THE EFFECT OF AMMONIUM-CHLORIDE AND SODIUM-BICARBONATE INGESTION ON THE PHYSICAL WORKING CAPACITY AT THE FATIGUE THRESHOLD

The purpose of this investigation was to examine the effect of ammonium chloride (NH4Cl) and sodium bicarbonate (NaHCO3) ingestion on the physical working capacity at the fatigue threshold (PWC(FT)). Eighteen adult males (mean age, SD = 23, 2 years) volunteered for two experiments (experiment 1, n = 9; experiment 2, n = 9). In both experiments, the subjects orally ingested 0.3 g.kg-1 body weight of NH4Cl and NaHCO3 over a 3-h period in random order on days separated by 72 h or more. In experiment 1, following ingestion of the substance, the subjects performed a discontinuous incremental cycle ergometer test to the onset of PWC(FT) which was estimated from integrated electromyography voltages at the vastus lateralis muscle. In experiment 2, the subjects performed a continuous PWC(FT) test. The results of these experiments indicated that NH4Cl and NaHCO3 ingestion had no significant (P > 0.05) effect on PWC(FT) (experiment 1: NH4Cl = 257, SD 26 W; NaHCO3 = 256, SD 22 W; t = 0.06; r = 0.866; experiment 2: NH4Cl = 231, 14 W; NaHCO3 = 216, 16 W; t = 1.78; r = 0.857).