This systematic review examines the effectiveness of current exercise interventions for the management of frailty. Eight electronic databases were searched for randomized controlled trials that identified their participants as “frail” either in the title, abstract, and/or text and included exercise as an independent component of the intervention. Three of the 47 included studies utilized a validated definition of frailty to categorize participants. Emerging evidence suggests that exercise has a positive impact on some physical determinants and on all functional ability outcomes reported in this systematic review. Exercise programs that optimize the health of frail older adults seem to be different from those recommended for healthy older adults. There was a paucity of evidence to characterize the most beneficial exercise program for this population. However, multicomponent training interventions, of long duration (≥5 months), performed three times per week, for 30–45 minutes per session, generally had superior outcomes than other exercise programs. In conclusion, structured exercise training seems to have a positive impact on frail older adults and may be used for the management of frailty. 1. Introduction Frailty is an increasingly recognized geriatric syndrome that has a tremendous impact on the older individual, their family, and society as a whole. The terms “frail” and “frailty” are often used in the literature without clear definition or criteria [1]. Frailty is a complex concept and the precise definition remains to be elucidated. However, there is broad support for the understanding that frailty is a state of vulnerability, caused by multisystem reduction, ranging in severity from mild to severe, that places the individual at increased risk of adverse health outcomes [2, 3]. The components of frailty are a mix of physiological, psychological, social, and environmental factors (e.g., sarcopenia, functional impairment, cognitive impairment, and depression). There is also a compelling need for effective interventions that manage frailty symptoms and as such, exercise may be the best medicine for this population. Even though numerous operational (clinical) definitions of frailty were proposed to help develop screening criteria, there is not yet a standardized and valid method of clinically screening for frailty [4]. The most commonly used definitions of frailty are the frailty phenotype [5], the frailty index [6], the classification of frailty and vigorousness [7], and the Edmonton frail scale [8]. Fried et al. [5] proposed five indicators of
References
[1]
M. Markle-Reid and G. Browne, “Conceptualizations of frailty in relation to older adults,” Journal of Advanced Nursing, vol. 44, no. 1, pp. 58–68, 2003.
[2]
D. B. Hogan, C. MacKnight, and H. Bergman, “Models, definitions, and criteria of frailty,” Aging Clinical and Experimental Research, vol. 15, no. 3, pp. 1–29, 2003.
[3]
L. Ferrucci, J. M. Guralnik, S. Studenski, L. P. Fried, G. B. Cutler Jr., and J. D. Walston, “Designing randomized, controlled trials aimed at preventing or delaying functional decline and disability in frail, older persons: a consensus report,” Journal of the American Geriatrics Society, vol. 52, no. 4, pp. 625–634, 2004.
[4]
O. Theou and M. Kloseck, “Tools to identify community-dwelling older adults in different stages of frailty,” Physical and Occupational Therapy in Geriatrics, vol. 26, no. 3, pp. 1–21, 2008.
[5]
L. P. Fried, C. M. Tangen, J. Walston et al., “Frailty in older adults: evidence for a phenotype,” Journals of Gerontology A, vol. 56, no. 3, pp. M146–M156, 2001.
[6]
K. Rockwood and A. Mitnitski, “Frailty in relation to the accumulation of deficits,” Journals of Gerontology A, vol. 62, no. 7, pp. 722–727, 2007.
[7]
M. Speechley and M. Tinetti, “Falls and injuries in frail and vigorous community elderly persons,” Journal of the American Geriatrics Society, vol. 39, no. 1, pp. 46–52, 1991.
[8]
D. B. Rolfson, S. R. Majumdar, R. T. Tsuyuki, A. Tahir, and K. Rockwood, “Validity and reliability of the edmonton frail scale,” Age and Ageing, vol. 35, no. 5, pp. 526–529, 2006.
[9]
D. H. Paterson, G. R. Jones, and C. L. Rice, “Aging and physical activity data on which to base recommendations for exercise in older adults,” Applied Physiology, Nutrition, and Metabolism, vol. 32, no. 2F, supplement, pp. S75–S171, 2007.
[10]
T. M. Gill, E. A. Gahbauer, H. G. Allore, and L. Han, “Transitions between frailty states among community-living older persons,” Archives of Internal Medicine, vol. 166, no. 4, pp. 418–423, 2006.
[11]
“American College of Sports Medicine position stand. Exercise and physical activity for older adults,” Medicine & Science in Sports & Exercise, vol. 30, no. 6, pp. 992–1008, 1998.
[12]
“American College of Sports Medicine position stand. Exercise and physical activity for older adults,” Medicine & Science in Sports & Exercise, vol. 41, no. 7, pp. 1510–1530, 2009.
[13]
R. Orr, J. Raymond, and M. F. Singh, “Efficacy of progressive resistance training on balance performance in older adults: a systematic review of randomized controlled trials,” Sports Medicine, vol. 38, no. 4, pp. 317–343, 2008.
[14]
J. G. Z. van Uffelen, A. Chin, M. J. Paw, M. Hopman-Rock, and W. van Mechelen, “The effects of exercise on cognition in older adults with and without cognitive decline: a systematic review,” Clinical Journal of Sport Medicine, vol. 18, no. 6, pp. 486–500, 2008.
[15]
P. G. Shekelle, M. Maglione, W. Mojica, et al., Exercise Programs for Older Adults: A Systematic Review and Meta-Analysis, RAND Corporation Reprint Series, Centers for Medicare and Medicaid Services, Baltimore, Md, USA, 2003.
[16]
A. Chin, M. J. Paw, J. G. Z. van Uffelen, I. Riphagen, and W. van Mechelen, “The functional effects of physical exercise training in frail older people: a systematic review,” Sports Medicine, vol. 38, no. 9, pp. 781–793, 2008.
[17]
R. Daniels, E. van Rossum, L. de Witte, G. I. Kempen, and W. van den Heuvel, “Interventions to prevent disability in frail community-dwelling elderly: a systematic review,” BMC Health Services Research, vol. 8, article 278, 2008.
[18]
F. Landi, A. M. Abbatecola, M. Provinciali, et al., “Moving against frailty: does physical activity matter?” Biogerontology, vol. 11, no. 5, pp. 537–545, 2010.
[19]
C. J. Casperson, K. E. Powell, and G. M. Christensen, “Physical activity, exercise, and physical fitness: definitions and distinctions for health-related research,” Public Health Reports, vol. 100, no. 2, pp. 126–131, 1985.
A. R. Jadad, R. A. Moore, D. Carroll et al., “Assessing the quality of reports of randomized clinical trials: is blinding necessary?” Controlled Clinical Trials, vol. 17, no. 1, pp. 1–12, 1996.
[22]
N. de Jong, “Sensible aging: using nutrient-dense foods and physical exercise with the frail elderly,” Nutrition Today, vol. 36, no. 4, pp. 202–207, 2001.
[23]
A. Chin, M. J. Paw, N. de Jong, E. G. Schouten, G. J. Hiddink, and F. J. Kok, “Physical exercise and/or enriched foods for functional improvement in frail, independently living elderly: a randomized controlled trial,” Archives of Physical Medicine and Rehabilitation, vol. 82, no. 6, pp. 811–817, 2001.
[24]
N. de Jong, A. Chin, M. J. Paw, C. de Graaf, and W. A. van Staveren, “Effect of dietary supplements and physical exercise on sensory perception, appetite, dietary intake and body weight in frail elderly subjects,” British Journal of Nutrition, vol. 83, no. 6, pp. 605–613, 2000.
[25]
N. de Jong, A. Chin, M. J. Paw, et al., “Functional biochemical and nutrient indices in frail elderly people are partly affected by dietary supplements but not by exercise,” Journal of Nutrition, vol. 129, no. 11, pp. 2028–2036, 1999.
[26]
N. de Jong, A. Chin, M. J. Paw, L. C. P. G. M. de Groot, G. J. Hiddink, and W. A. van Staveren, “Dietary supplements and physical exercise affecting bone and body composition in frail elderly persons,” American Journal of Public Health, vol. 90, no. 6, pp. 947–954, 2000.
[27]
A. Chin, M. J. Paw, N. de Jong, E. G. Schouten, W. A. van Staveren, and F. J. Kok, “Physical exercise or micronutrient supplementation for the wellbeing of the frail elderly? A randomised controlled trial,” British Journal of Sports Medicine, vol. 36, no. 2, pp. 126–131, 2002.
[28]
N. de Jong, A. Chin, M. J. Paw, et al., “Nutrient-dense foods and exercise in frail elderly: effects on B vitamins, homocysteine, methylmalonic acid, and neuropsychological functioning,” American Journal of Clinical Nutrition, vol. 73, no. 2, pp. 338–346, 2001.
[29]
A. Chin, M. J. Paw, N. de Jong, et al., “Immunity in frail elderly: a randomized controlled trial of exercise and enriched foods,” Medicine and Science in Sports and Exercise, vol. 32, no. 12, pp. 2005–2011, 2000.
[30]
E. F. Binder, K. B. Schechtman, A. A. Ehsani et al., “Effects of exercise training on frailty in community-dwelling older adults: results of a randomized, controlled trial,” Journal of the American Geriatrics Society, vol. 50, no. 12, pp. 1921–1928, 2002.
[31]
E. F. Binder, K. E. Yarasheski, K. Steger-May et al., “Effects of progressive resistance training on body composition in frail older adults: results of a randomized, controlled trial,” Journals of Gerontology A, vol. 60, no. 11, pp. 1425–1431, 2005.
[32]
A. A. Ehsani, R. J. Spina, L. R. Peterson et al., “Attenuation of cardiovascular adaptations to exercise in frail octogenarians,” Journal of Applied Physiology, vol. 95, no. 5, pp. 1781–1788, 2003.
[33]
D. T. Villareal, K. Steger-May, K. B. Schechtman et al., “Effects of exercise training on bone mineral density in frail order women and men: a radomised controlled trial,” Age and Ageing, vol. 33, no. 3, pp. 309–312, 2004.
[34]
T. M. Gill, D. I. Baker, M. Gottschalk, P. N. Peduzzi, H. Allore, and A. Byers, “A program to prevent functional decline in physically frail, elderly persons who live at home,” The New England Journal of Medicine, vol. 347, no. 14, pp. 1068–1074, 2002.
[35]
P. Peduzzi, Z. Guo, R. A. Marottoli, T. M. Gill, K. Araujo, and H. G. Allore, “Improved self-confidence was a mechanism of action in two geriatric trials evaluating physical interventions,” Journal of Clinical Epidemiology, vol. 60, no. 1, pp. 94–102, 2007.
[36]
T. M. Gill, D. I. Baker, M. Gottschalk et al., “A prehabilitation program for physically frail community-living older persons,” Archives of Physical Medicine and Rehabilitation, vol. 84, no. 3, pp. 394–404, 2003.
[37]
T. M. Gill, D. I. Baker, M. Gottschalk, P. N. Peduzzi, H. Allore, and P. H. Van Ness, “A prehabilitation program for the prevention of functional decline: effect on higher-level physical function,” Archives of Physical Medicine and Rehabilitation, vol. 85, no. 7, pp. 1043–1049, 2004.
[38]
K. E. Yarasheski, J. Pak-Loduca, D. L. Hasten, K. A. Obert, M. B. Brown, and D. R. Sinacore, “Resistance exercise training increases mixed muscle protein synthesis rate in frail women and men ≥ 76 yr old,” American Journal of Physiology, vol. 277, no. 1, pp. E118–E125, 1999.
[39]
J. N. Schulte and K. E. Yarasheski, “Effects of resistance training on the rate of muscle protein synthesis in frail elderly people,” International Journal of Sport Nutrition and Exercise Metabolism, vol. 11, pp. S111–S118, 2001.
[40]
J. S. Greiwe, C. Bo, D. C. Rubin, K. E. Yarasheski, and C. F. Semenkovich, “Resistance exercise decreases skeletal muscle tumor necrosis factor α in frail elderly humans,” FASEB Journal, vol. 15, no. 2, pp. 475–482, 2001.
[41]
C. H. Worm, E. Vad, L. Puggaard, H. St？vring, J. Lauritsen, and J. Kragstrup, “Effects of a multicomponent exercise program on functional ability in community-dwelling, frail older adults,” Journal of Aging and Physical Activity, vol. 9, no. 4, pp. 414–424, 2001.
[42]
H. Frederiksen, L. Bathum, C. Worm, K. Christensen, and L. Puggaard, “ACE genotype and physical training effects: a randomized study among elderly Danes,” Aging Clinical and Experimental Research, vol. 15, no. 4, pp. 284–291, 2003.
[43]
H. C. Boshuizen, L. Stemmerik, M. H. Westhoff, and M. Hopman-Rock, “The effects of physical therapists' guidance on improvement in a strength-training program for the frail elderly,” Journal of Aging and Physical Activity, vol. 13, no. 1, pp. 5–22, 2005.
[44]
M. H. Westhoff, L. Stemmerik, and H. C. Boshuizen, “Effects of a low-intensity strength-training program on knee-extensor strength and functional ability of frail older people,” Journal of Aging and Physical Activity, vol. 8, no. 4, pp. 325–342, 2000.
[45]
E. Rosendahl, N. Lindel？f, H. Littbrand et al., “High-intensity functional exercise program and protein-enriched energy supplement for older persons dependent in activities of daily living: a randomised controlled trial,” Australian Journal of Physiotherapy, vol. 52, no. 2, pp. 105–113, 2006.
[46]
E. Rosendahl, Y. Gustafson, E. Nordin, L. Lundin-Olsson, and L. Nyberg, “A randomized controlled trial of fall prevention by a high-intensity functional exercise program for older people living in residential care facilities,” Aging Clinical and Experimental Research, vol. 20, no. 1, pp. 67–75, 2008.
[47]
S. E. Sihvonen, S. Sipil？, and P. A. Era, “Changes in postural balance in frail elderly women during a 4-week visual feedback training: a randomized controlled trial,” Gerontology, vol. 50, no. 2, pp. 87–95, 2004.
[48]
S. Sihvonen, S. Sipil？, S. Taskinen, and P. Era, “Fall incidence in frail older women after individualized visual feedback-based balance training,” Gerontology, vol. 50, no. 6, pp. 411–416, 2004.
[49]
M. A. Fiatarone, E. F. O'Neill, N. D. Ryan et al., “Exercise training and nutritional supplementation for physical frailty in very elderly people,” The New England Journal of Medicine, vol. 330, no. 25, pp. 1769–1775, 1994.
[50]
M. A. Fiatarone Singh, W. Ding, T. J. Manfredi et al., “Insulin-like growth factor I in skeletal muscle after weight-lifting exercise in frail elders,” American Journal of Physiology, vol. 277, no. 1, pp. E135–E143, 1999.
[51]
M. L. Urso, M. A. Fiatarone Singh, W. Ding, W. J. Evans, A. C. Cosmas, and T. G. Manfredi, “Exercise training effects on skeletal muscle plasticity and IGF-1 receptors in frail elders,” Age, vol. 27, no. 2, pp. 117–125, 2005.
[52]
S. L. Wolf, R. W. Sattin, M. Kutner, M. O'Grady, A. I. Greenspan, and R. J. Gregor, “Intense Tai Chi exercise training and fall occurrences in older, transitionally frail adults: a randomized, controlled trial,” Journal of the American Geriatrics Society, vol. 51, no. 12, pp. 1693–1701, 2003.
[53]
R. W. Sattin, K. A. Easley, S. L. Wolf, Y. Chen, and M. H. Kutner, “Reduction in fear of falling through intense tai chi exercise training in older, transitionally frail adults,” Journal of the American Geriatrics Society, vol. 53, no. 7, pp. 1168–1178, 2005.
[54]
S. L. Wolf, M. O'Grady, K. A. Easley, Y. Guo, R. W. Kressig, and M. Kutner, “The influence of intense Tai Chi training on physical performance and hemodynamic outcomes in transitionally frail, older adults,” Journals of Gerontology A, vol. 61, no. 2, pp. 184–189, 2006.
[55]
C. J. Hass, R. J. Gregor, D. E. Waddell et al., “The influence of Tai Chi training on the center of pressure trajectory during gait initiation in older adults,” Archives of Physical Medicine and Rehabilitation, vol. 85, no. 10, pp. 1593–1598, 2004.
[56]
A. I. Greenspan, S. L. Wolf, M. E. Kelley, and M. O'Grady, “Tai Chi and perceived health status in older adults who are transitionally frail: a randomized controlled trial,” Physical Therapy, vol. 87, no. 5, pp. 525–535, 2007.
[57]
L. Timonen, T. Rantanen, E. M？kinen, T. E. Timonen, T. T？rm？kangas, and R. Sulkava, “Cost analysis of an exercise program for older women with respect to social welfare and healthcare costs: a pilot study,” Scandinavian Journal of Medicine and Science in Sports, vol. 18, no. 6, pp. 783–789, 2008.
[58]
L. Timonen, T. Rantanen, O. P. Ryyn？nen, S. Taimela, T. E. Timonen, and R. Sulkava, “A randomized controlled trial of rehabilitation after hospitalization in frail older women: effects on strength, balance and mobility,” Scandinavian Journal of Medicine and Science in Sports, vol. 12, no. 3, pp. 186–192, 2002.
[59]
L. Timonen, T. Rantanen, T. E. Timonen, and R. Sulkava, “Effects of a group-based exercise program on the mood state of frail older women after discharge from hospital,” International Journal of Geriatric Psychiatry, vol. 17, no. 12, pp. 1106–1111, 2002.
[60]
J. A. Schmidt, C. Gruman, M. B. King, and L. I. Wolfson, “Attrition in an exercise intervention: a comparison of early and later dropouts,” Journal of the American Geriatrics Society, vol. 48, no. 8, pp. 952–960, 2000.
[61]
H. G. Rincón, G. F. Solomon, D. Benton, and L. Z. Rubenstein, “Exercise in frail elderly men decreases natural killer cell activity,” Aging Clinical and Experimental Research, vol. 8, no. 2, pp. 109–112, 1996.
[62]
J. V. Hennessey, J. A. Chromiak, S. Della Ventura et al., “Growth hormone administration and exercise effects on muscle fiber type and diameter in moderately frail older people,” Journal of the American Geriatrics Society, vol. 49, no. 7, pp. 852–858, 2001.
[63]
J. F. Bean, S. Herman, D. K. Kiely et al., “Increased velocity exercise specific to task (InVEST) training: a pilot study exploring effects on leg power, balance, and mobility in community-dwelling older women,” Journal of the American Geriatrics Society, vol. 52, no. 5, pp. 799–804, 2004.
[64]
M. Brown, D. R. Sinacore, A. A. Ehsani, E. F. Binder, J. O. Holloszy, and W. M. Kohrt, “Low-intensity exercise as a modifier of physical frailty in older adults,” Archives of Physical Medicine and Rehabilitation, vol. 81, no. 7, pp. 960–965, 2000.
[65]
J. M. Chandler, P. W. Duncan, G. Kochersberger, and S. Studenski, “Is lower extremity strength gain associated with improvement in physical performance and disability in frail, community-dwelling elders?” Archives of Physical Medicine and Rehabilitation, vol. 79, no. 1, pp. 24–30, 1998.
[66]
W. J. Rejeski, A. C. King, J. A. Katula et al., “Physical activity in prefrail older adults: confidence and satisfaction related to physical function,” Journals of Gerontology B, vol. 63, no. 1, pp. P19–P26, 2008.
[67]
N. B. Alexander, A. T. Galecki, M. L. Grenier et al., “Task-specific resistance training to improve the ability of activities of daily living-impaired older adults to rise from a bed and from a chair,” Journal of the American Geriatrics Society, vol. 49, no. 11, pp. 1418–1427, 2001.
[68]
J. F. Schnelle, P. G. MacRae, K. Giacobassi, H. S. H. MacRae, S. F. Simmons, and J. G. Ouslander, “Exercise with physically restrained nursing home residents: maximizing benefits of restraint reduction,” Journal of the American Geriatrics Society, vol. 44, no. 5, pp. 507–512, 1996.
[69]
C. D. Mulrow, M. B. Gerety, D. Kanten et al., “A randomized trial of physical rehabilitation for very frail nursing home residents,” Journal of the American Medical Association, vol. 271, no. 7, pp. 519–524, 1994.
[70]
Z. F. Kapasi, J. G. Ouslander, J. F. Schnelle, M. Kutner, and J. L. Fahey, “Effects of an exercise intervention on immunologic parameters in frail elderly nursing home residents,” Journals of Gerontology A, vol. 58, no. 7, pp. 636–643, 2003.
[71]
E. E. Baum, D. Jarjoura, A. E. Polen, D. Faur, and G. Rutecki, “Effectiveness of a group exercise program in a long-term care facility: a rondomized pilot trial,” Journal of the American Medical Directors Association, vol. 4, no. 2, pp. 74–80, 2003.
[72]
D. H. Sullivan, P. K. Roberson, E. S. Smith, J. A. Price, and M. M. Bopp, “Effects of muscle strength training and megestrol acetate on strength, muscle mass, and function in frail older people,” Journal of the American Geriatrics Society, vol. 55, no. 1, pp. 20–28, 2007.
[73]
D. H. Sullivan, P. K. Roberson, L. E. Johnson et al., “Effects of muscle strength training and testosterone in frail elderly males,” Medicine and Science in Sports and Exercise, vol. 37, no. 10, pp. 1664–1672, 2005.
[74]
E. Rydwik, E. Lammes, K. Fr？ndin, and G. Akner, “Effects of a physical and nutritional intervention program for frail elderly people over age 75. A randomized controlled pilot treatment trial,” Aging Clinical and Experimental Research, vol. 20, no. 2, pp. 159–170, 2008.
[75]
J. L. Helbostad, O. Sletvold, and R. Moe-Nilssen, “Home training with and without additional group training in physically frail old people living at home: effect on health-related quality of life and ambulation,” Clinical Rehabilitation, vol. 18, no. 5, pp. 498–508, 2004.
[76]
K. Hauer, B. Rost, K. Rütschle et al., “Exercise training for rehabilitation and secondary prevention of falls in geriatric patients with a history of injurious falls,” Journal of the American Geriatrics Society, vol. 49, no. 1, pp. 10–20, 2001.
[77]
S. Vestergaard, C. Kronborg, and L. Puggaard, “Home-based video exercise intervention for community-dwelling frail older women: a randomized controlled trial,” Aging Clinical and Experimental Research, vol. 20, no. 5, pp. 479–486, 2008.
[78]
M. Bonnefoy, C. Cornu, S. Normand et al., “The effects of exercise and protein-energy supplements on body composition and muscle function in frail elderly individuals: a long-term controlled randomised study,” British Journal of Nutrition, vol. 89, no. 5, pp. 731–738, 2003.
[79]
M. E. T. McMurdo and L. Rennie, “A controlled trial of exercise by residents of old people's homes,” Age and Ageing, vol. 22, no. 1, pp. 11–15, 1993.
[80]
M. J. Faber, R. J. Bosscher, A. Chin, M. J. Paw, and P. C. van Wieringen, “Effects of exercise programs on falls and mobility in frail and pre-frail older adults: a multicenter randomized controlled trial,” Archives of Physical Medicine and Rehabilitation, vol. 87, no. 7, pp. 885–896, 2006.
[81]
F. Landi, A. Russo, and R. Bernabei, “Physical activity and behavior in the elderly: a pilot study,” Archives of Gerontology and Geriatrics. Supplement, no. 9, pp. 235–241, 2004.
[82]
O. Seynnes, M. A. F. Singh, O. Hue, P. Pras, P. Legros, and P. L. Bernard, “Physiological and functional responses to low-moderate versus high-intensity progressive resistance training in frail elders,” Journals of Gerontology A, vol. 59, no. 5, pp. 503–509, 2004.
[83]
H. Bruunsgaard, E. Bjerregaard, M. Schroll, and B. K. Pedersen, “Muscle strength after resistance training is inversely correlated with baseline levels of soluble tumor necrosis factor receptors in the oldest old,” Journal of the American Geriatrics Society, vol. 52, no. 2, pp. 237–241, 2004.
[84]
I. Bautmans, E. Van Hees, J. C. Lemper, and T. Mets, “The feasibility of whole body vibration in institutionalised elderly persons and its influence on muscle performance, balance and mobility: a randomised controlled trial,” BMC Geriatrics, vol. 5, article 17, p. 8, 2005.
[85]
C. Blanc-Bisson, A. Dechamps, G. Gouspillou, P. Dehail, and I. Bourdel-Marchasson, “A randomized controlled trial on early physiotherapy intervention versus usual care in acute car unit for elderly: potential benefits in light of dietary intakes,” Journal of Nutrition, Health and Aging, vol. 12, no. 6, pp. 395–399, 2008.
[86]
Y. Mitani, K. Doi, T. Yano et al., “Effect of exercise using a horse-riding simulator on physical ability of frail seniors,” Journal of Physical Therapy Science, vol. 20, no. 3, pp. 177–183, 2008.
[87]
H. Shimada, S. Obuchi, T. Furuna, and T. Suzuki, “New intervention program for preventing falls among frail elderly people: the effects of perturbed walking exercise using a bilateral separated treadmill,” American Journal of Physical Medicine and Rehabilitation, vol. 83, no. 7, pp. 493–499, 2004.
[88]
H. Shimada, Y. Uchiyama, and S. Kakurai, “Specific effects of balance and gait exercises on physical function among the frail elderly,” Clinical Rehabilitation, vol. 17, no. 5, pp. 472–479, 2003.
[89]
D. Sato, K. Kaneda, H. Wakabayashi, and T. Nomura, “The water exercise improves health-related quality of life of frail elderly people at day service facility,” Quality of Life Research, vol. 16, no. 10, pp. 1577–1585, 2007.
[90]
M. Makita, H. Nakadaira, and M. Yamamoto, “Randomized controlled trial to evaluate effectiveness of exercise therapy (Takizawa Program) for frail elderly,” Environmental Health and Preventive Medicine, vol. 11, no. 5, pp. 221–227, 2006.
[91]
S. R. Lord, S. Castell, J. Corcoran et al., “The effect of group exercise on physical functioning and falls in frail older people living in retirement villages: a randomized, controlled trial,” Journal of the American Geriatrics Society, vol. 51, no. 12, pp. 1685–1692, 2003.
[92]
N. K. Latham, C. S. Anderson, A. Lee, D. A. Bennett, A. Moseley, and I. D. Cameron, “A randomized, controlled trial of quadriceps resistance exercise and vitamin D in frail older people: the frailty interventions trial in elderly subjects (FITNESS),” Journal of the American Geriatrics Society, vol. 51, no. 3, pp. 291–299, 2003.
[93]
C. M. O'Hagan, D. M. Smith, and K. L. Pileggi, “Exercise classes in rest homes: effect on physical function,” The New Zealand Medical Journal, vol. 107, no. 971, pp. 39–40, 1994.
[94]
K. V. Hruda, A. L. Hicks, and N. McCartney, “Training for muscle power in older adults: effects on functional abilities,” Canadian Journal of Applied Physiology, vol. 28, no. 2, pp. 178–189, 2003.
[95]
D. A. Lazowski, N. A. Ecclestone, A. M. Myers et al., “A randomized outcome evaluation of group exercise programs in long-term care institutions,” Journals of Gerontology A, vol. 54, no. 12, pp. M621–M628, 1999.
[96]
L. Timonen, T. Rantanen, E. M？kinen, T. E. Timonen, T. T？rm？kangas, and R. Sulkava, “Effects of group-based exercise program on functional abilities in frail older women after hospital discharge,” Aging Clinical and Experimental Research, vol. 18, no. 1, pp. 50–56, 2006.
[97]
C. L. Rice and D. A. Cunningham, “Aging of the neuromuscular system: influences of gender and physical activity,” in Gender, Physical Activity, and Aging, R. J. Shephard, Ed., pp. 121–150, CRC Press LLC, Boca Raton, Fla, USA, 2002.
