Validation of an 8-minute Self-Paced Graded Exercise Testing Protocol to Elicit Maximal Responses

Abstract

Recent examinations have turned to the development and validation of a 10-min self-paced graded exercise testing protocol. The 10-min duration was chosen because it represents the mean value of the recommended 8-12min ideal protocol duration; however, literature exists suggesting that an 8min duration may be more appropriate to elicit maximal exercise responses. Furthermore, a gender effect may exist to explain the finding. PURPOSE: We sought to examine maximal exercise responses during an 8-min self-paced (8SPV), 10-min self-paced (10SPV) and standardized graded exercise testing (GXT) treadmill protocols. METHODS: Sixteen recreationally active males (n=8) and females (n=8) completed three separate tests in a randomized order: a) 8SPV consisting of eight 1-min stages of increasing speed clamped by the Borg RPE6-20 scale, b) 10SPV consisting of five 2-min stages clamped of increasing speed clamped by the Borg RPE6-20 scale, c) traditional Bruce protocol as the GXT. 8SPV and 10SPV maintained a 3% grade. A two-way (gender x protocol) ANOVA with repeated measures was employed to examine differences in maximal responses between protocols. Paired samples t-tests were used to examine the difference in maximal velocity between 8SPV and 10SPV. RESULTS: No gender effects were revealed. Maximal values for 8SPV, 10SPV and GXT were similar (p > 0.05) for oxygen consumption (48.0±5.6; 51.8±10.5; 51.4±7.5 mL•kg-1•min-1), heart rate (193±11; 195±9; 194±13 beats•min-1), respiratory exchange ratio (1.11±0.07; 1.12±0.06; 1.13±0.05), ventilation (103.2±22.4; 113.0±30.3; 112.3±33.0 L•min-1), respectively. Maximal velocity for 8SPV and 10SPV were also similar (15.1±3.1 vs. 14.6±2.7 km•hr-1, p > 0.05). CONCLUSION: Given no differences between protocols, 8SPV may serve as a valid and time efficient option to elicit maximal responses during self-paced exercise in recreationally trained college-aged men and women.