Tabriz University of Medical Sciences Medical Journal of Tabriz University of Medical Sciences 2783-2031 35 3 2013 08 05 Comparison the Effect of Two Chronic and Acute Loading of Sodium Bicarbonate Supplementation on Fatigue and Performance Indices after Exhaustive Aerobic Activity in Active Men 40 45 EN Asgar Tofighi Saber Saedmocheshi Journal Article 2012 11 23 2013 03 02 Backgrounds and Objectives: Approach of supplementation usage and its effect on fatigue retarding had been attention of athletes and coaches. The aim of this study was to comparison the acute and chronic loading of sodium bicarbonate supplement on fatigue and performance indices after exhaustive aerobic activity in active men. Materials and Methods: 10 active men were selected and assign to experimental group. The participants had taken sodium bicarbonate supplement in two forms of acute and chronic loading. For determine the amount of lactate production and blood PH, blood samples were taken in four stages including’s before exercise and after either supplementation method usage and also immediately after exercise test. Modified BRUCE moderate-intensity test were done up to 75% of maximum heart rate as exercise test. Results: The result showed that bicarbonate supplement in form of chronic loading inhibits blood lactate accumulation significantly. Compared with acute model, chronic loading of sodium bicarbonate increased the duration of activity and blood PH up to 26 percent (P<0/05). Conclusion: It seems that chronic loading of sodium bicarbonate by improving the buffering capacity increase the amount of blood PH and retarding the fatigue period and induces the much time of activity.