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08:27
A Real-World High-Intensity Interval Training Protocol for Cardiorespiratory Fitness Improvement
Published on: February 22, 2022
Five Weeks of Sprint Interval Training Increase Absolute Power Output Within Severe-Intensity Domain Without Altering
Rodrigo Araujo Bonetti de Poli1,2, Juan Manuel Murias2, Yago Medeiros Dutra1
1Laboratory of Physiology and Sport Performance (LAFIDE), São Paulo State University - UNESP, School of Sciences, Bauru, Brazil.
European Journal of Sport Science
|June 19, 2026
Summary
Five weeks of sprint interval training (SIT) improved cycling power output but did not significantly change neuromuscular function (NMF) or fatigability in active males. However, SIT may enhance electromyographic (EMG) activity efficiency during severe-intensity exercise.
Area of Science:
- Exercise Physiology
- Sports Science
- Human Performance
Background:
- Sprint interval training (SIT) is a time-efficient exercise strategy.
- Its effects on neuromuscular function (NMF), electromyographic (EMG) activity, and fatigability during severe-intensity cycling remain incompletely understood.
- Understanding these adaptations is crucial for optimizing training protocols.
Purpose of the Study:
- To investigate the impact of a 5-week SIT program on NMF, EMG activity, and fatigability during constant work rate (CWR) exercise in the severe-intensity domain.
- To determine if SIT improves cycling performance at a constant workload.
- To assess changes in neuromuscular responses and exercise tolerance post-training.
Main Methods:
- Twenty-one recreationally active males were randomized into a SIT group (n=11) or a control group (CON, n=10).
- The SIT group completed 5 weeks of SIT (4-6 bouts of 30-second Wingate tests).
- Participants underwent pre- and post-training assessments including ramp incremental tests, CWR exercise at 150% of respiratory compensation point power output (RCP-PO) to task failure, and NMF/EMG measurements.
Main Results:
- The SIT group demonstrated a significant increase in absolute RCP-PO compared to the CON group (+11.0% vs. -0.7%, p < 0.01).
- Post-training CWR exercise was performed at a greater power output in the SIT group.
- No significant differences were observed in baseline NMF, fatigability, or EMG activity during CWR exercise between groups, suggesting improved EMG efficiency.
Conclusions:
- SIT can enhance cycling performance, indicated by increased power output at the respiratory compensation point.
- Despite performance improvements, SIT did not significantly alter baseline neuromuscular function or reduce exercise-induced fatigability.
- Findings suggest SIT may improve EMG efficiency, enabling higher power output with similar neural activation during severe-intensity exercise.
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