Neuromuscular, cardiometabolic, and perceptual responses to a short sprint interval training session with different cycling torques.

Abstract

Purposes: Short sprint interval training (sSIT) can improve both aerobic and anaerobic indices through different protocol designs with sprinting bouts lasting ≤ 10 s. However, the limited available evidence does not allow the comprehensive understanding of the acute psycho-physiological effects of applying different torques during cycling sSIT protocols with very short, "all out" sprints. This study aims to evaluate the impact of high (HT) versus low (LT) torques on neuromuscular performance, cardiometabolic, and perceptual responses during a sSIT session of 5-s sprints.

Methods: After familiarizations and determination of HT and LT with a graded sprinting test, 15 physically active individuals completed, in randomized order, 2 sSIT sessions (12, 5-s sprints on a cycle ergometer) with HT and LT. Mechanical (i.e., power, cadence, and rate of fatigue), physiological [i.e., surface electromyography (sEMG), oxygen consumption (VO₂), heart rate (HR), blood pressure (BP) and muscle oxygenation (SmO₂)], and perceptual parameters [i.e., rating of perceived exertion (RPE) and affective valence] were assessed during sessions and acute recovery.

Results: Mean cadence and power, rate of fatigue, and RPE were higher in HT (p < 0.05), while time to peak power, sEMG amplitude, and affective valence were higher in LT (p < 0.05). Cardiometabolic parameters were similar during and after both protocols (p > 0.05).

Conclusions: The manipulation of torque in a sSIT protocol with 5-s sprints promotes different neuromuscular and perceptual responses, but with no differences between conditions for cardiometabolic responses. These findings are relevant for designing sSIT protocols to adapt neuromuscular and perceptual loading based on targeted outcomes for specific populations.