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Extending quality of life and attenuating functional decline is paramount in older adults. This study investigates the effects of low-intensity power-training in older women and its effects on functional outcomes.
Resistance training has gained popularity in aging interventions since it is effective in countering the loss of muscle mass and strength with senescence. Traditionally, strength training (ST) protocols for the elderly have involved relatively heavy loads (70-80% of maximum force) with the focus being on increasing strength. There is some evidence of increased function after strength training albeit with inconsistent reports in the literature. More recently, several studies have designed resistance training programs that aim to increase power rather than strength, since findings indicate that measures of power are better predictors of physical function than measures of strength. In other words, improving power may be more beneficial to the elderly who are susceptible to functional limitations, mobility disability, and dependency. Since it is difficult to produce a great deal of power with increasing intensities, and lifting heavy loads may not be relevant to everyday functioning in the elderly, studies have investigated training for improvements in power rather than the traditional improvements in strength.
The effects of power training (PT) versus ST on functional outcomes in older adults have varied, with some studies showing enhanced improvements in function, and others showing no difference in function compared to regular ST or compared to other interventions such as walking. Discrepancies might be the result of the variety of functional tests used, mode of training, variable frequency of sessions per week, differences in study length, and adults of varying functional status. It has been suggested that perhaps the standard 3-sessions-per-week frequency may not be optimal for the elderly. A previous investigation demonstrated that the effects from PT at 40% of the 1-repetition maximum (1RM: the highest amount that can be lifted once) in older adults was comparable to the effects from ST at 80% 1RM with improvements being similar between the two modes despite the lower daily ratings of perceived exertion (RPE) reported with PT (PT: RPE for leg press (12.2) and knee extension (14.6) vs ST: RPE for leg press (15.1) and knee extension (17)). Therefore, an 'easier' exercise training experience did not result in sacrifices in gains of strength and power. In theory, these factors (lighter loads, lower perceived exertions, similar strength and power gains) could affect adherence to exercise during and after a research-related exercise intervention has been completed and thus are important considerations in the design of a training program.
The purpose of this research is to investigate the effects of low-intensity (40% 1RM) PT on functional outcomes in older women.
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| Label | Type | Description | Intervention Names |
|---|---|---|---|
| Once a week | Experimental | Group 1 will be invited to perform resistance training exercise 1 day/week. After a 2-week familiarization phase, participants will engage in power training (40% of 1-repetition maximum) for 12 weeks. Instructions include telling participants to lift the weight concentrically 'as fast as possible', with a lowering phase (eccentric) of 2-3 seconds. Participants will perform 3 x 12-14 repetitions per exercise per session. Primarily lower body equipment will be used, including leg press, knee extension/flexion, hip extension/flexion, and calf-raises. |
|
| Twice a week | Experimental | Group 2 will be invited to perform resistance training exercise 2 days/week. After a 2-week familiarization phase, participants will engage in power training (40% of 1-repetition maximum) for 12 weeks. Instructions include telling participants to lift the weight concentrically 'as fast as possible', with a lowering phase (eccentric) of 2-3 seconds. Participants will perform 3 x 12-14 repetitions per exercise per session. Primarily lower body equipment will be used, including leg press, knee extension/flexion, hip extension/flexion, and calf-raises. |
|
| Thrice a week | Experimental | Group 3 will be invited to perform resistance training exercise 3 days/week. After a 2-week familiarization phase, participants will engage in power training (40% of 1-repetition maximum) for 12 weeks. Instructions include telling participants to lift the weight concentrically 'as fast as possible', with a lowering phase (eccentric) of 2-3 seconds. Participants will perform 3 x 12-14 repetitions per exercise per session. Primarily lower body equipment will be used, including leg press, knee extension/flexion, hip extension/flexion, and calf-raises. |
| Name | Type | Description | Arm Group Labels | Other Names |
|---|---|---|---|---|
| power training | Other | Resistance training machines with CAM devices will be used for training. |
|
| Measure | Description | Time Frame |
|---|---|---|
| Change in Stair-climb power | The time needed to ascend a flight of stairs, converted to power (using body-weight and stair height) | baseline, 6 weeks, 12 weeks |
| Measure | Description | Time Frame |
|---|---|---|
| Change in 400-meter walk test | The time needed to walk 400 meters (back and forth along a 20 meter course) | baseline, 6 weeks, 12 weeks |
| Change in Short Physical Performance Battery | A short test of balance, walking, and chair stand ability |
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Inclusion Criteria:
Exclusion Criteria:
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| Name | Affiliation | Role |
|---|---|---|
| Catherine E Amara, Ph.D | University of Toronto; Faculty of Kinesiology and Physical Education | Study Director |
| Facility | Status | City | State | ZIP | Country | Contacts |
|---|---|---|---|---|---|---|
| Athletic Centre; 55 Harbord Street | Toronto | Ontario | M5S 2W6 | Canada |
| PubMed Identifier | Type | Citation | Retractions |
|---|---|---|---|
| 8190152 | Background | Fiatarone MA, O'Neill EF, Ryan ND, Clements KM, Solares GR, Nelson ME, Roberts SB, Kehayias JJ, Lipsitz LA, Evans WJ. Exercise training and nutritional supplementation for physical frailty in very elderly people. N Engl J Med. 1994 Jun 23;330(25):1769-75. doi: 10.1056/NEJM199406233302501. | |
| 17313273 | Background |
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| ID | Term |
|---|---|
| D055948 | Sarcopenia |
| D018908 | Muscle Weakness |
| ID | Term |
|---|---|
| D009133 | Muscular Atrophy |
| D020879 | Neuromuscular Manifestations |
| D009461 | Neurologic Manifestations |
| D009422 | Nervous System Diseases |
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| ID | Term |
|---|---|
| D055070 | Resistance Training |
| ID | Term |
|---|---|
| D005081 | Exercise Therapy |
| D012046 | Rehabilitation |
| D000359 | Aftercare |
| D003266 | Continuity of Patient Care |
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With 3 groups and a wait-control group, our general design will include 4 (group) x 2 (baseline and post-study) and 4 (group) x 3 (baseline, midpoint, and post-study) analyses. We may also conduct one-way ANOVA analyses as problems with normality in the data are apparent.
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Functional testers are masked to what group the participants are in (control, Exercise Group I, II, or III). All testers are masked during baseline testing.
| wait-control | No Intervention | Participants in this group will serve as controls prior to participating in power training in 1 of the above treatment groups. The control period will last as long as the exercise period, or 3 months. Controls will participate in the same testing time points as the exercisers (baseline, midpoint, and post-intervention). |
|
| baseline, 6 weeks, 12 weeks |
| Change in 30-second chair stand test | The number of chair stands possible in 30 seconds | baseline, 6 weeks, 12 weeks |
| Hartman MJ, Fields DA, Byrne NM, Hunter GR. Resistance training improves metabolic economy during functional tasks in older adults. J Strength Cond Res. 2007 Feb;21(1):91-5. doi: 10.1519/00124278-200702000-00017. |
| 19910811 | Background | Hanson ED, Srivatsan SR, Agrawal S, Menon KS, Delmonico MJ, Wang MQ, Hurley BF. Effects of strength training on physical function: influence of power, strength, and body composition. J Strength Cond Res. 2009 Dec;23(9):2627-37. doi: 10.1519/JSC.0b013e3181b2297b. |
| 22626972 | Background | Pojednic RM, Clark DJ, Patten C, Reid K, Phillips EM, Fielding RA. The specific contributions of force and velocity to muscle power in older adults. Exp Gerontol. 2012 Aug;47(8):608-13. doi: 10.1016/j.exger.2012.05.010. Epub 2012 May 22. |
| 15743291 | Background | Sayers SP, Guralnik JM, Thombs LA, Fielding RA. Effect of leg muscle contraction velocity on functional performance in older men and women. J Am Geriatr Soc. 2005 Mar;53(3):467-71. doi: 10.1111/j.1532-5415.2005.53166.x. |
| 12586856 | Background | Miszko TA, Cress ME, Slade JM, Covey CJ, Agrawal SK, Doerr CE. Effect of strength and power training on physical function in community-dwelling older adults. J Gerontol A Biol Sci Med Sci. 2003 Feb;58(2):171-5. doi: 10.1093/gerona/58.2.m171. |
| 22500229 | Background | Sayers SP, Gibson K. Effects of high-speed power training on muscle performance and braking speed in older adults. J Aging Res. 2012;2012:426278. doi: 10.1155/2012/426278. Epub 2012 Feb 28. |
| 18245765 | Background | Henwood TR, Riek S, Taaffe DR. Strength versus muscle power-specific resistance training in community-dwelling older adults. J Gerontol A Biol Sci Med Sci. 2008 Jan;63(1):83-91. doi: 10.1093/gerona/63.1.83. |
| 22056537 | Background | Drey M, Zech A, Freiberger E, Bertsch T, Uter W, Sieber CC, Pfeifer K, Bauer JM. Effects of strength training versus power training on physical performance in prefrail community-dwelling older adults. Gerontology. 2012;58(3):197-204. doi: 10.1159/000332207. Epub 2011 Nov 3. |
| 11441371 | Background | Earles DR, Judge JO, Gunnarsson OT. Velocity training induces power-specific adaptations in highly functioning older adults. Arch Phys Med Rehabil. 2001 Jul;82(7):872-8. doi: 10.1053/apmr.2001.23838. |
| 12586847 | Background | Bamman MM, Hill VJ, Adams GR, Haddad F, Wetzstein CJ, Gower BA, Ahmed A, Hunter GR. Gender differences in resistance-training-induced myofiber hypertrophy among older adults. J Gerontol A Biol Sci Med Sci. 2003 Feb;58(2):108-16. doi: 10.1093/gerona/58.2.b108. |
| 11581563 | Background | Hunter GR, Wetzstein CJ, McLafferty CL Jr, Zuckerman PA, Landers KA, Bamman MM. High-resistance versus variable-resistance training in older adults. Med Sci Sports Exerc. 2001 Oct;33(10):1759-64. doi: 10.1097/00005768-200110000-00022. |
| 37335760 | Derived | Katsoulis K, Amara CE. The Effects of Power Training Frequency on Muscle Power and Functional Performance in Older Women: A Randomized Controlled Trial. J Strength Cond Res. 2023 Nov 1;37(11):2289-2297. doi: 10.1519/JSC.0000000000004527. Epub 2023 Jun 19. |
| D001284 | Atrophy |
| D020763 | Pathological Conditions, Anatomical |
| D013568 | Pathological Conditions, Signs and Symptoms |
| D012816 | Signs and Symptoms |
| D009135 | Muscular Diseases |
| D009140 | Musculoskeletal Diseases |
| D010335 | Pathologic Processes |
| D005791 |
| Patient Care |
| D013812 | Therapeutics |
| D026741 | Physical Therapy Modalities |
| D064797 | Physical Conditioning, Human |
| D015444 | Exercise |
| D009043 | Motor Activity |
| D009068 | Movement |
| D009142 | Musculoskeletal Physiological Phenomena |
| D055687 | Musculoskeletal and Neural Physiological Phenomena |