title: Variable resistance training promotes greater fatigue resistance but not hypertrophy versus constant resistance training.
abstract: Loading using variable resistance devices, where the external resistance changes in line with the force:angle relationship, has been shown to cause greater acute neuromuscular fatigue and larger serum hormone responses. This may indicate a greater potential for adaptation during long-term training. Twelve (constant resistance group) and 11 (variable resistance group) men completed 20 weeks of resistance training with 10 men as non-training controls. Training-induced adaptations were assessed by bilateral leg press one repetition maximum, a repetition to failure test using 75 % 1RM, lower limb lean mass and vastus lateralis cross-sectional area. Only the variable resistance training group improved the total number of repetitions (41 ± 46 %) and volume load (52 ± 37 %) during the repetition to failure test (P < 0.05). Similar improvements in maximum strength and hypertrophy of the lower limbs were observed in both training groups. Also, constant and variable resistance 5 × 10RM leg press loadings were performed before and after training in a crossover design. Acute loading-induced responses were assessed by concentric and isometric force, serum hormone concentrations and phosphorylation of intramuscular signalling proteins (0-30 min post-loading). Greater acute decreases in force (P < 0.05-0.01), and greater increases in serum testosterone and cortisol concentration (P < 0.05) and ERK 1/2 phosphorylation (P < 0.05) were observed following variable resistance loadings before and after training. Greater training-induced improvements in fatigue resistance occurred in the variable resistance training group, which may be due to greater acute fatigue and physiological responses during variable versus constant resistance loadings.
authors: Department of Biology of Physical Activity and Neuromuscular Research Center, University of Jyväskylä, PO Box 35 (VIV), 40014 Jyväskylä, Finland. simon.walker@jyu.fi
authors: Simon
authors: S
authors: Walker
authors: Juha J
authors: JJ
authors: Hulmi
authors: Mathias
authors: M
authors: Wernbom
authors: Kai
authors: K
authors: Nyman
authors: William J
authors: WJ
authors: Kraemer
authors: Juha P
authors: JP
authors: Ahtiainen
authors: Keijo
authors: K
authors: Häkkinen
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D000328:Adult; D018592:Cross-Over Studies; D015444:Exercise / Q000502:physiology*; D005221:Fatigue / Q000097:blood / Q000473:pathology*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D006984:Hypertrophy / Q000097:blood; D007537:Isometric Contraction / Q000502:physiology; D007866:Leg / Q000502:physiology; D020935:MAP Kinase Signaling System / Q000502:physiology; D008297:Male; D018482:Muscle, Skeletal / Q000473:pathology* / Q000502:physiology; D052097:Quadriceps Muscle / Q000473:pathology; D055070:Resistance Training / Q000379:methods*; D013739:Testosterone / Q000097:blood
chemical_list: D013739:Testosterone; D006854:Hydrocortisone
references: J Appl Physiol (1985). 1990 Oct;69(4):1442-50
references: 2262468
references: Biochem J. 2004 Jun 15;380(Pt 3):795-804
references: 15030312
references: J Appl Physiol (1985). 2009 May;106(5):1720-9
references: 19299575
references: Eur J Appl Physiol. 2010 Nov;110(4):835-43
references: 20617335
references: FASEB J. 2006 Jan;20(1):190-2
references: 16267123
references: J Appl Physiol (1985). 2001 May;90(5):1936-42
references: 11299288
references: Nat Cell Biol. 2001 Nov;3(11):1009-13
references: 11715022
references: Eur J Appl Physiol. 2008 Jan;102(2):145-52
references: 17874120
references: Med Sci Sports Exerc. 1988 Oct;20(5 Suppl):S158-61
references: 3057316
references: Eur J Appl Physiol Occup Physiol. 1978 Jul 17;39(1):27-35
references: 679941
references: Appl Physiol Nutr Metab. 2006 Oct;31(5):495-501
references: 17111003
references: Am J Physiol. 1999 Jan;276(1):C120-7
references: 9886927
references: Med Sci Sports Exerc. 1983;15(6):455-60
references: 6656553
references: Scand J Med Sci Sports. 2012 Apr;22(2):240-8
references: 21204993
references: Med Sci Sports Exerc. 1990 Jun;22(3):397-401
references: 2381309
references: J Appl Physiol (1985). 1993 Feb;74(2):882-7
references: 8458810
references: J Physiol. 2008 Aug 1;586(15):3701-17
references: 18556367
references: J Electromyogr Kinesiol. 2011 Apr;21(2):262-9
references: 21251849
references: Electromyogr Clin Neurophysiol. 1988 Mar-Apr;28(2-3):79-87
references: 3416808
references: J Physiol. 2001 Aug 15;535(Pt 1):155-64
references: 11507166
references: Electromyogr Clin Neurophysiol. 1994 Mar;34(2):117-24
references: 8187678
references: Acta Physiol (Oxf). 2007 Oct;191(2):139-46
references: 17565567
references: Cardiovasc Res. 2007 Dec 1;76(3):390-9
references: 17850776
references: Med Sci Sports Exerc. 2005 Nov;37(11):1990-7
references: 16286871
references: J Sports Sci. 2003 Jan;21(1):59-71
references: 12587892
references: Eur J Appl Physiol. 2002 Nov;88(1-2):50-60
references: 12436270
references: Med Sci Sports Exerc. 2007 Oct;39(10):1817-24
references: 17909410
references: J Strength Cond Res. 2005 Nov;19(4):725-9
references: 16287364
references: Eur J Appl Physiol. 2010 Jan;108(2):273-9
references: 19777252
references: J Strength Cond Res. 2005 May;19(2):382-8
references: 15903379
references: Biophys J. 2009 Jul 8;97(1):347-56
references: 19580773
references: J Appl Physiol Respir Environ Exerc Physiol. 1977 Oct;43(4):700-3
references: 908686
references: Can J Appl Physiol. 1997 Jun;22(3):244-55
references: 9189304
references: Am J Physiol Regul Integr Comp Physiol. 2007 Apr;292(4):R1594-602
references: 17194727
references: Can J Appl Physiol. 1999 Feb;24(1):96-107
references: 9916184
references: J Appl Physiol (1985). 2008 Sep;105(3):816-24
references: 18617629
references: Mol Cell Biol. 2007 Jan;27(1):170-81
references: 17030606
references: Med Sci Sports Exerc. 2011 Jan;43(1):26-33
references: 20473217
references: J Strength Cond Res. 2008 Mar;22(2):567-74
references: 18550975
references: Electromyogr Clin Neurophysiol. 1980 Mar-Apr;20(2):159-54
references: 7379739
references: Sports Med. 2010 Apr 1;40(4):303-26
references: 20364875
references: Sports Med. 2007;37(3):225-64
references: 17326698