Neurology · Medical Literature
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.
Abstract
Football coaches commonly provide verbal encouragement and exercise end-point feedback to sustain players' effort by enhancing motivation during fitness training such as high-intensity interval training (HIIT). However, the influence of such cues on the prefrontal cortex (PFC), a region involved in exercise cessation decisions, remains unclear. Therefore, this study aimed to compare the effect of motivational cues on PFC activation during HIIT using functional near-infrared spectroscopy, alongside physiological and perceptual responses. Twenty-two male elite footballers completed two randomised crossover HIIT sessions on a cycle ergometer, with and without motivational cues. Each session consisted of 12 repetitions of 30-s high-intensity bouts, each interspersed with a 30-s active recovery bout. Heart rate, lactate concentration, rating of perceived exertion (RPE), motivation-related questionnaires and oxygenated haemoglobin (HbO2) concentration in the PFC were measured throughout HIIT. Although physiological responses were similar between conditions, perceived difficulty, assessed every three HIIT bouts, was significantly lower under the motivational condition, with lower RPE (p = 0.038) and higher motivation (p = 0.049), engagement (p = 0.038) and mood (p = 0.009) scores, particularly after the 9th repetition. From the 10th to 12th repetition of HIIT, the HbO2 concentrations of the orbitofrontal cortex and frontopolar PFC were significantly lower under the motivational condition (p = 0.040 and p = 0.036, respectively), whereas the dorsolateral and ventrolateral PFC showed no significant difference between conditions. In conclusion, motivational cues reduce central PFC activity during the most fatiguing phases of HIIT, reflecting enhanced neural efficiency under motivation despite equivalent physical workloads.
Clinical relevance
This study addresses the underexplored neurophysiological mechanisms by which verbal motivational coaching cues modulate prefrontal cortex (PFC) activity during high-intensity exercise in elite athletes, a population at risk for central fatigue-driven performance decrements. Using functional near-infrared spectroscopy (fNIRS), it provides objective neural correlates—specifically oxygenated haemoglobin (HbO2) dynamics—to explain perceptual changes previously attributed solely to psychological factors. Clinicians in sports neurology and rehabilitation medicine should attend to these findings as they inform evidence-based protocols for exercise prescription, fatigue management, and neuromodulatory coaching strategies in high-performance and clinical exercise settings.
Key findings
1. Perceived difficulty was significantly lower under the motivational cue condition, with reduced RPE (p = 0.038), particularly pronounced after the 9th of 12 HIIT repetitions, without any corresponding differences in physiological load. 2. Motivation scores were significantly higher in the motivational cue condition (p = 0.049), accompanied by significantly higher engagement (p = 0.038) and mood scores (p = 0.009), indicating a robust perceptual and affective benefit of verbal coaching. 3. HbO2 concentration in the orbitofrontal cortex (OFC) was significantly lower under the motivational condition during repetitions 10–12 (p = 0.040), suggesting reduced neural recruitment in a region implicated in effort-cost appraisal and exercise cessation. 4. HbO2 concentration in the frontopolar PFC was also significantly lower under the motivational condition during the most fatiguing phase, repetitions 10–12 (p = 0.036), consistent with enhanced neural efficiency rather than greater cortical engagement. 5. The dorsolateral PFC (dlPFC) and ventrolateral PFC (vlPFC) showed no significant between-condition differences in HbO2 concentration, suggesting that motivational cues exert region-specific, not global, modulation of prefrontal activation. 6. Physiological responses—including heart rate and blood lactate concentration—were equivalent between the motivational and control conditions across all 12 HIIT repetitions, confirming that perceptual and neural differences were not confounded by differential physical workload (specific p-values not reported in the abstract).
Practice implications
Sports neurologists and exercise medicine specialists should incorporate structured motivational verbal cues as an evidence-based, zero-risk adjunct to HIIT protocols in elite athletes, particularly timed to the final third of training sessions (e.g., after the 9th repetition in a 12-bout protocol), where OFC and frontopolar PFC fatigue-mediated exercise cessation signals are most active. The demonstration of reduced PFC HbO2 without physiological change supports a neural efficiency framework, suggesting that motivational cueing may extend tolerance to high-intensity effort by attenuating perceived difficulty at the central—rather than peripheral—level, which is clinically relevant for designing rehabilitation exercise protocols in neurologically impaired or post-concussion populations. fNIRS monitoring of OFC and frontopolar PFC HbO2 dynamics warrants consideration as a practical, wearable biomarker for real-time assessment of central fatigue and motivational state during exercise stress testing in athletic and clinical neurology settings.