Author(s): RAMOS-ALMEIDA, F., DE NIGRIS, E.1, GARCIA-GONZALEZ, E.1, GARCIA-PEREZ, G.1, GALVAN-ALVAREZ, V.1, MARTINEZ-CANTON, M.1, RAPAZZETI, L.1, VAL-BISPO, D.1, MARTIN-RINCON, M.1, CALBET, J.A.L.1,2 , Institution: UNIVERSIDAD DE LAS PALMAS DE GRAN CANARIA, Country: SPAIN, Abstract-ID: 2723

INTRODUCTION:
High-intensity interval training is a time-efficient strategy widely used to improve performance and fitness. We previously showed that brief vascular occlusion applied at exhaustion prolongs intracellular signalling and increases antioxidant capacity, responses that depend on muscle oxygenation and metabolite accumulation during recovery from intense exercise. Imposing ischaemia during recovery may therefore prolong cellular stress and potentiate training adaptations. This study tested whether adding post-exercise ischaemia to high-intensity interval training (HIIT) enhances physiological and performance adaptations.
METHODS:
Nineteen physically active males completed a 12-wk HIIT (3 d/wk; intervals at 85–100% of VO₂max). Participants were randomised to free circulation (CON) or ischaemic recovery (OCLU) with matched training volume. In OCLU, each recovery began with cycling with total vascular occlusion (5–10 s), extended for 20-50s while the subjects rested on the bike. Before and after training, participants performed an incremental test, repeated exercise at 120% VO₂max to assess the functional reserve, a double Wingate separated by 20-s occlusion, a 6-min performance test, and DEXA. Statistics: two-way mixed ANOVA.
RESULTS:
VO₂max increased in both groups (p<0.001) with similar gains in OCLU (+9.8%) and CON (+7.7%) without interaction. Wmax also increased similarly (p<0.001), including LLM-normalised values (+16.8% vs +6.3%). During the first bout at 120% VO₂max, TTE increased similarly (+71.5% vs +70.5%, p<0.001). Work·kg LLM⁻¹ increased markedly (+68.6% and +74.2%, p<0.001), attained VO₂ rose (~10–14%, p<0.001), and anaerobic contribution decreased (~−34%, p<0.05). Ventilatory responses differed: VE/VCO₂ increased in OCLU but decreased in CON (interaction p=0.011), whereas PETCO₂ decreased in OCLU but increased in CON (interaction p=0.013). The functional reserve improved, with work·kg LLM⁻¹ increasing +22.9% (OCLU) and +12.9% (CON) (p=0.001) without interaction; absolute work rose similarly (~23–26%, p<0.001) and O₂ deficit was unchanged (p>0.05). Double Wingate performance improved, especially bout 2 (p<0.05). Mean power and total work increased (p<0.001), whereas peak power did not (p>0.05). Six-min performance increased similarly (~13%, p<0.01) with reduced HRmean (p<0.05). Body composition showed interactions: fat mass ↓ and lean mass ↑ in OCLU but not CON (p<0.05).
CONCLUSION:
HIIT improved aerobic capacity and high-intensity performance irrespective of recovery condition. These data provide experimental evidence that functional reserve is trainable. The absence of additional performance gains with post-exercise ischaemia indicates that the additional stimulus was insufficient to further enhance the adaptation to HIIT. Differential ventilatory responses and reduced anaerobic contribution may reflect a shift toward a more oxidative phenotype.

PDC2025-165723-I00; CSD (EXP_75097); SD-24/03 (ID 877) CUCIC.