Swimming for a Real Brain Workout
Written by Daphne Crum
Edited by Samantha Strom
July 31st 2021
Edited by Samantha Strom
July 31st 2021
Could swimming laps sharpen the brain on a vascular and cognitive level? Dr. Leena Shoemaker and her research team from New Zealand’s Dunedin School of Medicine study the benefits of exercising to increase blood flow to the brain and improve cognitive functioning. Cycling and running have been found to increase Cerebral Blood Velocity (CBV), the rate at which blood flows from the body to the brain (Hellstrom et al., 1996; Jiang et al., 1995; Jorgensen et al., 1992; Ogoh and Ainslie, 2009; Shoemaker et al., 2019). Swimming laps can be just as intense a workout as cycling and running. The question is, can swimming boost cerebral blood flow and cognition as effectively?
To determine the true benefits of swimming on the body and mind, Shoemaker first isolated four factors that differentiate swimming from other sports: the extended time spent immersed in water, lying horizontally as opposed to standing vertically, the repetitive upper body motor involvement, and the varied breathing patterns that influence CO₂ retention and stamina. The goal was to figure out if any of these unique factors would independently alter CBV or cognitive retention; the test group included both water and land athletes to observe if the benefits of swimming would manifest differently between individuals of various swimming comfort levels (Shoemaker et al., 2019).
Strong, consistent blood flow to the brain allows the body to resupply the brain with oxygen and remove CO₂, so running cognitive and vascular tests after subjecting athletes to each of the four swimming factors was important for determining if reported cognitive abilities were directly correlated to changes in artery measurements (Shoemaker et al., 2019). Athletes in this study were asked to perform a series of land based-tasks, replicate them in a pool, and take breaks in between each task to run tests (Shoemaker et al., 2019). Tasks included holding upright and horizontal postures, holding both postures again with restrictions on how much CO₂ they could expel, and swimming breaststroke for 20 minutes. The cognitive tests that were run required the athletes to quickly identify colors of visual stimuli flashed in their peripheral vision, testing their inhibition, accuracy, and mental switching. Heart rates were also monitored and carotid ultrasounds were performed in the left middle cerebral artery, measuring the average diameter of the inner artery cavity and the velocity of blood flow for one minute.
What were the results? Swimming breaststroke for 20 minutes improved cognitive performance in land and water-based athletes by 4%, and independent tests for each swimming factor determined that posture and breathing restrictions contributed most significantly to this finding. Average CBV increased when athletes were upright or had breathing restrictions, and it decreased when athletes were oriented horizontally or free of breathing restrictions. Overall, the study suggests that swimming modifies cerebral blood flow and boosts cognitive functioning (Shoemaker et al., 2019). So forget crossword puzzles and memory games – if you need a mental boost, jump into the pool for a real brain workout!
References
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