The effects of cadence changes at gas exchange threshold on metabolic, neuromuscular, and gait kinematic characteristics

Introduction This study investigated metabolic, neuromuscular, and gait responses to cadence manipulation at gas exchange threshold (GET) speed in 15 male Tier 2 middle- and long-distance runners. Methods Participants completed five 5-min treadmill bouts at 90%, 95%, 100%, 105%, and 110% of baseline cadence (BC); BC was tested first and the other conditions were randomized. Analyses used corrected repeated-measures ANOVAs, family-adjusted paired contrasts, and repeated-measures correlations. Results Relative to BC, oxygen uptake (VO 2 ) increased at 90% BC by 4.51 mL·kg –1 ·min –1 (simultaneous 95% CI 1.82–7.19; adjusted p < 0.001) and at 95% BC by 2.58 mL·kg –1 ·min –1 (0.47–4.69; adjusted p = 0.010); oxygen and energy costs were also significantly higher at both cadences. Heart rate, respiratory exchange ratio, and estimated carbohydrate contribution increased at 90%, 95%, and 110% BC (all adjusted p ≤ 0.029). At 90% BC, ground contact time increased by 31.33 ms and hip and knee range of motion increased by 2.94° and 3.60°, respectively (all adjusted p < 0.001). At 110% BC, contact time decreased by 24.67 ms (adjusted p = 0.019) and knee range of motion decreased by 6.23° (adjusted p = 0.008), without a significant reduction in oxygen or energy cost. No surface electromyography outcome passed the primary corrected omnibus test, but gluteus maximus root-mean-square amplitude correlated positively with VO 2 within participants (r_rm = 0.454, 95% CI 0.242–0.618, q = 0.006). The exploratory cadence–VO 2 curve was convex, with a fitted minimum near 101.35% BC. Discussion These findings identify higher metabolic costs below preferred cadence and distinct physiological and kinematic responses at higher cadence. They support evaluating cadence through both metabolic and biomechanical outcomes; the fixed-first BC design limits causal identification of an optimum.