The Self-Paced Submaximal Run Test: Associations With the Graded Exercise Test and Reliability.

Purpose: To assess the reliability and construct validity of a self-paced, submaximal run test (SRT\(_{RPE}\)) for monitoring aerobic fitness. The SRT\(_{RPE}\) monitors running velocity (v), heart rate (HR\(_{ex}\)), and blood lactate concentration (B[La]), during three 3-minute stages prescribed by ratings of perceived exertion (RPEs) of 10, 13, and 17. Methods: Forty (14 female) trained endurance runners completed a treadmill graded exercise test for the determination of maximal oxygen consumption (VO\(_2\)max), v at VO\(_2\)max (vVO\(_2\)max), and v at 2 mmol·L\(^{−1}\) (vLT1) and 4 mmol·L\(^{−1}\) (vLT2) B[La]. Within 7 days, participants completed the SRT\(_{RPE}\). Convergent validity between the SRT\(_{RPE}\) and graded exercise test parameters was assessed through linear regression. Eleven participants completed a further 2 trials of the SRT\(_{RPE}\) within a 72-hour period to quantify test–retest reliability. Results: There were large correlations between v at all stages of the SRT\(_{RPE}\) and VO\(_2\)max (r range = .57–.63), vVO\(_2\)max (.50–.66), and vLT2 (.51–.62), with vRPE 17 displaying the strongest associations (r > .60). Intraclass correlation coefficients (ICC\(_{3,1}\)) were moderate to high for parameters v (range = .76–.84), HR\(_{ex}\) (.72–.92), and %HR\(_{max}\) (.64–.89) at all stages of the SRT\(_{RPE}\). The corresponding coefficients of variation were 2.5% to 5.6%. All parameters monitored at intensity RPE 17 displayed the greatest reliability. Conclusions: The SRT\(_{RPE}\) was shown to be a valid and reliable test for monitoring parameters associated with aerobic fitness, displaying the potential of this submaximal, time-efficient test to monitor responses to endurance training.