The effects of sodium citrate on repeated maximal cycling bouts

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<strong>The</strong> <strong>effects</strong> <strong>of</strong> <strong>sodium</strong> <strong>citrate</strong> on repeated maximal cycling bouts M.J. Crowe* James Cook University, Townsville, Australia <strong>The</strong>re was no effect <strong>of</strong> <strong>sodium</strong> <strong>citrate</strong> ingestion on the peak blood lactate concentration when compared to the placebo (p > 0.05). Furthermore, there was no significant increase in peak blood lactate between baseline testing and repeat testing for the subjects in the <strong>sodium</strong> <strong>citrate</strong> group (p > 0.05). However, when the <strong>sodium</strong> <strong>citrate</strong> and placebo subjects were grouped together, there was a significant increase in peak blood lactate from 12.8 ± 3.0 mmol/l at the initial baseline testing session to 14.5 ± 3.5 mmol/l at the repeat testing session (p = 0.033; see Figure 1). Sodium <strong>citrate</strong> is <strong>of</strong>ten used in preference to <strong>sodium</strong> bicarbonate because <strong>of</strong> a reported lower incidence <strong>of</strong> gastrointestinal discomfort (Linderman & Fahey, 1991). It was therefore interesting to note that 6 <strong>of</strong> the 10 subjects who consumed <strong>sodium</strong> <strong>citrate</strong> in this study reported mild to moderate diarrhoea. <strong>The</strong> <strong>sodium</strong> <strong>citrate</strong> was delivered to the subjects in 600 ml <strong>of</strong> cordial-flavoured water. It may be possible that this was insufficient fluid to avoid the gastrointestinal upset experienced by the subjects. Although the findings <strong>of</strong> this study are in contrast to those <strong>of</strong> Hausswirth et al. (1995) and Linossier et al. (1997) who reported an ergogenic effect <strong>of</strong> <strong>sodium</strong> <strong>citrate</strong> on short-term, intense exercise, they are consistent with the findings <strong>of</strong> Cox and Jenkins (1994), Ibanez et al. (1995) and Potteiger et al. (1996) who found no ergogenic effect <strong>of</strong> 0.5 g/kg oral <strong>sodium</strong> <strong>citrate</strong> on short-term, intense exercise. In contrast to Potteiger (1996) and Ibanez et al. (1995), however, is the fact that blood lactate levels were no higher as a result <strong>of</strong> taking <strong>sodium</strong> <strong>citrate</strong>. Sodium <strong>citrate</strong> is known to alkalise the blood (Tiryaki & Atterbom, 1995; Potteiger et al., 1996; Ball & Maughan, 1997) facilitating a pH gradient to draw H + ions and lactate from the muscle compartment into the blood. Sodium <strong>citrate</strong> does not alkalise the muscle compartment with a 90 minute absorption time at a dose <strong>of</strong> 0.5 g/kg body weight (Linossier et al., 1997). Thus, it is unlikely that the muscle compartment would have been alkalised in this study. Under these conditions, <strong>sodium</strong> <strong>citrate</strong> can only reduce muscle acidosis by drawing H + and lactate from the muscle cytosol into the blood. However, this is unlikely to have happened here as higher blood lactate levels were not recorded with <strong>sodium</strong> <strong>citrate</strong>, nor were peak power or total work elevated as would be expected with increased removal <strong>of</strong> H + from the muscle compartment. <strong>The</strong> subjects in this study were reasonably anaerobically trained reaching average post-exercise blood lactate levels <strong>of</strong> 13.6 ± 3.3 mmol/l, concentrations that would be correlated with a significant drop in pH (not measured here). Thus, if <strong>sodium</strong> <strong>citrate</strong> were an effective buffer able to augment the natural buffers <strong>of</strong> the body, it would have been expected to show some effect here. Conclusions <strong>The</strong> results <strong>of</strong> this study showed that a 0.5 g/kg body weight dose <strong>of</strong> <strong>sodium</strong> <strong>citrate</strong> had no ergogenic effect on male and female subjects performing three maximal 30 s cycling bouts compared to a placebo. Peak blood lactate concentrations were also unaffected by this dose <strong>of</strong> <strong>sodium</strong> <strong>citrate</strong> under these conditions. Print Index Table <strong>of</strong> Contents Quit
References <strong>The</strong> <strong>effects</strong> <strong>of</strong> <strong>sodium</strong> <strong>citrate</strong> on repeated maximal cycling bouts M.J. Crowe* James Cook University, Townsville, Australia Ball, D. & Maughan, R. J. (1997) <strong>The</strong> effect <strong>of</strong> <strong>sodium</strong> <strong>citrate</strong> ingestion on the metabolic response to intense exercise following diet manipulation in man. Exp. Physiol. 82(6): 1041-1056. Cox, G. & Jenkins, D. G. (1994) <strong>The</strong> physiological and ventilatory responses to repeated 60 s sprints following <strong>sodium</strong> <strong>citrate</strong> ingestion. J. Sports. Sci. 12(5): 469-475. Hausswirth. C., Bigard, A. X., Lepers, R., Berthelot, M. & Guezennec, C. Y. (1995) Sodium <strong>citrate</strong> ingestion and muscle performance in acute hypobaric hypoxia. Eur. J. Appl. Physiol. 71(4): 362-368. Ibanez, J., Pullinen, T., Gorostiaga, E., Postigo, A. & Mero, A. (1995) Blood lactate and ammonia in short-term anaerobic work following induced alkalosis. J. Sports Med. Phys. Fitness. 35(3): 187-193. Linderman, J. K. & Fahey, T. D. (1991) Sodium bicarbonate ingestion and exercise performance: an update. Sports Med. 11: 71-77. Linossier, M. T., Dormois, D., Bregere, P., Geyssant, A. & Denis, C. (1997) Effect <strong>of</strong> <strong>sodium</strong> <strong>citrate</strong> on performance and metabolism <strong>of</strong> human skeletal muscle during supramaximal cycling exercise. Eur. J. Appl. Physiol. 76(1): 48-54. McNaughton, L. & Cedero, R. (1992). Sodium <strong>citrate</strong> ingestions and its <strong>effects</strong> on maximal anaerobic exercise <strong>of</strong> different durations. Eur. J. Appl. Physiol. 64(1): 36-41. Parry-Billings, M. & MacLaren, D. P. (1986) <strong>The</strong> effect <strong>of</strong> <strong>sodium</strong> bicarbonate and <strong>sodium</strong> <strong>citrate</strong> ingestion on anaerobic power during intermittent exercise. Eur. J. Appl. Physiol. 55(5): 524-529. Potteiger, J. A., Webster, M. J., Nickel, G. L., Haub, M. D. & Palmer, R. J. (1996) <strong>The</strong> <strong>effects</strong> <strong>of</strong> buffer ingestion on metabolic factors related to distance running performance. Eur. J. Appl. Physiol. 72(4): 365-371. Tiryaki, G. R. & Atterbom, H. A. (1995) <strong>The</strong> <strong>effects</strong> <strong>of</strong> <strong>sodium</strong> bicarbonate and <strong>sodium</strong> <strong>citrate</strong> on 600 m running time <strong>of</strong> trained females. J. Sports Med. Phys. Fitness. 35(3): 194-198. van Someren, K., Fulcher, K., McCarthy, J., Moore, J., Horgan, G. & Langford, R. (1998) An investigation into the <strong>effects</strong> <strong>of</strong> <strong>sodium</strong> <strong>citrate</strong> ingestion on high-intensity exercise performance. Int. J. Sports Nutr. 8(4): 356-363. Print Index Table <strong>of</strong> Contents Quit
Page 1 and 2: Introduction The <
Page 3 and 4: The effect
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