title: Mitochondrial gene expression in elite cyclists: effects of high-intensity interval exercise.
abstract: Little is known about the effect of training on genetic markers for mitochondrial biogenesis in elite athletes. We tested the hypothesis that low-volume sprint interval exercise (SIE) would be as effective as high-volume interval exercise (IE). Ten male cyclists competing on national elite level (W (max) 403 ± 13 W, VO(2peak) 68 ± 1 mL kg(-1) min(-1)) performed two interval exercise protocols: 7 × 30-s "all-out" bouts (SIE) and 3 × 20-min bouts at ~87% of VO(2peak) (IE). During IE, the work was eightfold larger (1,095 ± 43 vs. 135 ± 5 kJ) and the exercise duration 17 times longer (60 vs. 3.5 min) than during SIE. Muscle samples were taken before and 3 h after exercise. The mRNA of upstream markers of mitochondrial biogenesis [peroxisome proliferator-activated receptor-γ coactivator-1 (PGC-1α), PGC-1α-related coactivator (PRC) and peroxisome proliferator-activated receptor δ (PPARδ)] increased to the same extent after SIE and IE (6-, 1.5- and 1.5-fold increase, respectively). Of the downstream targets of PGC-1α, mitochondrial transcription factor A (Tfam) increased only after SIE and was significantly different from that after IE (P < 0.05), whereas others increased to the same extent (pyruvate dehydrogenase kinase, PDK4) or was unchanged (nuclear respiratory factor 2, NRF2). We conclude that upstream genetic markers of mitochondrial biogenesis increase in a similar way in elite athletes after one exercise session of SIE and IE. However, since the volume and duration of work was considerably lower during SIE and since Tfam, the downstream target of PGC-1α, increased only after SIE, we conclude that SIE might be a time-efficient training strategy for highly trained individuals.
authors.affiliation: Astrand Laboratory, GIH, The Swedish School of Sport and Health Sciences, Box 5626, SE 114 86 Stockholm, Sweden.
authors.forename: Niklas
authors.initials: N
authors.lastname: Psilander
authors.forename: Psilander
authors.initials: P
authors.lastname: Niklas
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.forename: Wang
authors.initials: W
authors.lastname: Li
authors.forename: Jens
authors.initials: J
authors.lastname: Westergren
authors.forename: Westergren
authors.initials: W
authors.lastname: Jens
authors.forename: Michail
authors.initials: M
authors.lastname: Tonkonogi
authors.forename: Tonkonogi
authors.initials: T
authors.lastname: Michail
authors.forename: Kent
authors.initials: K
authors.lastname: Sahlin
authors.forename: Sahlin
authors.initials: S
authors.lastname: Kent
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D000328:Adult; D056352:Athletes; D001642:Bicycling; D004268:DNA-Binding Proteins / Q000235:genetics; D005080:Exercise Test; D015870:Gene Expression / Q000235:genetics*; D050259:Genes, Mitochondrial / Q000235:genetics*; D006360:Heat-Shock Proteins / Q000235:genetics; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D008928:Mitochondria / Q000502:physiology*; D024101:Mitochondrial Proteins / Q000235:genetics; D051267:NF-E2-Related Factor 2 / Q000235:genetics; D010101:Oxygen Consumption / Q000502:physiology; D047495:PPAR gamma / Q000235:genetics; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D005082:Physical Exertion / Q000502:physiology*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics; D000081382:Pyruvate Dehydrogenase Acetyl-Transferring Kinase; D052097:Quadriceps Muscle / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics; D015854:Up-Regulation / Q000235:genetics; D055815:Young Adult
chemical_list: D004268:DNA-Binding Proteins; D006360:Heat-Shock Proteins; D024101:Mitochondrial Proteins; D051267:NF-E2-Related Factor 2; C495635:NFE2L2 protein, human; C000631432:PDK4 protein, human; D047495:PPAR gamma; C486497:PPARGC1A protein, human; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D000081382:Pyruvate Dehydrogenase Acetyl-Transferring Kinase; C499631:TFAM protein, human; D014157:Transcription Factors; C111264:peroxisome-proliferator-activated receptor-gamma coactivator-1; D019344:Lactic Acid; D017346:Protein Serine-Threonine Kinases