Motivational coaching cues reduce prefrontal cortex activation during intense interval training
In a randomized crossover study of 22 elite male footballers, motivational cues delivered during high-intensity interval training (HIIT) lowered perceived exertion and altered brain activity in regions linked to fatigue decisions, despite identical physical workload.
Coaches often use verbal encouragement during fitness training, but the mechanism by which such cues affect the brain remains unclear. Researchers studied 22 male elite footballers performing two identical HIIT sessions on a cycle ergometer—one with motivational cues and one without—while measuring brain activity using functional near-infrared spectroscopy (fNIRS), alongside heart rate, lactate, and perceived exertion.
Each session consisted of 12 repetitions of 30-second high-intensity efforts separated by 30-second recovery periods. Although physiological responses (heart rate and lactate) were nearly identical between conditions, perceived difficulty dropped significantly under motivation: rating of perceived exertion (RPE) was lower (p = 0.038), while motivation, engagement, and mood scores were higher (p = 0.049, p = 0.038, and p = 0.009 respectively). Brain imaging revealed that during repetitions 10–12 (the most fatiguing phase), oxygenated haemoglobin concentrations in the orbitofrontal cortex and frontopolar prefrontal cortex were significantly lower under motivation (p = 0.040 and p = 0.036), suggesting reduced neural activation in regions involved in exercise-stopping decisions. Other prefrontal regions showed no change. The findings suggest that motivational cues enhance neural efficiency—the brain appears to work less hard to sustain effort when motivation is boosted, even though the body is working equally hard.
The study used fNIRS, a non-invasive brain-imaging technique that measures blood-oxygen changes in real time, allowing researchers to monitor prefrontal cortex activity during live exercise—a rare window into what happens in the brain during peak fatigue. The orbitofrontal cortex and frontopolar regions are involved in weighing effort costs and deciding when to stop; lower activation here under motivation suggests the brain is not re-evaluating the 'should I quit?' calculation as heavily. Notably, the effect emerged specifically in the final repetitions when fatigue accumulated, not uniformly across the workout. The effect size was modest but consistent: RPE dropped by roughly 0.5–1 point on the standard scale, and motivation scores rose. Prior work has shown that prefrontal activity correlates with perceived exertion and decision-making during exercise; this study adds the finding that external cues can modulate that activity independent of actual physical demand. A limitation is that the sample consisted only of elite male footballers, so results may not generalize to recreational athletes, women, or non-football populations.
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- Motivational Coaching Cues Can Modulate Prefrontal Cortex Activity and Perceptual Responses of Elite Football Players During High-Intensity Interval Training: A Randomised Crossover fNIRS Study. — European journal of sport science (Read the original)