The Effects Of Acute Resistance Exercise On Subsequent Cycling Performance And Skeletal Muscle Oxygenation

BACKGROUND: Post-activation performance enhancement (PAPE) occurs when a high-intensity conditioning contraction leads to improved muscle performance in a subsequent trial. While the effects of PAPE on muscle power and anaerobic performance are well-documented, its impact on cardiovascular outcomes and endurance performance is less understood. The influence of PAPE on skeletal muscle oxygenation during exercise, a key determinant of exercise tolerance, remains unclear. PURPOSE: This study aimed to assess the effects of acute hex bar deadlifts (HBD), used as a PAPE stimulus, on subsequent cycling exercise tolerance and skeletal muscle microvascular oxygen delivery-utilization matching in humans. METHODS: Fourteen healthy participants (23 ± 1 years, 10 M/4F) were involved in a randomized crossover trial, performing cycling exercise following either HBD or dynamic stretching (DYN) interventions. Participants completed moderate (MOD) and severe (SEV) intensity cycling tests with measurements of heart rate (HR), blood pressure (BP), pulmonary oxygen uptake, and vastus lateralis muscle oxygenation (SmO2; near-infrared spectroscopy). RESULTS: No significant difference was observed in the primary outcome of time-to-exhaustion during SEV intensity cycling between the HBD and DYN conditions (HBD: 452 ± 46 s, DYN: 397 ± 45 s; p > 0.05). Resting SmO2 before both MOD and SEV intensity cycling was not significantly different between conditions (MOD: HBD: 85.6 ± 1.8%, DYN: 86.4 ± 2.3%; SEV: HBD: 87.3 ± 2.4%, DYN: 87.8 ± 2.4%; p > 0.05). During MOD intensity cycling, SmO2 was not significantly different between conditions, as assessed by the area under the curve (HBD: 27,785 ± 1,348 %·s, DYN: 26,842 ± 1,821 %·s; p > 0.05). However, during SEV intensity cycling, SmO2 was significantly higher in the HBD condition compared to DYN, as assessed by the area under the curve (HBD: 23,737 ± 3,930 %·s, DYN: 18,688 ± 2,365 %·s; p < 0.05). No differences were found in HR, BP, or pulmonary oxygen uptake during exercise across conditions. CONCLUSIONS: Consistent with our hypothesis, these findings suggest that HBD prior to cycling elevates SmO2 during SEV intensity cycling but does not translate to improved exercise tolerance in healthy adults. HBD does not affect SmO2 during MOD intensity cycling in the conditions evaluated herein.