This study examined the effect of ischemic preconditioning (IPC) on severe-intensity exercise performance, pulmonary V̇O2 kinetics, skeletal muscle oxygenation (TSI) and mitochondrial function. Eight males underwent contralateral IPC (4×5 min at 220 mmHg) or sham-control (SHAM; 20 mmHg) before performing a cycling time-to-exhaustion test (TTE; 92% maximum aerobic power). V̇O2 kinetics and vastus lateralis (VL) TSI were measured throughout trials. Muscle biopsies (VL) were obtained before IPC and SHAM and ~1.5 min post-exercise to determine mitochondrial respiration and citrate synthase activity (CS). TTE did not differ between SHAM and IPC (249 ± 37 vs 240 ± 32 s; P = 0.62). Pre- and post-exercise mitochondrial respiration through protein complexes (C) I-IV did not differ between trials (P > 0.05). Mass and CS corrected CI leak respiration (CIL) increased post-exercise compared with baseline in SHAM (1.9 ± 1.8 vs 4.5 ± 1.7 pmol.s-1.mg-1; P ≤ 0.05 and 0.10 ± 0.07 vs 0.29 ± 0.10 pmol.s-1.mg-1.CS-1; P = 0.003, respectively), but not IPC (3.2 ± 1.6 vs 3.9 ± 2.2 pmol.s-1.mg-1; P = 0.19 and 0.21 ± 0.10 vs 0.26 ± 0.15 pmol.s-1.mg-1.CS-1; P = 0.16, respectively). V̇O2 mean-response time was faster (51.3 ± 15.5 vs 63.7 ± 14.5 s; P = 0.003) with a smaller slow component (270 ± 10 vs 377 ± 188 ml·min-1; P = 0.03) in IPC compared with SHAM. TSI did not differ between trials (P > 0.05). IPC attenuated increased CIL, evoked by severe-intensity exercise, and expedited V̇O2 kinetics but did not improve exercise performance. All experimental procedures were approved by the Loughborough University Ethics Approvals Human Participants Sub-Committee (R19-P138),