Relationships Between Aerobic Capacity And Critical Velocity Measures In A Sprint-based 3-minute Test

Critical velocity (CV) has been linked to performance in sport and occupational settings. Additionally, the finite distance that can be achieved at speeds greater than CV (D’) is useful to understand exercise capacity above the CV. To date, relationships between CV, D’, and aerobic capacity (VO2PEAK) have been reported in a 3-minute all-out test (3MT) for continuous running (CR), but not in a repeated-sprint (RS) protocol. A RS test may be more feasible for measurement and application to sport or occupational settings that require agility-based components. PURPOSE: The purpose of this study was to identify relationships between CV, D’, and VO2PEAK in a sprint-based 3MT (3MT-RS). METHODS: Twelve participants (10 males, 2 females) completed a maximal ramp treadmill test where VO2PEAK was measured directly via breath-by-breath analysis (24.08 ± 3.92 yrs, 1.76 ± 0.13 m, 79.13 ± 16.12 kg). On another day, participants completed a 3MT consisting of repeated 30-meter (m) sprints and switchbacks. Sprint times were recorded and average velocity from 0-150 seconds was used to calculate D’. CV was calculated from the average velocity from 150-180 seconds. Difference between max sprint velocity (SMAX) and CV (SMAX-CV) was calculated to quantify change in sprint velocity across the test. Pearson-product correlations were run to identify relationships between VO2PEAK, CV, D’, SMAX, and SMAX-CV. An alpha of 0.05 determined statistical significance. RESULTS: Means ± SD were calculated for VO2PEAK (49.75 ± 4.29 mL/kg/min), CV (3.27 ± 0.45 m/s), D’ (117.31 ± 48.51 m), SMAX (5.55 ± 0.43 m/s), and SMAX-CV (2.28 ± 0.55 m/s). Correlation results indicated strong to very strong significant relationships between VO2PEAK and CV (r = 0.632, p = 0.027), CV and D’ (r = -0.863, p = 0.001), CV and SMAX-CV (r = -0.676, p = 0.016), and D’ and SMAX-CV (r = 0.832, p < 0.001). CONCLUSION: These results agree with relationships reported in CR protocols and suggest that higher aerobic capacity is related to a higher maximal sustainable work rate measured in the 3MT-RS. This higher sustainable work rate is related to a smaller decrease in sprint velocity, which may have implications for capacity to perform heavy or severe-intensity work. The 3MT-RS may be a meaningful assessment for athletes or occupations that require high sustainable work capacity.