Effects of bicarbonate on oxyhaemoglobin desaturation and exercise performance in athletes

Aim. Decrease in peripheral oxygen delivery may impact exercise performance in athletes with exercise-related arterial oxygen desaturation (ERD). We evaluated whether sodium bicarbonate ingestion would be effective to reduce ERD and what is the consequences upon exercise performance.Methods. Seventy highly trained athletes performed an incremental treadmill cardiopulmonary exercise test (incCPX) and a high intensity constant speed test (ctCPX) on separate days. Subjects who developed ERD by pulse oximetry were randomly allocated to oral sodium bicarbonate or placebo during 5 days. At the end of treatment subjects repeated both tests.Results. ERD prevalence was 33% during the incCPX (17 % severe, 48% moderate and 35% mild) and 34% (5 % severe, 37% moderate and 58% mild) in the ctCPX. Athletes who developed ERD have greater aerobic capacity (incCPX) and endurance time (ctCPX). Active treatment, but not placebo, reduced ERD during ctCPX (P0.05).Conclusion. Sodium bicarbonate was effective in lessening ERD during ctCPX in athletes. However, this intervention failed to improve maximal and submaximal exercise capacity in these subjects.FINEPMinisterio do Esporte (Brazil)Fed Univ Sao Paulo UNIFESP, Dept Exercise Physiol, Sao Paulo, BrazilUniv Fed Rio Grande do Sul, Porto Alegre, RS, BrazilFed Univ Sao Paulo UNIFESP, Div Resp & Crit Care, Sao Paulo, BrazilFed Univ Sao Paulo UNIFESP, Dept Exercise Physiol, Sao Paulo, BrazilFed Univ Sao Paulo UNIFESP, Div Resp & Crit Care, Sao Paulo, BrazilWeb of Scienc