Author(s): AZZALI, G., AMATORI, S., DELL’ANNA, S., BERNARDES, A.G., LIBERALI, G., LUCCIONI, L., ALBINI, A., ZIGOLILLO, M., BALDARI, C., BOULLOSA, D.A., BUZZACHERA, C.F. , Institution: UNIVERSITY ECAMPUS, Country: ITALY, Abstract-ID: 2602

INTRODUCTION:
Short-term sprint interval training (sSIT), characterised by recurring sessions of brief (≤10 s), repeated bouts of intense exercise, is a potent stimulus for inducing physiological adaptations. Evidence suggests that certain adaptations are comparable to those induced by traditional Wingate-based SIT protocols. Most sSIT schemes, however, rely on repeated maximal efforts, which may not be appropriate for all populations. It remains unclear whether near-maximal efforts, achieved through reduced cycling torque or perceptual self-regulation, represent a safer and more practical alternative capable of inducing similar physiological adaptations while eliciting more favourable perceptual responses. Whether maximal and near-maximal sSIT schemes produce comparable acute psychophysiological responses also remains uncertain. Therefore, this study aimed to compare the acute physiological and perceptual responses to maximal versus near-maximal sSIT sessions, implemented through torque reduction or perceptual self-regulation.
METHODS:
Fourteen healthy young men (mean age: 24 ± 2 yr, V̇O2peak: 45.1 ± 4.4 mL∙kg⁻1∙min⁻1) completed a ramp incremental cycling test, followed by three single sSIT sessions. Each session comprised 8 × 5-s efforts interspersed with 45 s of active recovery and included one of the following conditions: (i) maximal efforts against a standard Wingate torque factor (TF = 0.7 Nm/kg); (ii) maximal efforts with a 10% reduced torque factor (TF = 0.63 Nm/kg); and (iii) perceptually self-regulated near maximal efforts targeting ~90% maximum intensity (TF = 0.7 Nm/kg). Power output, cadence, pulmonary gas exchange, and heart rate were recorded throughout the sessions. Blood lactate, ratings of perceived exertion (6-20), and affective valence (-5 to +5) were also assessed.
RESULTS:
Two-way RM-ANOVA with Bonferroni-adjusted post hoc tests revealed that both maximal-effort conditions, performed at different torque factors, elicited greater power output during sSIT sessions compared with the perceptually self-regulated near-maximal condition (P < 0.01). Similarly, pulmonary gas exchange and heart rate responses were significantly higher in both maximal-effort conditions (P < 0.01). These physiological differences were accompanied by greater perceived exertion and less pleasant affective valence the maximal-effort conditions compared the perceptually regulated condition (P < 0.05). Blood lactate concentrations were also higher in the maximal-effort conditions (P < 0.05).
CONCLUSION:
Our findings suggest that maximal and perceptually regulated near-maximal sSIT sessions elicit distinct acute psychophysiological responses. A modest reduction in torque factor did not attenuate physiological or perceptual responses when maximal effort was maintained. In contrast, perceptual self-regulation significantly altered both responses to sSIT. Further studies should determine whether these acute differences translate into divergent chronic adaptations.