The effect of IPC on central and peripheral fatiguing mechanisms in humans following sustained maximal isometric exercise

Ischemic preconditioning (IPC) is thought to inhibit neural feedback from metabolically sensitive muscle afferents during exercise. It was hypothesized that IPC could affect the mechanism of centrally mediated fatigue following a maximally fatiguing protocol. Eleven resistance trained males completed three 2 min maximal voluntary contractions (MVC's) via an isometric leg extension preceded by treatments of IPC (3 × 5 min bilateral leg occlusions at 220 mmHg), SHAM (3 × 5 min at 20 mmHg) or CON (30 min passive rest). Femoral nerve stimulation was utilised to explore central and peripheral fatigue pathways. This was profiled at baseline (BL), prior to the 2 min MVC (Pre), and then 10 s post (Post). Tissue oxygenation was measured throughout the 2 min MVC's via near‐infrared spectroscopy. Pre to Post MVC and twitch torque levels declined (‐71 ± 56; d = 1.33 ± 0.51, p < 0.007) (‐51 ± 20 Nm; d = 3.76 ± 0.84, p < 0.005) respectively without differences between conditions (MVC; p = 0.67, twitch torque, p = 0.39). Voluntary activation was also unaffected by condition (p = 0.8). Peak deoxyhaemoglobin concentrations were elevated (3.7 ± 3.0 μmol−L; d = 1.02 ± 0.46, p = 0.003) (3.0 ± 3.7 μmol−L; d = 0.82 ± 0.57, p = 0.03) in the IPC trials relative to CON and SHAM respectively. These findings demonstrate that IPC does not affect central or peripherally mediated mechanisms of fatigue during a sustained 2 min maximal effort isometric leg extension task.