(45) Determining the Validity of Conducting an Incremental Cycling Test and the Three-Minute All-Out Test in the Same Testing Session

Introduction: Critical power (CP) represents the maximal work rate in which a metabolic state steady state can be achieved. The three-minute all-out test (3MT) has been shown to be a valid and reliable single visit assessment of CP. Currently, it is recommended that the 3MT be completed on a separate day from other assessments such as incremental cycling test (ICT). However, previous investigations have reported 30 minutes of recovery between time-to-exhaustion trials is sufficient to obtain a valid assessment of CP.

Purpose: The purpose of this investigation was to determine if completing an ICT and 3MT on the same day separated by 30 minutes of rest would provide a valid assessment of CP.

Methods: Participants completed two testing sessions separated by at least 48 hours but no more than 10 days. Visit 1, participants completed an individualized increment cycling test (ICT) to exhaustion. The ICT was immediately followed by 3 minutes of active recovery at 50W followed by a square-wave bout verification protocol at 105% of peak power output (PPO) to exhaustion. Maximal oxygen consumption (VO₂max) was recorded as the highest VO₂ achieved during either the ICT or verification protocol along with the corresponding power (pVO₂max). Data collected from ICT was used to set alpha linear factor for 3MT. After completion of verification protocol, participants rested for 30 minutes before beginning the 3MT. Participants began with three-minutes of unloaded cycling, followed by three-minutes of all out cycling. Participants were instructed to pedal all-out with no pacing, and were provided strong verbal encouragement throughout. CP was calculated as the average power over the final 30 seconds of the test, and W prime (W’) was calculated as the work performed above CP during the first 150 seconds of the test. Participants completed the same procedures for the 3MT on Visit 2. Statistical differences in CP and W’ between Visit 1 (same) and Visit 2 (separate) were determined with paired-samples t tests. The agreement between CP and W’ values were assessed using mean difference, 95% confidence intervals (95%CI) of mean difference, and limits of agreement (LOA). Pearson’s correlation was used to assess the strength of the relationship between CP and W’ values assessed on Visit 1 and Visit 2. If significant correlations were present, linear regression was used to calculate values for the standard error of the estimate (SEE). Data are reported as mean ± standard deviation.

Results: No statistical differences were detected in CP (CP_same vs. CP_separate, 276.7 ± 22.0 Watts (W) vs. 278.9 ± 39.0 W, p=.882, d=0.06) and W’ (W’_same vs. W’_separate, 13.5 ± 6.0 kilojoules (kJ) vs. 14.5 ± 5.5 kJ, p=.691, d=0.17). A mean difference of 2.23 ± 40.9 W (95%CI: -31.9 to 36.4) and 1.0 ± 6.7 kJ (95%CI: -4.6 to 6.5) were observed for CP and W’, respectively. No statistical significant associations was detected between CP_same and CP_seperate (r=.198, p=.638) or W’_same and W’_separate (r=.325, p=.432). LOA for CP and W’ were -77.8 to 82.3 W and -12.1 ± 14.1 kJ, respectively.

Conclusion: Though no significant differences were detected between measuring CP and W’ on the same day as an ICT and measuring on a separate day, the lack of significant correlation and large LOA prevent recommending conducting an ICT and 3MT on the same day, Practical applications: The current recommendations of separate days for conducting an ICT and the 3MT should be followed by coaches and athletes.


Acknowledgements: None