When I first tried orienteering in 2011, two teammates and I were in a fierce battle with the other teams. We were adult men, veterans of national running teams, whereas they were 13-year-old girls.
It was a race called “Raid the Hammer,” with 37 checkpoints scattered throughout a nature reserve near Hamilton. Organizers estimated the optimal route would be about 25 kilometres, but the actual distance would depend on how well you navigated the route.
At each checkpoint we met a team of 13 year olds and charged off into the woods, confident that our superior running speed would allow us to beat them. Only to run into them again at the next checkpoint. We were faster, but they outshone us in navigation.
That memory came back to me when I read about a recent study by researchers at McMaster University. They compared the effects of orienteering on brain function and memory with regular exercise of a similar intensity. The results: Published in PLoS OneThere’s growing evidence that engaging your brain while exercising can further enhance the cognitive benefits of exercise.
Exercise appears to boost brain health in a variety of ways, both in the short and long term. For example, exercise stimulates the production of brain-derived neurotrophic factor (BDNF), which promotes the growth of new neurons in the hippocampus, an area of the brain associated with learning and memory.
This is important because the hippocampus shrinks by about 0.5% per year by age 55, and this shrinkage is associated with declines in learning, memory, and spatial thinking.
McMaster University researchers were looking for a more immediate effect based on new ideas about the role of lactic acid. Traditionally, lactic acid (previously called lactate) was thought to be a “poison” that burns muscle during exercise. But scientists now think that lactic acid functions as a chemical signal and as fuel for cells throughout the body, including brain cells.
“We think this is where lactate shines,” says Emma Waddington, a graduate student at McMaster University who led the new study with Jennifer Heise, director of the university’s NeuroFit Lab.
The lactic acid produced during intense exercise feeds brain cells and also signals them to activate BDNF, which promotes “long-term potentiation” – strengthening the connections between firing neurons. So what you do with your brain during exercise matters, because it’s the neural pathways that get strengthened.
To test this idea, Waddington had 63 volunteers complete a 1.3-kilometer route in one of three conditions: walking, running, or running while navigating (orienteering). Before and after, they took blood tests to measure lactate and BDNF, and completed a battery of cognitive tests.
Sure enough, running, with or without navigation, produced higher lactate and BDNF levels than walking, and volunteers with the highest lactate levels also had the highest BDNF levels. Running also produced better scores than walking on one of the memory tests. But only running with navigation produced better scores on the spatial memory test. In other words, it was the specific brain circuits used during orienteering training that got the biggest improvements.
Waddington’s findings fit into an emerging consensus that activating the brain, rather than simply settling on autopilot, offers some unique benefits. For example, last year Multicenter study A study led by researchers at Western University found that combining aerobic exercise with cognitive training was more effective at preventing cognitive decline than exercise alone.
As for the team of 13-year-olds that surpassed my orienteering prowess in 2011, it turns out one of them was Emma Waddington, a neuroscience researcher and now a regular on Canada’s national orienteering team. I don’t feel so bad anymore.
Alex Hutchinson is the author of Endure: Mind, Body, and the Curiously Elastic Limits of Human Performance. Follow him on Threads. Follow.
