Reliability analysis of the 3-min all-out exercise test for cycle ergometry

Area of Science:

• Exercise Physiology
• Sports Science
• Human Performance

Background:

• The 3-minute all-out exercise test (3 MT) is widely used to estimate critical power (CP) and anaerobic work capacity (W').
• It is also proposed as a method for measuring maximum oxygen uptake (VO(2max)).
• Previous reliability analyses of the 3 MT have primarily focused on CP, with limited investigation into W' and VO(2max) verification against established protocols like the graded exercise test (GXT).

Purpose of the Study:

• To conduct a reliability analysis of the 3-minute all-out exercise test (3 MT) for critical power (CP) and anaerobic work capacity (W').
• To compare maximum oxygen uptake (VO(2max)) measurements obtained from the 3 MT against a graded exercise test (GXT) and an exhaustive square-wave verification bout.

Main Methods:

• Eleven participants with varying aerobic capacities completed two separate 3 MT sessions.
• Critical power (CP), anaerobic work capacity (W'), and average power during the initial 150 seconds of the 3 MT were assessed.
• Measurements were analyzed for reliability using typical error (TE), coefficient of variation (CV), and intraclass correlation (α), alongside VO(2max) comparisons with GXT and square-wave protocols.

Main Results:

• The 3 MT demonstrated reliable estimation of CP (TE = 15 W, CV = 7%, α = 0.93) with no significant difference between trials.
• While W' showed lower reliability (TE = 2864 J, CV = 28%, α = 0.76), it did not significantly impact power-duration estimates.
• Variability in VO(2max) measurements was lower between the GXT and square-wave bout (TE = 1.16) compared to the 3 MT (TE = 2.03 and 2.69 for trials 1 and 2, respectively).

Conclusions:

• The 3 MT provides reliable estimates of critical power (CP) and consistent power-duration relationships.
• Average power output over 150 seconds is a more reliable measure of short-term power performance than W'.
• The square-wave protocol is recommended over the 3 MT for accurate verification of true maximum oxygen uptake (VO(2max)).