Abstract
This study investigated the effects of three uphill gradients; shallow (SHG ~ 2.5%), intermediate (IHG ~ 5.1%), and steeper (STHG ~ 7.6%) on maximal velocity (Vmax), 800 m time trial (TT), and strength endurance (SE) performance in middle-distance runners. Forty moderately trained athletes (aged 16-20) were randomly assigned to SHG, IHG, STHG, or control (CG) groups (n = 10 each). Over 8 weeks, participants completed gradient-specific training. Vmax (30 m sprint), TT (800 m), and SE (1-min burpees) were assessed pre- and post-intervention. Two-way RM-ANOVA revealed significant main effects on Vmax (F(3,36) = 2.87, p = .049, [Formula: see text] = 0.20), TT (F(3,36) = 7.60, p < .001, [Formula: see text] = 0.39), and SE (F(3,36) = 5.19, p = .004, [Formula: see text] = 0.30). Post-hoc analysis showed STHG significantly outperformed CG in Vmax (mΔ = 0.93, p = .040), TT (mΔ = -0.29, p = .001), and SE (mΔ = 3.90, p = .007). IHG also improved TT vs. CG (mΔ = - 0.25, p = .007). The finding revealed that, uphill training, particularly steeper gradients, significantly enhances speed, endurance, and running performances. Therefore, coaches and athletes should customize training programs using uphill while carefully matching the strengths and weaknesses of the athlete and the demands of the event.