Fryer, SM, Giles, D, Garrido Palomino, I, de la O Puerta, A, and España-Romero, V. Hemodynamic and cardiorespiratory predictors of sport rock climbing performance. J Strength Cond Res 32(12): 3543-3550, 2018-Rock climbing performance has been suggested to involve a notable contribution from aerobic metabolism. Previously, it has been shown that forearm oxygenation kinetics can be used to distinguish ability groups and predict red-point sport climbing performance. Currently, it is not known if forearm oxygenation kinetics or a sport-specific assessment of cardiorespiratory fitness best predicts sport rock climbing performance. The aim of the study was to determine whether forearm oxidative capacity index, maximal deoxygenation (Δ score) during a treadwall V[Combining Dot Above]O2peak test, treadwall V[Combining Dot Above]O2peak, or running V[Combining Dot Above]O2max best predicts self-reported sport climbing performance. Twenty-one male sport rock climbers completed a treadwall V[Combining Dot Above]O2peak, running V[Combining Dot Above]O2max, and an assessment of near-infrared spectroscopy-derived oxidative capacity index. Linear regression, adjusted for age and experience (years), revealed that forearm oxidative capacity index, treadwall maximal deoxygenation (Δ), and treadwall V[Combining Dot Above]O2peak all significantly predicted self-reported red-point sport climbing ability (Adj R = -0.398, -0.255, and 0.374, respectively), whereas treadmill running V[Combining Dot Above]O2max did not (Adj R = -0.052). Additionally, multiple regression suggested that the combined significant aerobic predictors accounted for 67% of the variance in red-point climbing ability. Findings suggest that training for sport rock climbing performance should look to incorporate modalities that focus on (a) improving local forearm aerobic capacity and (b) improving whole-body aerobic capacity using sport-specific apparatus, such as treadwalls.