her son, Robin Leung – who placed third in his age group at The 2025 World Masters Games in Taiwan. Chan believes swimming is good for the whole body, not just as a way to maintain your figure and strength, but also to build willpower and keep a clear mind. Mathew agrees. “I enjoy the ability to block out all of the sounds from the outside world when I get under the water and get lost in my own thoughts. I tend to work out details and thoughts while I am swimming, and it helps to clear my mind and lower stress.” Is swimming better for the brain than other kinds of exercise? No one knows for certain. For Chan, a swimming routine provides more than consistent exercise, better balance and improved strength. It makes her part of a community. Like what you read? 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Why swimming is great for brain health as well as the body, especially as we get older

Swimming is not just a great physical exercise but is also associated with better cognition and memory, and improved blood flow to the brain