EFFECT OF INGESTED SODIUM-BICARBONATE ON MUSCLE FORCE, FATIGUE, AND RECOVERY

The influence of acute ingestion of NaHCO3 on fatigue and recovery of the quadriceps femoris muscle after exercise was studied in six health y male subjects. A bicycle ergometer was used far exercising under thr ee loading conditions: test A, load corresponding to maximal oxygen co nsumption; test B, load in test A + 17%; test C, load in test B but pe rformed 1 h after acute ingestion of NaHCO3. Functional electrical sti mulation (FES) was applied to provoke isometric contraction of the qua driceps femoris. The resulting knee torque was monitored during fatigu e (2-min chronic FES) and recovery (10-s FES every 10 min, for 40 min) . Quadriceps torques were higher in the presence of NaHCO3 (P < 0.05): with NaHCO3 the peak, residual, and recovery (after 40 min) normalize d torques were, respectively, 0.68 +/- 0.05 (SD), 0.58 +/- 0.05, and 0 .73 +/- 0.05; without NaHCO3 the values were 0.45 +/- 0.04, 0.30 +/- 0 .06, and 0.63 +/- 0.06. The increased torques obtained after acute ing estion of NaHCO3 indicate the possible existence of improved nonoxidat ive glycolysis in isometric contraction, resulting in reduced fatigue and enhanced recovery.