Effect of NaHCO3 on lactate kinetics in forearm muscles during leg exercise in man
Granier, P.L.; Dubouchaud, H.; Mercier, B.M.; Mercier, J.G.; Ahmaidi, S.; Préfaut, C.G.
Medicine and Science in Sports and Exercise 28(6): 692-697
1996
ISSN/ISBN: 0195-9131 PMID: 8784757 Document Number: 460870
We investigated NaHCO-3 infusion effects on plasma lactate removal by forearm muscles and performance during intensive leg exercise. Seven subjects performed the force-velocity (FV) test with placebo and NaHCO-3 (2 mEq cntdot min-1) with a double-blind crossover protocol. Blood samples for arterial ((LA)-A) and venous ((LA)-V) lactate determinations were taken 1) at rest before infusion, and 2, 6, 10, 14, 18, and 22 min following its start; and 2) at the end of each exercise bout. The arteriovenous difference ((LA)-A-V) was determined for each sampling. NaHCO-3 significantly increased arterial bicarbonate concentration and pH during rest (P lt 0.001; P lt 0.001) and the FV test (P lt 0.001; P lt 0.05). During the test, (LA)-A and (LA)-V were significantly higher with NaHCO-3 (P lt 0.05, P lt 0.001). At test onset, (LA)-A-V became positive and increased until the braking force of 6 kg, with NaHCO-3 and placebo, with values significantly lower for NaHCO-3 (P lt 0.001). Peak anaerobic power (W-anae, peak) and the corresponding braking force (F-max) were also determined. F-max was significantly increased with NaHCO-3 (P lt 0.001). In conclusion, the increasing rise in (LA)-A and (LA)-V induced by NaHCO-3 may be partly explained by a decreased rate of lactate uptake by forearm skeletal muscles. NaHCO-3 did not improve W-anae, peak but improved F-max, thus increasing FV duration.