title: Influence of exercise intensity in older persons with unchanged habitual nutritional intake: skeletal muscle and endocrine adaptations.
abstract: Long-term adherence to training programmes is difficult to attain. Yet, the benefits of exercise to general health and well-being are undeniable. Any measure to demonstrate the minimum required exercise for maximal benefit to a person is a promising avenue towards increasing the uptake and adherence to physical activity for the general public. The purpose of this study was to compare the effects of two different intensities of resistance training in healthy older adults. We hypothesised that compared to high-intensity resistance exercise, relatively low training intensity could also improve in vivo markers of healthy physiologic and endocrine functions in previously sedentary older individuals. Thirty (out of a possible 34 recruited) older adults were randomly assigned to low (LowR, i.e. approximately 40% one repetition maximum (1RM)) versus high-resistance training (HighR, i.e. approximately 80% 1RM) for 12 weeks. Neither intervention significantly impacted upon body composition markers including: body mass index (BMI), waist/hip ratio and bioelectric impedance. Muscle strength data showed an advantage for the HighR protocol with 51 +/- 4% and 22.4 +/- 10.2% (P < 0.05) improvements in 1RM strength and bilateral knee extension torque, respectively, compared with 17 +/- 1% and 10.3 +/- 4.7% (P < 0.05) increments in 1RM strength and bilateral torque in the LowR group. Unilateral torque did not change significantly in either group. Quadriceps muscle thickness data also showed a significantly greater benefit of the HighR protocol (5.8 +/- 2.6% increase) compared with the LowR protocol (no change). Functional ability tests, including Get-up-and-go (GUG), Standing from lying and the 6-min walk, showed changes of -11.6 +/- 4.8%, -15.6% and 8.5 +/- 1.7% (P < 0.05), respectively, in HighR compared with only one significant improvement in the LowR, namely a -10.8 +/- 3% (P < 0.05) improvement in the GUG test. Overnight fasting serum levels of IGFBP-3 increased, NPY decreased and TNF-alpha decreased significantly in the LowR group. Serum levels of glucose increased and NPY decreased significantly in HighR. Circulating levels of I, IL-6 and IGF-1 did not change with either intervention. In vivo physiologic changes show functional advantages for older persons carrying out high-resistance training. At the endocrine level, such an advantage is not clear. In fact, in terms of changes in sera levels of fasting glucose, IGFBP-3 and TNF-alpha, there appears to be an advantage to carrying out the lower intensity exercises for the aged populations where endocrine adaptations are key.
authors.affiliation: Department of Exercise and Sport Science, Manchester Metropolitan University, Hassall Road, Alsager ST7 2HL, UK. g.pearson@mmu.ac.uk
authors.forename: Gladys Leopoldine
authors.initials: GL
authors.lastname: Onambélé-Pearson
authors.forename: Leigh
authors.initials: L
authors.lastname: Breen
authors.forename: Claire E
authors.initials: CE
authors.lastname: Stewart
mesh_terms: D000222:Adaptation, Physiological; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism*; D002149:Energy Intake; D015444:Exercise; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000378:metabolism*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D015850:Interleukin-6 / Q000378:metabolism*; D007717:Knee / Q000502:physiology; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism*; D012399:Rotation; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
chemical_list: D001786:Blood Glucose; D018972:Insulin-Like Growth Factor Binding Protein 3; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D007334:Insulin-Like Growth Factor I
references.citation: Gerontology. 2000 Sep-Oct;46(5):249-57
references.pmid: 10965180
references.citation: Z Gerontol Geriatr. 1999 Dec;32(6):425-32
references.pmid: 10654381
references.citation: Am J Clin Nutr. 1991 Apr;53(4):821-5
references.pmid: 2008859
references.citation: J Appl Physiol (1985). 2006 Aug;101(2):531-44
references.pmid: 16614355
references.citation: Endocrine. 1997 Aug;7(1):57-60
references.pmid: 9449033
references.citation: Sports Med. 2008;38(9):781-93
references.pmid: 18712944
references.citation: J Appl Physiol (1985). 1991 May;70(5):1912-6
references.pmid: 1864770
references.citation: Sports Med. 2008;38(7):579-606
references.pmid: 18557660
references.citation: J Appl Physiol (1985). 1992 May;72(5):1780-6
references.pmid: 1601786
references.citation: Clin Endocrinol (Oxf). 1996 Dec;45(6):681-8
references.pmid: 9039333
references.citation: J Biomech. 2008 Nov 14;41(15):3133-8
references.pmid: 18976996
references.citation: J Neurol Sci. 1988 Apr;84(2-3):275-94
references.pmid: 3379447
references.citation: Neuropeptides. 1996 Apr;30(2):159-65
references.pmid: 8771558
references.citation: Am J Physiol. 1997 Oct;273(4):R1557-61
references.pmid: 9362324
references.citation: J Appl Physiol (1985). 1999 Sep;87(3):982-92
references.pmid: 10484567
references.citation: Annu Rev Nutr. 2002;22:309-23
references.pmid: 12055348
references.citation: J Clin Endocrinol Metab. 2004 Apr;89(4):1844-8
references.pmid: 15070954
references.citation: J Appl Physiol (1985). 2005 Jul;99(1):95-102
references.pmid: 15746299
references.citation: Mech Ageing Dev. 2003 Mar;124(3):287-99
references.pmid: 12663126
references.citation: J Gerontol A Biol Sci Med Sci. 1996 Nov;51(6):M270-5
references.pmid: 8914498
references.citation: Am J Physiol. 1989 Mar;256(3 Pt 1):E352-6
references.pmid: 2646944
references.citation: Aging (Milano). 1997 Feb-Apr;9(1-2):106-11
references.pmid: 9177593
references.citation: J Physiol. 2004 Feb 1;554(Pt 3):803-13
references.pmid: 14608013
references.citation: J Appl Physiol (1985). 1988 Mar;64(3):1038-44
references.pmid: 3366726
references.citation: Scand J Med Sci Sports. 2010 Feb;20(1):5-9
references.pmid: 19558380
references.citation: Sports Med. 2000 Nov;30(5):327-46
references.pmid: 11103847
references.citation: Growth Horm IGF Res. 2009 Apr;19(2):146-55
references.pmid: 18812263
references.citation: Appl Physiol Nutr Metab. 2006 Oct;31(5):557-64
references.pmid: 17111010
references.citation: Acta Physiol Scand. 1990 Sep;140(1):41-54
references.pmid: 2275404
references.citation: Regul Pept. 2007 Mar 1;139(1-3):65-71
references.pmid: 17113660
references.citation: Am J Physiol. 1990 Jun;258(6 Pt 1):E990-8
references.pmid: 2360629
references.citation: Arch Phys Med Rehabil. 1998 Jan;79(1):24-30
references.pmid: 9440412
references.citation: Med Sci Sports Exerc. 2002 Jul;34(7):1199-206
references.pmid: 12131263
references.citation: J Physiol Pharmacol. 2006 Nov;57 Suppl 6:55-61
references.pmid: 17228087
references.citation: J Appl Physiol (1985). 2003 Oct;95(4):1717-27
references.pmid: 12970377
references.citation: J Gerontol A Biol Sci Med Sci. 2001 May;56(5):M281-6
references.pmid: 11320107
references.citation: J Appl Physiol (1985). 1997 Aug;83(2):623-30
references.pmid: 9262461
references.citation: Clin Physiol. 1997 Sep;17(5):459-74
references.pmid: 9347195
references.citation: J Appl Physiol (1985). 1999 Jan;86(1):195-201
references.pmid: 9887131
references.citation: Muscle Nerve. 2003 Nov;28(5):601-8
references.pmid: 14571463
references.citation: Biochem Biophys Res Commun. 2004 May 14;317(4):1045-51
references.pmid: 15094374
references.citation: J Gerontol. 1990 Jul;45(4):B125-8
references.pmid: 2365961
references.citation: J Am Coll Nutr. 1995 Dec;14(6):587-94
references.pmid: 8598419
references.citation: J Gerontol A Biol Sci Med Sci. 2000 Dec;55(12):M757-60
references.pmid: 11129399
references.citation: J Gerontol A Biol Sci Med Sci. 2003 Oct;58(10):M918-22
references.pmid: 14570859
references.citation: Sports Med. 2005;35(4):339-61
references.pmid: 15831061
references.citation: Am J Physiol. 1996 May;270(5 Pt 1):E864-72
references.pmid: 8967476
references.citation: Exp Gerontol. 2007 Aug;42(8):733-44
references.pmid: 17624709
references.citation: Chronobiol Int. 2005;22(6):1013-27
references.pmid: 16393705
references.citation: Clin Physiol Funct Imaging. 2004 Mar;24(2):85-90
references.pmid: 15056180
references.citation: FASEB J. 2001 Feb;15(2):475-82
references.pmid: 11156963
references.citation: J Am Geriatr Soc. 1999 Oct;47(10):1208-14
references.pmid: 10522954
references.citation: Clin Endocrinol (Oxf). 2005 Jan;62(1):114-8
references.pmid: 15638879
references.citation: Can J Sport Sci. 1992 Mar;17(1):3-7
references.pmid: 1322766
references.citation: Acta Physiol Scand. 2003 Jan;177(1):69-78
references.pmid: 12492780
references.citation: J Gerontol A Biol Sci Med Sci. 1995 Nov;50 Spec No:11-6
references.pmid: 7493202
references.citation: JAMA. 1990 Jun 13;263(22):3029-34
references.pmid: 2342214
references.citation: Arch Phys Med Rehabil. 2001 Jul;82(7):872-8
references.pmid: 11441371
references.citation: Sports Med. 2006;36(3):215-38
references.pmid: 16526834
references.citation: Acta Physiol Scand. 2001 Jan;171(1):51-62
references.pmid: 11350263
references.citation: Aging Cell. 2004 Aug;3(4):151-60
references.pmid: 15268748
references.citation: Endocr Rev. 1995 Feb;16(1):3-34
references.pmid: 7758431
references.citation: J Am Geriatr Soc. 1995 Oct;43(10):1081-7
references.pmid: 7560695
references.citation: Pituitary. 2007;10(2):129-33
references.pmid: 17487588
references.citation: Muscle Nerve. 2006 Jun;33(6):792-800
references.pmid: 16523507
references.citation: Acta Physiol Scand. 1999 Jan;165(1):51-6
references.pmid: 10072097
references.citation: Clin Physiol. 1985 Apr;5(2):145-54
references.pmid: 3888498
references.citation: Diabetologia. 1985 Jul;28(7):412-9
references.pmid: 3899825
references.citation: Br J Pharmacol. 2008 Jun;154(3):557-68
references.pmid: 18500379
references.citation: J Appl Physiol (1985). 2003 Dec;95(6):2229-34
references.pmid: 12844499
references.citation: J Cardiopulm Rehabil Prev. 2007 Sep-Oct;27(5):298-302
references.pmid: 17885508
references.citation: J Appl Physiol (1985). 2000 Apr;88(4):1321-6
references.pmid: 10749826