PURPOSE: This study assessed the physiological durability of International and National, Junior and U23 triathletes following a simulated sprint-triathlon cycle. METHODS: Eight male International and National Junior and U23 triathletes (aged: 20.3 1.5 y, V˙O2peak: 66.0 3.9 mL·kg-1·min-1, 4.56 0.24 L·min-1) attended the laboratory on 3 occasions. Visit 1 comprised an incremental ramp test and time to task failure to establish running V˙O2peak, gas exchange threshold (GET), respiratory compensatory point (RCP), and associated velocities. Visit 2 determined cycling V˙O2peak, GET, RCP, and associated power during an incremental ramp protocol and a 10-second all-out sprint. Visit 3 consisted of a stochastic simulated sprint triathlon cycling protocol varying between power outputs associated with 50% Δ V˙O2peak and 10-second mean maximal power, 110% RCP, and 110% GET, prior to transitioning to the treadmill replicating visit 1 to determine "fatigued" running physiology and time to task failure (TTF). RESULTS: Significant changes in: V˙O2peak (mL·kg-1·min-1) (P = .006, d = -1.206 -0.254, -2.112), vV˙O2peak (km·h-1) (P = .008, d = -1.110 -0.190, -1.985), GET expressed as a percentage of V˙O2peak (P = .022, d = 0.866 0.021, 1.668), V˙O2 at RCP (mL·kg-1·min-1) (P = .020, d = -0.894 [-0.042, -1.704), vRCP (km·h-1) (P = .041, d = -0.717 -0.87-1.482), and TTF (in seconds) (P = .022, d = -0.866 -0.21, -1.668) were observed in a fatigued state. CONCLUSION: A simulated sprint-triathlon cycle elicits significant declines in Junior and U23 triathletes running physiology and performance indices. Substantial interindividual responses across physiological variables highlights the necessity for durability profiling within sprint-distance triathletes.
Langley et al. (Thu,) studied this question.