Coaches commonly use verbal encouragement and end‑point feedback to sustain effort during fitness sessions such as high‑intensity interval training (HIIT). The prefrontal cortex (PFC) is implicated in decisions to stop or continue exercise, but how motivational cues modulate PFC activity during demanding exercise remains unclear. This randomized crossover study used functional near‑infrared spectroscopy (fNIRS) to compare PFC activation, physiological responses and perceptual measures in elite football players performing HIIT with and without motivational coaching cues.
Twenty‑two male elite football players took part in a randomized crossover trial. Each participant completed two HIIT sessions on a cycle ergometer: one session with motivational coaching cues and one session without such cues. The exercise protocol comprised 12 repetitions of 30‑second high‑intensity bouts, each followed by a 30‑second active recovery period.
Throughout each session the investigators measured heart rate and blood lactate concentration. Perceptual and questionnaire measures included rating of perceived exertion (RPE), and motivation‑related questionnaires assessing motivation, engagement and mood. Cerebral oxygenation was assessed by fNIRS, recording oxygenated haemoglobin (HbO2) concentration across subregions of the PFC, including orbitofrontal, frontopolar, dorsolateral and ventrolateral areas.
Heart rate and blood lactate responses were reported as similar between the motivational and non‑motivational conditions. The source does not report additional physiological differences between conditions beyond these measures.
Perceptual measures diverged between conditions despite comparable physiological load. Ratings of perceived exertion (RPE), sampled every three HIIT bouts, were significantly lower in the motivational condition (p = 0.038). Motivation, engagement and mood questionnaire scores were significantly higher with motivational cues (p = 0.049, p = 0.038 and p = 0.009, respectively), with these differences particularly evident after the ninth repetition. The study therefore reports reduced perceived difficulty and enhanced self‑reported motivation and mood when coaching cues were supplied.
fNIRS recordings of oxygenated haemoglobin (HbO2) in the PFC showed region‑specific effects. From the 10th through the 12th HIIT repetition, HbO2 concentrations in the orbitofrontal cortex and the frontopolar PFC were significantly lower under the motivational condition (p = 0.040 and p = 0.036, respectively). By contrast, the dorsolateral and ventrolateral PFC subregions did not show significant differences between the motivational and control sessions.
These patterns indicate that motivational cues were associated with reduced activation—indexed by lower HbO2—in specific anterior PFC regions during the most fatiguing phase of the protocol.
The authors conclude that verbal motivational coaching reduces central activity in anterior PFC regions during late, fatiguing repetitions of HIIT, while physiological workload remains equivalent. They interpret the decreased HbO2 in orbitofrontal and frontopolar regions together with lower RPE and improved motivation/mood as evidence of enhanced neural efficiency under motivational states: athletes reported less perceived difficulty while performing the same physical work.
Keywords highlighted by the authors include fNIRS, high‑intensity interval training, motivation, neural efficiency and prefrontal cortex.
The abstract reports participant number, exercise protocol, the main outcome measures, regional HbO2 differences with p values, and changes in RPE and questionnaire scores. The source reports that physiological measures (heart rate and lactate) were similar between conditions. Details that are not provided in the abstract include the exact wording or timing of the motivational cues, the full questionnaire instruments, sample demographic details beyond sex and elite status, effect sizes and confidence intervals, and specifics on statistical models or correction for multiple comparisons. Those items are not reported in the PubMed abstract and would require consulting the full text for clarification.
For practitioners working with elite athletes, the findings suggest that targeted motivational coaching during HIIT can alter subjective experience and modulate activity in anterior PFC regions during the most demanding repetitions, without changing core physiological load. The data support a role for motivational strategies in modifying perceived exertion and PFC engagement—interpreted by the authors as improved neural efficiency—but further detail from the full article would be needed to inform precise coaching protocols and to assess generalizability.