title: Effect of NaHCO3 on lactate kinetics in forearm muscles during leg exercise in man.
abstract: We investigated NaHCO3 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 NaHCO3 (2 mEq.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. NaHCO3 significantly increased arterial bicarbonate concentration and pH during rest (P < 0.001; P < 0.001) and the FV test (P < 0.001; P < 0.05). During the test, [LA]A and [LA]V were significantly higher with NaHCO3 (P < 0.05, P < 0.001). At test onset, [LA]A-V became positive and increased until the braking force of 6 kg, with NaHCO3 and placebo, with values significantly lower for NaHCO3 (P < 0.001). Peak anaerobic power (Wanae, peak) and the corresponding braking force (Fmax) were also determined. Fmax was significantly increased with NaHCO3 (P < 0.001). In conclusion, the increasing rise in [LA]A and [LA]V induced by NaHCO3 may be partly explained by a decreased rate of lactate uptake by forearm skeletal muscles. NaHCO3 did not improve Wanae, peak, but improved Fmax, thus increasing FV duration.
authors.affiliation: Laboratoire de Physiologie des Interactions, Hôpital Arnaud de Villeneuve, Montpellier, France.
authors.forename: P L
authors.initials: PL
authors.lastname: Granier
authors.forename: H
authors.initials: H
authors.lastname: Dubouchaud
authors.forename: B M
authors.initials: BM
authors.lastname: Mercier
authors.forename: J G
authors.initials: JG
authors.lastname: Mercier
authors.forename: S
authors.initials: S
authors.lastname: Ahmaidi
authors.forename: C G
authors.initials: CG
authors.lastname: Préfaut
mesh_terms: D000328:Adult; D018592:Cross-Over Studies; D004311:Double-Blind Method; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005542:Forearm / Q000502:physiology; D006801:Humans; D007262:Infusions, Intravenous; D019344:Lactic Acid / Q000097:blood*; D007866:Leg; D008297:Male; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism*; D017693:Sodium Bicarbonate / Q000494:pharmacology*
chemical_list: D019344:Lactic Acid; D017693:Sodium Bicarbonate