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Sodium acetate ingestion perturbs substrate utilisation at rest and during the early stages of prolonged exercise in man
Author(s) -
Smith Gordon Ian,
Jeukendrup Asker Erik,
Ball Derek
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.5.lb25-a
Subject(s) - ingestion , sodium bicarbonate , carbohydrate , chemistry , medicine , endocrinology , sodium acetate , sodium , bicarbonate , endurance training , chromatography , organic chemistry
Sodium acetate administration has been shown to increase muscle acetyl‐CoA and acetylcarnitine content at rest and during the early stages of exercise. We therefore investigated the effect of sodium acetate ingestion at rest on subsequent substrate utilisation during prolonged exercise. With local ethics approval six healthy males ingested either sodium acetate (NaAc) or sodium bicarbonate (NaHCO 3 ) at a dose of 4 mmol.kg −1 body mass in a randomised order over 90 min prior to 120 min of exercise at 50% V̇O 2max . NaAc ingestion decreased resting fat oxidation (0.09 ± 0.02 vs. 0.07 ± 0.02 g.min −1 pre‐ and post‐ingestion respectively, P<0.05) with no effect upon carbohydrate utilisation. In contrast, NaHCO 3 ingestion did not affect substrate utilisation at rest. Fat and CHO oxidation increased in both trials when exercise was undertaken, but fat oxidation was lower (0.16 ± 0.10 vs. 0.30 ± 0.10 g.min −1 , P<0.05) and carbohydrate oxidation higher (1.75 ± 0.36 vs. 1.50 ± 0.23 g.min −1 , P<0.05) in the NaAc compared with the NaHCO 3 trial during the first 15 min of exercise. Plasma acetate concentration had returned to baseline after 30 min of exercise in the NaAc trial with no difference in either fat or carbohydrate utilisation between the trials over the last 90 min of exercise. These results demonstrate that increasing plasma acetate concentration suppresses fat oxidation at rest and at the onset of exercise possibly due to changes in acetyl group availability.