Sodium bicarbonate ingestion augments the increase in PGC-1α mRNA expression during recovery from intense interval exercise in human skeletal muscle

• Published in: Journal of applied physiology (1985) Vol. 119; no. 11; pp. 1303 - 1312
• Main Authors: Percival, Michael E., Martin, Brian J., Gillen, Jenna B., Skelly, Lauren E., MacInnis, Martin J., Green, Alex E., Tarnopolsky, Mark A., Gibala, Martin J.
• Format: Journal Article
• Language: English
• Published: United States American Physiological Society 01.12.2015
• Subjects: Adult; Bicarbonates - blood; Cross-Over Studies; Double-Blind Method; Exercise - physiology; Glycogen - metabolism; Heart Rate - physiology; Humans; Male; Mitochondria, Muscle - metabolism; Muscle, Skeletal - metabolism; p38 Mitogen-Activated Protein Kinases - biosynthesis; p38 Mitogen-Activated Protein Kinases - genetics; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; Phosphorylation; RNA, Messenger - biosynthesis; Sodium Bicarbonate - pharmacology; Transcription Factors - biosynthesis; Young Adult; high-intensity interval training; supplementation; glycogen; mitochondria
• ISSN: 8750-7587; 1522-1601
• DOI: 10.1152/japplphysiol.00048.2015

We tested the hypothesis that ingestion of sodium bicarbonate (NaHCO 3 ) 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 NaHCO 3 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 NaHCO 3 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 NaHCO 3 in rats.