Work

Dietary nitrate supplementation very slightly mitigates the oxidative stress induced by high-intensity training performed in normobaric hypoxia

Year: 2024

Type: article

Abstract: Oxidative stress is augmented under hypoxic environments, which may be attenuated with antioxidant supplementation.We investigated the effects of dietary nitrate (NO 3 -) supplementation combined with high-intensity training performed under hypoxic conditions on antioxidant/pro-oxidant balance.Thirty trained participants were assigned to one of three groups -HNO: hypoxia (13% F i O 2 ) + NO 3 -; HPL: hypoxia + placebo; CON: normoxia (20.9% F i O 2 ) + placebo -while performing 12 cycling high-intensity interval training (HIIT) sessions during a 4-week period (3 sessions/week).Before and after the intervention, venous blood samples were collected and a time to exhaustion test (T lim ) was performed (with vastus lateralis changes in local O 2 saturation: SmO 2 monitoring).Glutathione peroxidase (GPX) activity increased in CON (p = 0.017, ~20%) and superoxide dismutase (SOD), catalase and ferric-reducing antioxidant power (FRAP) did not change in any group.Malondialdehydes (MDA) increased in both HNO (p = 0.001, ~60%) and CON (p = 0.023, ~30%) but not in HPL.Advanced oxidation protein products (AOPP), uric acid, and myeloperoxidase activity were not modified by the protocol.Only the CON group recovered faster after the T lim test (SmO 2recovery : p = 0.0003, ~58%).Hypoxic exposure during high-intensity training blunted the increase in GPX and MDA after the intervention period.However, the effects of NO 3 -supplementation seem to very slightly mitigate the detrimental effect of performing high-intensity training under hypoxic conditions.

Source: Biology of Sport

DOI: 10.5114/biolsport.2025.139851