ODRO
The first time I tried orienteering, back in 2011, my two teammates and I found ourselves locked in a back-and-forth battle with another team. We were grown men, veterans of the national running team; they were 13-year-old girls.
It was a race called Raid the Hammer, featuring 37 checkpoints scattered throughout a conservation area near Hamilton. The organizers figured the best route would be about 25 kilometres long, but the actual distance you covered would depend on how well you navigated.
At each checkpoint, we would encounter the team of 13 year olds. Then we would plunge back into the forest, confident that our superior running speed would leave them in the dust – only to meet them again at the next checkpoint. We were fast, but they were crushing us on the navigation.
That memory bubbled to the surface when I read a recent study from researchers at McMaster University. They tested the effects of orienteering on brain function and memory, comparing it to plain old exercise at a similar intensity. The results, which were published in the journal PLoS One, add to a growing pile of evidence that engaging your brain while you work out can supercharge the cognitive benefits of exercise.
Exercise seems to boost brain health in different ways, both immediately and over the long term. For example, it triggers the production of brain-derived neurotrophic factor, or BDNF, which spurs the growth of new neurons in the hippocampus, a region of the brain associated with learning and memory.
That’s important because the hippocampus is shrinking by about half a per cent per year by the age of 55, and that shrinkage is associated with declines in learning, memory, and spatial thinking.
The McMaster researchers were looking for more immediate effects based on emerging ideas about the role of lactate. Traditionally, lactate – or, as it used to be referred to, lactic acid – was thought to be a “poison” that made your muscles burn during exercise. But scientists now believe that it functions as both a chemical signal and as a fuel for cells throughout the body, including brain cells.
“We think that this is where lactate has its shining moment,” says Emma Waddington, the McMaster graduate student who led the new study along with Jennifer Heisz, who directs the university’s NeuroFit Lab.
The lactate you produce during hard exercise fuels your brain cells and also sends a signal to activate BDNF. The BDNF, in turn, facilitates “long-term potentiation,” which essentially means that the connections between any nerves that happen to be firing will be strengthened. That implies that what you do with your brain during exercise matters because those are the neural pathways that will be reinforced.
To test this idea, Waddington had 63 volunteers complete a 1.3-kilometre route in one of three conditions: walking, running, or running while navigating, i.e. orienteering. Before and after, they took blood tests to measure lactate and BDNF and administered a series of cognitive tests.
Sure enough, with or without navigation, running produced higher levels of lactate and BDNF than walking, and the volunteers with the highest lactate levels also had the highest BDNF levels. Running also produced better scores on one of the memory tests than walking. But only running with navigation produced better scores on a test of spatial memory. In other words, it was the specific brain circuits they’d used during the orienteering workout that got the biggest boost.
Waddington’s results fit with an emerging consensus that engaging your brain, rather than simply settling into autopilot, can offer some unique benefits. Last year, for example, a multicentre trial led by researchers at Western University found that a mix of aerobic exercise and cognitive training warded off cognitive decline more effectively than exercise alone.
As for that team of 13 year olds who put my orienteering skills to shame back in 2011, it turns out that one of them was Emma Waddington, who, in addition to being a brain science researcher, is now a regular on Canada’s national orienteering team. I don’t feel so bad any more.
Alex Hutchinson is the author of Endure: Mind, Body, and the Curiously Elastic Limits of Human Performance. Follow him on Threads @sweat_science.
