title: Divergent response of metabolite transport proteins in human skeletal muscle after sprint interval training and detraining.
abstract: Skeletal muscle primarily relies on carbohydrate (CHO) for energy provision during high-intensity exercise. We hypothesized that sprint interval training (SIT), or repeated sessions of high-intensity exercise, would induce rapid changes in transport proteins associated with CHO metabolism, whereas changes in skeletal muscle fatty acid transporters would occur more slowly. Eight active men (22 +/- 1 yr; peak oxygen uptake = 50 +/- 2 ml.kg(-1).min(-1)) performed 4-6 x 30 s all-out cycling efforts with 4-min recovery, 3 days/wk for 6 wk. Needle muscle biopsy samples (vastus lateralis) were obtained before training (Pre), after 1 and 6 wk of SIT, and after 1 and 6 wk of detraining. Muscle oxidative capacity, as reflected by the protein content of cytochrome c oxidase subunit 4 (COX4), increased by approximately 35% after 1 wk of SIT and remained higher compared with Pre, even after 6 wk of detraining (P < 0.05). Muscle GLUT4 content increased after 1 wk of SIT and remained approximately 20% higher compared with baseline during detraining (P < 0.05). The monocarboxylate tranporter (MCT) 4 was higher after 1 and 6 wk of SIT compared with Pre, whereas MCT1 increased after 6 wk of training and remained higher after 1 wk of detraining (P < 0.05). There was no effect of training or detraining on the muscle content of fatty acid translocase (FAT/CD36) or plasma membrane associated fatty acid binding protein (FABPpm) (P > 0.05). We conclude that short-term SIT induces rapid increases in skeletal muscle oxidative capacity but has divergent effects on proteins associated with glucose, lactate, and fatty acid transport.
authors.affiliation: Exercise Metabolism Research Group, Dept of Kinesiology, McMaster Univ, Hamilton, Ontario, Canada.
authors.forename: Kirsten A
authors.initials: KA
authors.lastname: Burgomaster
authors.forename: Naomi M
authors.initials: NM
authors.lastname: Cermak
authors.forename: Stuart M
authors.initials: SM
authors.lastname: Phillips
authors.forename: Carley R
authors.initials: CR
authors.lastname: Benton
authors.forename: Arend
authors.initials: A
authors.lastname: Bonen
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Gibala
mesh_terms: D002352:Carrier Proteins / Q000378:metabolism*; D015444:Exercise / Q000502:physiology*; D005786:Gene Expression Regulation; D006801:Humans; D008297:Male; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism; D018482:Muscle, Skeletal / Q000378:metabolism*; D013997:Time Factors
chemical_list: D002352:Carrier Proteins; D009124:Muscle Proteins