Abstract des Autors

The effects of sodium bicarbonate and sodium citrate ingestion on 600 m running performance were assessed in 11 female track athletes and four trained female non-athletes. The subjects ingested either sodium bicarbonate (NaHCO3), sodium citrate or placebo approximately 2.5 hrs prior to the test runs in doses of 0.3 g/kg body weight in a double blind cross over design. Prior to and after exercise NaHCO3, H+, and lactate (HLa) concentrations were measured and running times were recorded. Pre- and post-experiment baseline testings were also performed. Data analysis was conducted using a Manova Repeated Measures design and dependent "t"-test. Although differences in running times were found 121.5 s, 119.9 s, 120.4 s in bicarbonate, citrate and placebo treatments respectively, they were not significant. The pH and concentrations of NaHCO3 were significantly elevated prior to and after the exercise when alkalinizing agents were ingested (p<0.001). In bicarbonate treatment, prior to exercise pH was 7.40 and [NaHCO3] was 28.4 mEq/l, and after the exercise pH was 7.14 and [NaHCO3] was 17.9 mEq/l. In citrate treatment, prior to exercise pH was 7.40 and [NaHCO3] was 27.1 mEq/l, and after the exercise pH was 7.13 and [NaHCO3] was 16.6 mEq/l. There were no significant differences among the pre-exercise (2.3 mmol/l, 2.1 mmol/1, 2.2 mmol/l in bicarbonate, citrate and placebo treatments respectively) and after-exercise (11.8 mmol/l, 11.9 mmol/l, 11.0 mmol/l bicarbonate, citrate and placebo, respectively) HLa concentrations. This study demonstrated that, although alkali ingestion resulted in significant shifts in the blood acid-base balance, it failed to affect the 600 m running performance. Verf.-Referat