title: Role of exercise duration on metabolic adaptations in working muscle to short-term moderate-to-heavy aerobic-based cycle training.
abstract: This study aimed at investigating the relative roles of the duration versus intensity of exercise on the metabolic adaptations in vastus lateralis to short-term (10 day) aerobic-based cycle training. Healthy males with a peak aerobic power (VO2 peak) of 46.0 ± 2.0 ml kg(-1) min(-1) were assigned to either a 30-min (n = 7) or a 60-min (n = 8) duration performed at two different intensities (with order randomly assigned), namely moderate (M) and heavy (H), corresponding to 70 and 86 % VO2 peak, respectively. No change (P > 0.05) in VO2 peak was observed regardless of the training program. Based on the metabolic responses to prolonged exercise (60 % VO2 peak), both M and H and 30 and 60 min protocols displayed less of a decrease (P < 0.05) in phosphocreatine (PCr) and glycogen (Glyc) and less of an increase (P < 0.05) in free adenosine diphosphate (ADPf), free adenosine monophosphate (AMPf), inosine monophosphate (IMP) and lactate (La). Training for 60 min compared with 30 min resulted in a greater protection (P < 0.05) of ADPf, AMPf, PCr and Glyc during exercise, effects that were not displayed between M and H. The reduction in both VO2 and RER (P < 0.05) observed during submaximal exercise did not depend on training program specifics. These findings indicate that in conjunction with our earlier study (Green et al., Eur J Appl Physiol, 2012b), a threshold exists for duration rather than intensity of aerobic exercise to induce a greater training impact in reducing metabolic strain.
authors.affiliation: Department of Kinesiology, University of Waterloo, Waterloo, ON , N2L3G1, Canada. green@uwaterloo.ca
authors.forename: Howard J
authors.initials: HJ
authors.lastname: Green
authors.forename: Margaret
authors.initials: M
authors.lastname: Burnett
authors.forename: Sherry
authors.initials: S
authors.lastname: Carter
authors.forename: Ira
authors.initials: I
authors.lastname: Jacobs
authors.forename: Don
authors.initials: D
authors.lastname: Ranney
authors.forename: Ian
authors.initials: I
authors.lastname: Smith
authors.forename: Susan
authors.initials: S
authors.lastname: Tupling
mesh_terms: D000222:Adaptation, Physiological; D000244:Adenosine Diphosphate / Q000378:metabolism; D000249:Adenosine Monophosphate / Q000378:metabolism; D015444:Exercise; D006003:Glycogen / Q000378:metabolism; D006801:Humans; D007291:Inosine Monophosphate / Q000378:metabolism; D019344:Lactic Acid / Q000378:metabolism; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism / Q000502:physiology*; D010101:Oxygen Consumption; D010725:Phosphocreatine / Q000378:metabolism; D013997:Time Factors; D055815:Young Adult
chemical_list: D010725:Phosphocreatine; D007291:Inosine Monophosphate; D019344:Lactic Acid; D000249:Adenosine Monophosphate; D000244:Adenosine Diphosphate; D006003:Glycogen
references.citation: J Chromatogr. 1982 Jun 18;242(1):119-26
references.pmid: 7107798
references.citation: Am J Physiol Endocrinol Metab. 2012 Jun 1;302(11):E1343-51
references.pmid: 22395109
references.citation: Can J Physiol Pharmacol. 1995 Apr;73(4):474-82
references.pmid: 7671190
references.citation: J Physiol. 2010 May 15;588(Pt 10):1779-90
references.pmid: 20308248
references.citation: Am J Physiol Endocrinol Metab. 2011 Jan;300(1):E3-10
references.pmid: 21045171
references.citation: Cardiovasc Res. 1996 Feb;31(2):278-86
references.pmid: 8730405
references.citation: Am J Physiol Endocrinol Metab. 2001 Mar;280(3):E528-33
references.pmid: 11171609
references.citation: Biochem J. 2009 Mar 1;418(2):261-75
references.pmid: 19196246
references.citation: Am J Physiol Regul Integr Comp Physiol. 2011 Nov;301(5):R1350-7
references.pmid: 21849631
references.citation: Diabetes. 2003 Sep;52(9):2205-12
references.pmid: 12941758
references.citation: J Appl Physiol (1985). 1989 Jan;66(1):142-50
references.pmid: 2917917
references.citation: Acta Physiol (Oxf). 2011 Jul;202(3):225-39
references.pmid: 20946238
references.citation: J Appl Physiol (1985). 2006 Sep;101(3):695-706
references.pmid: 16709650
references.citation: Am J Physiol Regul Integr Comp Physiol. 2009 Nov;297(5):R1383-91
references.pmid: 19710384
references.citation: J Physiol. 2006 Jul 1;574(Pt 1):17-31
references.pmid: 16690705
references.citation: J Appl Physiol (1985). 1990 Mar;68(3):833-42
references.pmid: 2187852
references.citation: Acta Physiol (Oxf). 2009 May;196(1):155-74
references.pmid: 19243572
references.citation: J Physiol. 2008 Dec 15;586(24):6021-35
references.pmid: 18955383
references.citation: Scand J Clin Lab Invest. 1974 Apr;33(2):109-20
references.pmid: 4852173
references.citation: Exerc Sport Sci Rev. 2002 Jul;30(3):129-37
references.pmid: 12150572
references.citation: Pflugers Arch. 1976 Dec 28;367(2):143-9
references.pmid: 13343
references.citation: J Exp Biol. 2006 Jun;209(Pt 12):2265-75
references.pmid: 16731803
references.citation: J Appl Physiol (1985). 2009 Jul;107(1):128-38
references.pmid: 19443744
references.citation: J Appl Physiol (1985). 1996 Nov;81(5):2182-91
references.pmid: 9053394
references.citation: Muscle Nerve. 2009 Dec;40(6):918-35
references.pmid: 19902542
references.citation: Clin Physiol. 1982 Feb;2(1):1-12
references.pmid: 7201906
references.citation: Exerc Sport Sci Rev. 2008 Apr;36(2):58-63
references.pmid: 18362686
references.citation: J Physiol. 2005 Oct 15;568(Pt 2):665-76
references.pmid: 16051629
references.citation: Am J Physiol Endocrinol Metab. 2002 Mar;282(3):E688-94
references.pmid: 11832374
references.citation: Can J Physiol Pharmacol. 2012 May;90(5):557-66
references.pmid: 22471991
references.citation: J Appl Physiol (1985). 1995 Dec;79(6):1914-20
references.pmid: 8847253
references.citation: J Physiol. 2000 Oct 1;528 Pt 1:221-6
references.pmid: 11018120
references.citation: Sports Med. 2007;37(9):737-63
references.pmid: 17722947
references.citation: Exp Physiol. 2007 Sep;92(5):783-97
references.pmid: 17631518
references.citation: J Physiol. 2012 Mar 1;590(5):1069-76
references.pmid: 22199166
references.citation: J Appl Physiol (1985). 1995 Oct;79(4):1134-41
references.pmid: 8567554
references.citation: J Appl Physiol Respir Environ Exerc Physiol. 1984 Apr;56(4):831-8
references.pmid: 6373687
references.citation: J Exp Biol. 2006 Jun;209(Pt 12):2239-48
references.pmid: 16731801
references.citation: Am J Physiol. 1999 Jul;277(1):E39-48
references.pmid: 10409126
references.citation: Acta Physiol (Oxf). 2009 May;196(1):15-26
references.pmid: 19245655
references.citation: J Appl Physiol (1985). 1994 Jun;76(6):2586-93
references.pmid: 7928887
references.citation: Am J Physiol. 1996 Feb;270(2 Pt 1):E265-72
references.pmid: 8779948
references.citation: Pflugers Arch. 2010 Jun;460(1):153-62
references.pmid: 20401754
references.citation: J Appl Physiol (1985). 1992 Feb;72(2):484-91
references.pmid: 1559923
references.citation: Am J Physiol Regul Integr Comp Physiol. 2008 Jul;295(1):R264-72
references.pmid: 18417645
references.citation: Exerc Sport Sci Rev. 2009 Apr;37(2):86-92
references.pmid: 19305200
references.citation: J Biol Chem. 2009 Sep 4;284(36):23925-34
references.pmid: 19525228
references.citation: Can J Appl Sport Sci. 1980 Mar;5(1):15-8
references.pmid: 7389042
references.citation: J Physiol. 2006 Jul 1;574(Pt 1):7-15
references.pmid: 16644800
references.citation: Eur J Appl Physiol. 2013 Feb;113(2):313-24
references.pmid: 22706580