A assesses the interoceptive powers of athletes. Interoception, the study explains, is 鈥渢he detection and perception of stimuli originating from within the body.鈥 I assumed this would be one of those feel-good studies鈥攖hat, in addition to being smarter and happier and living longer than average, trained runners would also turn out to be masters of tuning into their body鈥檚 signals. After all, pacing yourself in a prolonged effort is a fundamentally interoceptive challenge.
But the results turned out to be more complex than I expected. In fact, they raise some interesting鈥攁lbeit speculative!鈥攓uestions about whether listening to your body is as important as we think, and whether it might even be counterproductive in some circumstances.
The study was led by Hayley Young, a psychologist at Swansea University in Britain. She and her colleagues compared sprinters, distance runners, and non-athletes in two separate sub-studies. The athletes were further divided into two groups: elite (meaning they were ranked in the top 100 in Britain) and non-elite.
In the first study, 213 subjects filled out an online questionnaire assessing their self-reported interoceptive awareness. This involved various distinct elements like being aware of comfortable and uncomfortable bodily sensations, being able to direct your attention to bodily sensations, and being conscious of the links between bodily sensations and emotions.
The overall results showed that athletes scored more highly than non-athletes, which you鈥檇 expect, and sprinters scored more highly than distance runners, which is more surprising given the supposed link between interoception and pacing. When you look at the individual elements of interoception, the results are even more surprising: elite athletes, for example, report lower emotional awareness, self-regulation, and body listening.
Self-reporting has its limits, of course. Maybe the elite athletes are just more conscious of their own interoceptive shortcomings. So the second study tested interoception more directly in a smaller sample of 58 subjects. They completed two tasks. One involved sitting quietly and counting heartbeats during a prescribed period of time. This sounds really easy鈥攁fter all, I know how to take my pulse, and I鈥檓 very familiar with the pounding of my heart during or after exercise. But when I tried it at rest, it鈥檚 far more difficult than I expected. The problem is that it鈥檚 possible to fake a decent result without true interoception if鈥攍ike most athletes鈥攜ou know roughly what your resting heart rate is. The second test avoids that problem: while hooked up to an ECG, you watch a circle flashing on a screen and try to determine whether the circle is in sync or out of sync with your heartbeat.
The results, once again, were a mixed bag. Under normal conditions, the athletes and non-athletes produced similar scores on both tests鈥攁lthough the athletes tended to be more confident in their answers than the non-athletes. When they repeated the second test with simulated crowd noise as a distraction, the athletes did better than the non-athletes. But on the heartbeat counting test, elite athletes were once again significantly worse than non-elites.
How do we make sense of all these results? The safe conclusion is the one that Young and her colleagues go with: 鈥淎thletic populations have altered interoceptive abilities.鈥 Something is different with athletes, but we鈥檙e not sure what or why. Still, it鈥檚 interesting to consider some possible explanations.
One option is that being hypersensitive about what your body is feeling is actually a disadvantage in endurance sports, where most of what you鈥檙e feeling is bad news. That relates to a point I first heard from , a sports psychologist at Ulster University who studies the cognitive strategies used by endurance athletes. In the olden days, we used to divide those cognitive strategies into two bins: recreational runners tend to 鈥渄issociate鈥 (i.e. distract themselves) while elite runners tend to 鈥渁ssociate鈥 (i.e. focus intently on the task at hand and how they鈥檙e feeling). But Brick and others have found a more nuanced picture, in which runners shift between distraction and self-monitoring depending on the context鈥攁nd focusing too much on how you鈥檙e feeling during a challenging run might even make the task feel harder.
There鈥檚 also a body of research from the motor learning literature that says that familiar actions run more smoothly when you don鈥檛 focus internally on the component movements. Tying your shoes on autopilot is easier than remembering the bit about the bunny going around the tree. You鈥檒l hit more free throws by thinking about the ball going through the hoop than by thinking about keeping your elbow bent at the right angle. And you鈥檒l run more efficiently if you鈥檙e not hyperfocused on how your limbs are moving through space. This line of thinking applies to both sprinters and distance runners, offering an explanation for why both groups might be less tuned into their bodies.
Conversely, it could be that training and competing actually interfere with interoception. Perhaps repeatedly pushing your body beyond its comfortable limits forces you to ignore all the distress signals bombarding your brain. Over time, ignoring them becomes a habit, and you鈥檙e less able to judge how you鈥檙e feeling. Or perhaps it鈥檚 only modern runners whose interoception is impaired, thanks to their reliance on external sources of feedback like GPS watches and heart rate monitors.
Of course, it鈥檚 worth asking whether sitting in a chair counting heartbeats is a relevant test of an athlete鈥檚 interoceptive abilities. The signals that endurance athletes presumably tune into are those that affect performance and reveal whether a given effort level is sustainable, such as鈥 well鈥 what, exactly? When I鈥檓 in the middle of a race, I鈥檓 not counting heartbeats, or estimating lactate levels, or assessing core temperature. I鈥檓 tuned into a more general overall assessment of how hard I鈥檓 working relative to how hard I expect to be working at this point in the race鈥攚hat researchers call my perceived effort.
What is perceived effort? One view is that it鈥檚 the overall integration of all those other signals: heart rate, lactate levels, core temperature, and so on. This is the view that leads us to believe that elite endurance athletes should be better at interoception than sprinters and non-athletes.
But another view, laid out in , is that the sensation of effort doesn鈥檛 rely on feedback from the body at all. Instead, it鈥檚 generated entirely in the brain, and basically quantifies how 鈥渟trong鈥 a signal your motor cortex is sending out to the muscles. If your leg muscles are tiring, they won鈥檛 work as well, so the brain has to send a stronger signal in order to maintain your pace. Subjectively, you feel this as a higher level of effort.
I initially found this view鈥攖hat it鈥檚 the brain鈥檚 outgoing signals, not incoming signals, that generate the sensation of effort鈥攊mplausible. But the evidence is intriguing. The new review, led by Benjamin Pageau of the Universit茅 de Montr茅al, pools data from studies where incoming signals from muscle to brain are blocked with epidural drugs. Notably, perceived effort doesn鈥檛 decrease. So perhaps endurance athletes aren鈥檛 tuned into interoceptive signals because they don鈥檛 need to be: they鈥檙e getting all the information they need from within their brains.
For now, the only real conclusion we can draw is that the topic isn鈥檛 as obvious as we might have assumed. One of the key points Young makes is that interoception is too broad a concept. It鈥檚 highly unlikely that we鈥檒l ever end up concluding that listening to your body is 鈥渂ad鈥 overall. But we may find that some ways of listening, in some contexts, are more useful than others, and some might even be counterproductive for athletes. In the meantime, I鈥檒l be sitting here quietly trying to count my heartbeats.
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