title: Sodium bicarbonate ingestion augments the increase in PGC-1α mRNA expression during recovery from intense interval exercise in human skeletal muscle.
abstract: We tested the hypothesis that ingestion of sodium bicarbonate (NaHCO3) prior to an acute session of high-intensity interval training (HIIT) would augment signaling cascades and gene expression linked to mitochondrial biogenesis in human skeletal muscle. On two occasions separated by ∼1 wk, nine men (mean ± SD: age 22 ± 2 yr, weight 78 ± 13 kg, V̇O(2 peak) 48 ± 8 ml·kg(-1)·min(-1)) performed 10 × 60-s cycling efforts at an intensity eliciting ∼90% of maximal heart rate (263 ± 40 W), interspersed with 60 s of recovery. In a double-blind, crossover manner, subjects ingested a total of 0.4 g/kg body weight NaHCO3 before exercise (BICARB) or an equimolar amount of a placebo, sodium chloride (PLAC). Venous blood bicarbonate and pH were elevated at all time points after ingestion (P < 0.05) in BICARB vs. PLAC. During exercise, muscle glycogen utilization (126 ± 47 vs. 53 ± 38 mmol/kg dry weight, P < 0.05) and blood lactate accumulation (12.8 ± 2.6 vs. 10.5 ± 2.8 mmol/liter, P < 0.05) were greater in BICARB vs. PLAC. The acute exercise-induced increase in the phosphorylation of acetyl-CoA carboxylase, a downstream marker of AMP-activated protein kinase activity, and p38 mitogen-activated protein kinase were similar between treatments (P > 0.05). However, the increase in PGC-1α mRNA expression after 3 h of recovery was higher in BICARB vs. PLAC (approximately sevenfold vs. fivefold compared with rest, P < 0.05). We conclude that NaHCO3 before HIIT alters the mRNA expression of this key regulatory protein associated with mitochondrial biogenesis. The elevated PGC-1α mRNA response provides a putative mechanism to explain the enhanced mitochondrial adaptation observed after chronic HIIT supplemented with NaHCO3 in rats.
authors.affiliation: Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada; and.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Percival
authors.affiliation: Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada; and.
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Martin
authors.affiliation: Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada; and.
authors.forename: Jenna B
authors.initials: JB
authors.lastname: Gillen
authors.affiliation: Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada; and.
authors.forename: Lauren E
authors.initials: LE
authors.lastname: Skelly
authors.affiliation: Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada; and.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: MacInnis
authors.affiliation: Department of Pediatrics and Medicine, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Alex E
authors.initials: AE
authors.lastname: Green
authors.affiliation: Department of Pediatrics and Medicine, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Tarnopolsky
authors.affiliation: Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada; and gibalam@mcmaster.ca.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Gibala
mesh_terms: D000328:Adult; D001639:Bicarbonates / Q000097:blood; D018592:Cross-Over Studies; D004311:Double-Blind Method; D015444:Exercise / Q000502:physiology*; D006003:Glycogen / Q000378:metabolism; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008931:Mitochondria, Muscle / Q000378:metabolism; D018482:Muscle, Skeletal / Q000378:metabolism; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D010766:Phosphorylation; D012333:RNA, Messenger / Q000096:biosynthesis*; D017693:Sodium Bicarbonate / Q000494:pharmacology*; D014157:Transcription Factors / Q000096:biosynthesis*; D055815:Young Adult; D048051:p38 Mitogen-Activated Protein Kinases / Q000096:biosynthesis / Q000235:genetics
chemical_list: D001639:Bicarbonates; C486497:PPARGC1A protein, human; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D012333:RNA, Messenger; D014157:Transcription Factors; D017693:Sodium Bicarbonate; D006003:Glycogen; D048051:p38 Mitogen-Activated Protein Kinases
keywords: glycogen; high-intensity interval training; mitochondria; supplementation