The 9/3 Min Running Test: A Simple and Practical Approach to Estimate the Critical and Maximal Aerobic Power

Abstract

This study aims to determine the validity of the linear critical power (CP) and Peronnet models to estimate the power output associated with the second ventilatory threshold (VT2) and the maximal aerobic power (MAP) using two-time trials. Nineteen recreational runners (10 males and 9 females and maximum oxygen uptake: 53.0 ± 4.7 mL/kg/min) performed a graded exercise test (GXT) to determine the VT2 and MAP. On a second test, athletes performed two-time trials of 9 and 3 min interspaced by 30 min. The CP was determined from the linear CP model and compared with the power output associated with the VT2. The MAP was determined from the linear Peronnet model, established at 7 min, and compared with the MAP determined in the GXT. The CP model was valid for determining the VT2, regardless of sex (p = 0.130; 9/3 vs. GXT: 3.5 [-1.1 to 8.2] W). The MAP was overestimated (p = 0.015) specifically in males (9/3 vs. GXT: 9.2 [3.3 to 15.1] W) rather than in females (p = 9/3 vs. GXT: 1.7 [-4.4 to 8.0] W). Therefore, MAP estimates were determined introducing the CP and W' parameters to a stepwise multiple linear regression analysis. For females, the CP was the unique significant predictor of MAP (p < 0.001) explaining 96.7% of the variance. In males, both CP and W' were significant predictors of MAP (p < 0.001) explaining 97.7% of the variance. Practitioners can validly estimate the VT2 and MAP through a practical testing protocol in both male and female recreational runners.

Keywords: modelling; running; severe intensity domain; training.

FIGURE 1

The illustration of the experimental design and modeling of the linear transformation of the Peronnet and critical power (CP) models to estimate the power output associated to the second ventilatory threshold (VT2) and the maximal aerobic power (MAP).

FIGURE 2

Power outputs associated with the second ventilatory threshold (VT2) and the maximal aerobic power (MAP) determined from the graded exercise test (GXT) and from the ones derived from the modeling of the 9 and 3 min time trial.

FIGURE 3

Comparison between the MAP (y‐axis) and its time limit (x‐axis) between the Peronnet model (black dot) and the ones obtained in the graded exercise test (grey dot). The 9 and 3 min power outputs are also illustrated (white dots).

FIGURE 4

The level of agreement between the observed maximal aerobic power (MAP) values at the graded exercise test (GXT) and the ones obtained from the specific equations proposed for females and males using the critical power (CP) and the work over CP (W') as predictors.