Performance and Physiologic Responses to Repeated 3-Minute All-Out Shuttle Tests.

Abstract: Mendelson, BJ, Ebersole, KT, Brau, SD, and Ebersole, NT. Performance and physiologic responses to repeated 3-minute all-out shuttle tests. J Strength Cond Res XX(X): 000-000, 2025-The purpose of this investigation was to examine changes in performance capacity in repeated all-out efforts. Ten participants (24.00 ± 4.32 years, 79.71 ± 46.05 kg, 1.79 ± 0.102 m) completed a maximal treadmill test with direct breath-by-breath and heart rate (HR) analysis to capture maximal aerobic capacity (V̇o2peak, mL·kg-1·minute-1) and HR (HRPEAK-TM, bpm). Participants also completed three 30-meter shuttle sprint 3-minutes all-out test (3 MT) bouts, from which critical velocity (CV, m·second-1), anaerobic work capacity (D', m), maximal sprint speed (SMAX, m·second-1), and the difference between SMAX and CV (SMAX-CV, m·second-1) were calculated. The 30-second end-3MT average HR (HREND-3MT, bpm), pretest blood lactate (LA-PRE, mmol·L-1), and post-test blood lactate (LA-POST, mmol·L-1) captured physiologic responses to the 3 MT session. Repeated measures ANOVAs (⍺ = 0.05) indicated that CV (F = 1.401, p = 0.270) did not significantly change across bouts, but D' (F = 7.271, p = 0.005) and SMAX (F = 7.474, p = 0.004) significantly decreased across bouts. HREND-3MT was significantly lower than HRPEAK-TM (F = 11.961, p < 0.001), and the LA-POST did not significantly change across bouts (p > 0.05). Correlation analysis indicated that V̇o2peak was significantly related to CV in bout 1 (r = 0.745, p = 0.013) and bout 3 (r = 0.746, p = 0.013). CV may be a repeatable level of performance but the ability to work more than the CV is significantly diminished in repeated all-out efforts. Further research is needed to examine methods to improve repeatability of D'.