Predicting intermittent running performance: critical velocity versus endurance index

Area of Science:

• Exercise Physiology
• Sports Science
• Human Performance

Background:

• Assessing endurance performance during intermittent exercise is complex.
• Critical Velocity (CV) and Endurance Index (EI) are potential metrics.
• Previous research has not definitively established their efficacy in intermittent protocols.

Purpose of the Study:

• To evaluate the effectiveness of CV and EI in assessing endurance performance during intermittent running.
• To compare the predictive capabilities of CV and EI across different intermittent exercise durations.
• To investigate the relationship between these indices and maximal anaerobic running capacity.

Main Methods:

• Thirteen subjects completed two intermittent running protocols (15s work/15s rest and 30s work/30s rest) until exhaustion.
• Exercise intensities were set at 100%, 95%, and 90% of the speed at the end of the 30-15 Intermittent Fitness Test (V(IFT)).
• Calculated intermittent Critical Velocity (iCV), intermittent Anaerobic Distance Capacity (iADC), and intermittent Endurance Index (iEI). Maximal Anaerobic Running Test (VMART) assessed anaerobic capacity.

Main Results:

• Exhaustion time (ET) was longer in the 15/15 protocol compared to the 30/30 protocol at similar intensities.
• iCV and iADC did not correlate with VMART or show significant relationships with ET.
• iEI was higher in the 15/15 protocol and demonstrated a strong correspondence with longer ET, indicating better endurance estimation.

Conclusions:

• The intermittent Endurance Index (iEI) is a valid and reliable measure for estimating endurance capacity during repeated intermittent running exercise.
• Intermittent Critical Velocity (iCV) and intermittent Anaerobic Distance Capacity (iADC) are less effective for assessing endurance in these protocols.
• The findings highlight the superiority of iEI for evaluating performance in intermittent exercise scenarios.