ABSTRACT
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 (P<0.05). However, there were no significant positive effects on main parameters of aerobic function and endurance exercise capacity (P>0.05). 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.
