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Effects of Strength Training on Muscle Properties, Physical Function, and Physical Activity among Frail Older People: A Pilot Study

Effects of Strength Training on Muscle Properties, Physical Function, and Physical Activity among... Hindawi Journal of Aging Research Volume 2018, Article ID 8916274, 11 pages https://doi.org/10.1155/2018/8916274 Clinical Study Effects of Strength Training on Muscle Properties, Physical Function, and Physical Activity among Frail Older People: A Pilot Study Atle Hole Saeterbakken , Hilde Bremseth Ba˚rdstu, Anine Brudeseth, and Vidar Andersen Faculty of Teacher Education, Culture and Sport, Western Norway University of Applied Sciences, Bergen, Norway Correspondence should be addressed to Atle Hole Saeterbakken; atle.saeterbakken@hvl.no Received 7 August 2017; Revised 2 January 2018; Accepted 30 January 2018; Published 3 June 2018 Academic Editor: Jean-Francois Grosset Copyright © 2018 Atle Hole Saeterbakken et al. *is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. *e aim of this study was to determine the effects of a 10-week strength training intervention on isometric strength, rate of force development (RFD), physical function (stair climbing, rising from a chair, and preferred and maximal walking speed), and physical activity among frail elderly people receiving home-care services. *irty participants were randomly assigned (by sex) to a control group (CON) or a strength training group (ST) performing a supervised training programme using elastic bands, box- lifting, and body weight exercises twice per week. Twenty-three participants were selected to complete the study (age 84.9± 6.1 years). For the ST, only improvement in muscle properties was the peak RFD in leg extension (p � 0.04). No significant differences were observed in muscle properties for the control group (CON) (p � 0.16–1.00) or between groups (p � 0.39–1.00). *ere were no changes within and between the groups in physical function (p � 0.12–0.19) or physical activity levels (p � 0.06–0.73). *e results of this pilot study did not demonstrate greater improvements in muscle properties and physical function and improved physical activity after attending a home-based resistance program compared to physical activity advise; however, larger population studies should examine these findings. *is trial is registered with ISRCTN10967873. lack of confidence, or inability to travel to another place. 1. Introduction Further, very few nurse-care centres have well equipped With increasing age, human skeletal muscle undergoes both strength training facilities. Recently, the interest in low-cost structural and functional changes, with a reduction in home-based intervention studies examining the older adults muscle mass and muscle strength [1, 2]. In addition, ageing has grown in popularity [11, 12]. A home-based exercise atrophy is associated with a notable decrease in maximum programme may contribute to increased participations, muscle strength, power, and rate of force development especially among frail older adults who might not have the (RFD) [3, 4]. Reduced muscle mass and muscle strength is opportunity to use gym or fitness facilities [13]. However, the associated with loss of function during typical daily living isolated effects of home-based strength training programs activities such as rising from a chair, stair climbing, and in are not conclusive and have not examined frail older adults postural balance [5]. [11, 14–17]. *erefore, pilot studies with frail older adults Strength training has improved muscle strength, muscle examining training programs (i.e., equipment, volume, mass, and physical function among older adults [6–10]. frequency, intensity, and ability to participate) need to be Traditional strength training studies with elderly people are conducted before starting large-scale studies. conducted in fitness centres with multiple training machines However, typical equipment used in home-based in- [6–10]. However, fitness centres may exclude frail older terventions studies is elastic bands, body weight exercises, adults to participate due to their functional level, discomfort, and other undersized training devices [13], and the 2 Journal of Aging Research equipment is cheap, portable, and saves space compared to informed all elderly people meeting the inclusion criteria (45 a training centre. Intervention studies for the older adults potential participants) to participate in this pilot study. 2/3 using this training equipment have found improvements in of them volunteered, and 30 community-dwelling older muscle strength [16, 17]. However, the transferability of the adults (6 male and 24 female) were recruited. *e partici- improved strength to physical function (i.e., rising from pants were stratified randomly by sex. *e name of each a chair, stair climbing, and postural balance) is not clear. participant was written on a patch and divided into two While traditional and explosive strength training improved heaps—one for each sex. *e patches were thoroughly mixed RFD by 12–50% among 60–89-year-old participants before drawing first the male and then the female to either [18–20], none of the studies examining home-based pro- a strength-training group (ST) (n � 16) or a control group grams have trained explosive strength or included mea- (CON) (n � 14). *e first, third, fifth, and more patches surement of RFD. from each heaps were assigned to the ST group and It is well documented that physical activity (PA) can remaining to the CON group. Seven participants dropped reduce the risks of chronic diseases and contribute to the out during the intervention (five from the ST and two from the CON) with reason not related to the study. Twenty-three enhancement of physical function and maintenance of in- dependence for older adults [21–23]. Overall, the PA level participants (6 male and 17 female) aged 71–97 years decreases with ageing, and only 12% of the 80–85-year-old completed the study (Figure 1). Due to the nature of the age group fulfilled the current PA recommendation of 30 intervention, neither participants nor staff were blinded to minutes of moderate daily activity [24, 25]. However, there is the group allocation or the outcome assessors. Anthropo- a lack of knowledge about the effects of low-cost home-based metric measurements for the two groups are shown in strength training and PA levels among frail older adults. Table 1. Further, the effects of home-based strength training pro- To participate in the study, the following inclusion criteria grams among community-dwelling older adults receiving had to be fulfilled: (1)>70 years of age living at home and (2) health-care services have not been properly examined as in need of home care due to functional disabilities and/or a rehabilitation strategy to prevent the age-related changes in medication. *e exclusion criteria were older adults di- agnosed with chronic mental disorders, for example, Alz- muscle properties and physical function. With a rapid in- creasing numbers of older adults in the next centuries, low- heimer’s disease or injuries and/or diagnoses not justifiable to cost and home-based rehabilitation programs need to be execute testing or training. Explanation of the purpose, examined to decrease the factors associated with needy el- procedures, potential risks, and benefits of the study was given derly being able to live independent and self-reliant of orally and in writing to all participants. A written consent was health-care services. *erefore, the aim of this study was to provided prior to testing. *e study was approved by the local conduct a pilot study to determine the possible harms or ethics committee (REK sør-øst B, 2014/1147). benefits of a home-based strength training programme on physical function tests and level of physical activity in ad- 2.3. Measures dition to muscle strength and RFD among frail old adults. Accordingly, we hypothesized that a 10-week intervention 2.3.1. Maximal Strength and Rate of Force Development could be beneficial for frail older adults by improving muscle (RFD). To test the maximal isometric force output in leg strength, peak RFD, and physical function, but not the PA extension and elbow flexion, a nonelectric sling (ROPES A/S, due to the short intervention period. Asgardstrand, Norway) was placed around the dominant ankle or hand and attached to a force cell (Ergotest A/S, Porsgrunn, Norway). *e knee and elbow angles were 2. Materials and Methods measured for each participant with a paragraph protractor. 2.1. Study Design. *e pilot study was parallel group design ° Both tests were performed with a 90 angle flexion in the where 30 community-dwelling older adults receiving health- knee or elbow joint. Performing the leg extension test, the care services were randomly assigned to either a strength- ° participants were seated with a hip angle of 90 which had to training group (ST) or a control group (CON). *e ST group be maintained during testing [15]. *e participants’ domi- performed a progressive strength-training programme twice nant hand was used to holda semisupinated grip [26], and a week with 10–12 repetitions for 10 weeks. *e CON was the elbow was held closed to the body. Each participant had instructed and encouraged to continue their normal activ- three attempts with a contraction duration of five seconds ities during the intervention. Pre- and postintervention, all and a 60-second rest between each attempt [27]. Participants participants were tested in maximal and explosive strength were carefully instructed to contract “as fast and forcefully as and physical function tests (walking speed (preferred and possible.” *e highest force output over a three seconds maximal), stair climbing, and rising from a chair) and wore window was used in the analysis. *e rate of force devel- an accelerometer for six days to determine the physical opment (RDF) was calculated over a 200-millisecond activity. sampling window where the steepest vertical generation occurred [19]. 2.2. Participants. Due to low founding, only one munici- pality was invited to participate in this pilot study. *e 2.3.2. Physical Performance Tests. Four physical perfor- health-care services in a municipality (7000 residents) mance tests, designed to replicate daily living activities, were Journal of Aging Research 3 Number of participants who met the inclusion criteria and offered to participate in the study n =45 Number of participants who volunteered at pretest n =30 Randomizing Strength-training group (ST) Control group (CON) n =16 n =14 Dropouts Dropouts n =5 n =2 Posttest Posttest n =11 n =12 Figure 1: An overview of the study design. Table 1: Age, height, and BMI for both groups. to perform the test in the same way as they normally ascended a staircase. ST CON p value In the rising from a chair test, the participants were (n � 11) (n � 12) between groups seated in a hard-backed chair (seat height 44 cm from the Age (years) 86.5± 6.4 83.5± 5.7 0.26 floor) with their arms folded across their chest. *e par- Height (cm) 163.1± 9.5 165.4± 11.2 0.73 ticipants were instructed to rise to a full-standing position Weight (kg) 64.3± 21.2 66.6± 8.7 0.60 and return to a full-sitting position five times as fast as BMI (kg/m ) 23.9± 6.2 24.3± 1.6 0.81 possible. *e time was assessed using a stopwatch. *e ST �strength-training group; CON � control group; cm � centimetres; participants who were not able to rise without the use of aids kg � kilograms; BMI � body mass index; all values are presented as mean± standard deviation. (walker or armrests) were allowed to use the aids. conducted [14, 28, 29]. All tests were performed minimum 2.3.3. Physical Activity. Physical activity (PA) was measured twice and maximum three times based on the physical using an accelerometer (ActiGraph GT1M, ActiGraph, LLC, capacity of the participants. *e best attempt was used for Pensacola, Florida, USA) before and after the intervention. *e measures were carried out over three weekdays and the further analysis. Participants who had problems executing the tests used necessary support, that is, an aid for walking weekend (Wednesday to Sunday). Valid registrations had to represent a minimum of eight hours of valid registration per such as a stick or crutches during the walking test, handrails for stair climbing, or armrests for rising from a chair. *e use day with three approved days to be included in the analysis of support and number of attempts by each participant were [30]. *e participants were instructed to wear the acceler- noted for similar execution at posttest. 72% and 49% of the ometer on the right hip while awake and to remove the participants in the ST and the CON, respectively, needed accelerometer only during night time and during water support to perform one or more tests. activities. All registrations between 12:00 am and 06:00 am Two measurements of walking speed were carried out: were excluded [25]. Nonwear time was defined by an interval of at least 60 consecutive minutes of zero activity intensity preferred walking speed, in which the participants were instructed to walk at a pace similar to daily walking speed, counts, with allowances of 1-2 minutes of counts between 1 and 100 [30]. Based on previous studies, a 10-second epoch and maximal speed, where the participants walked as fast as they could without running. *e time was assessed by period was used [31]. Adult standard was used for overall photocells (Ergotest A/S, Porsgrunn, Norway) placed 20 physical activity level (counts per minute) in addition to meters apart along a corridor. *e first photocell was placed limits for three different intensity zones. *e intensity 2 metres in front of the start line for proper acceleration. threshold criteria were 100–2019 counts for low intensity, In the stair climbing test, the participants were instructed 2020–5999 for moderate intensity, and over 5999 counts for to ascend a staircase consisting of 16 steps with an 8 cm rise vigorous intensity. Activity under 100 counts per minute was per step as fast as possible. Time was assessed using pho- registered as inactivity [30]. *e number of steps per day tocells (Ergotest A/S, Porsgrunn, Norway) placed at the was registered using an embedded pedometer function [25]. *e software program Actilife v 6.10.1 (Actigraph, LLC, beginning and end of the staircase. *e staircase had a handrail on each side, and the participants were instructed Pensacola, Florida, USA) was used for options and analyses. 4 Journal of Aging Research the differences lay. Tests were analysed using the SPSS (SPSS 2.3.4. Intervention. *e CON group was encouraged and instructed to continue their normal activities, to stay 23; SPSS Inc., Chicago, IL USA) statistical software package and were analysed per protocol. All results are presented as physically active, and to make physically active choices. An individual conversation between the participants and mean± SD unless otherwise noted, and significant results a health professional regarding the importance of staying are presented with a Cohen’s d effect size (ES) of 0.2 con- physically active, make physically active choices, and the sidered small, 0.5 medium, and 0.8 large [33]. A p level of benefits of physical activity was conducted for the CON 0.05 was used for statistical significance. group. *e session was conducted at the beginning of the intervention period. *e conversation took place in the 3. Results residence of each participant in the CON group and lasted 3.1. Maximal Strength and Rate of Force Development (RFD). between 30 and 45 minutes. In addition, they received For the maximal strength and RFD, there was no interac- a folder from the health ministry with information, benefits, tion for the (F � 0.714–4.114, p � 0.0.3–0.409) or a main and recommendations of physical activity. effect for groups (F � 0.032–0.269, p � 0.390–0.861). With *e participants in the strength-training group per- exceptions for maximal strength in the arm (F � 1.162, formed a progressive strength-training programme twice p � 0.294), there was a main effect for time (F � 4.473– a week for 10 weeks. *e participants were instructed to 10.043, p � 0.005–0.047). After the post hoc tests, the ST perform 10–12 repetitions maximum at a controlled tempo group had a 15.3% nonsignificant improvement in the leg but concentrating on a fast explosive concentric phase and extension test (p � 0.10, ES � 0.31) and a 53.1% increase a slow eccentric phase [29]. A professional training in- for peak RFD (p � 0.04, ES � 0.69). In the elbow flexion structor was present in every training session to make sure of test, a nonsignificant 51.3% improvement for peak RFD the correct technique, intensity, and numbers of sets. *e (p � 0.08, ES � 0.60) was observed. No significant differ- training load gradually increased in numbers of sets and ences were observed for the CON (p � 0.16–1.00) (Figures 3 resistance level. *e participants were instructed to add and 4). greater resistance when they could easily perform 10–12 repetitions of a movement in the last set without significant fatigue (i.e., perform 5 extra repetitions). One–four weeks of 3.2. Physical Function. For the physical function tests, there training consisted of two sets per exercise. *e number of was no interaction (F � 0.087–2.519, p � 0.130–0.770) or sets was increased to three sets from week five and a main effect for groups (F � 1.888–2.696, p � 0.115–0.186) throughout the intervention. *e training sessions were or time (F � 0.55–2.223, p � 0.151–0.817) with one ex- performed with a training instructor present. *e partici- ception. *e stair climbing test had significant main effect pants had to attend minimum 80% of the sessions for a valid for time (F � 4.659, p � 0.044). Despite an overall im- training quantity. *e mean training attendance was 84%. provement in stair climbing of 26.6%, the improvement was *e programme consisted of five minutes of general not significant for the ST (p � 0.22). Furthermore, no sig- warmup and 40–55 minutes of strength training depending nificant difference was observed for the CON (p � 0.22). All on the number of sets. Five exercises were conducted: squats, details are presented in Table 2. box lifts, seated row, chest press, and biceps curl. Squats were performed using the body weight as resistance (Figures 2(a) and 2(b)). Box lifts were performed with a soda crate as 3.3. Physical Activity (PA). For PA, there was no interaction resistance (Figures 2(c) and 2(d)). *e external weight was (F � 0.009–0.939, p � 0.341–0.927), main effects for time gradually increased by placing 0.5 or 1 litre bottles of water (0.001–0.223, p � 0.644–0.980) or group (F � 0.120–4.178, in the crate. Elastic bands were used as resistance in the p � 0.059–0.734) for the variables overall PA, inactivity, exercises seated row, chest press, and biceps curl. *e moderate intensity, high intensity, and numbers of steps per training instructor held the elastic band for the chest and day. However, an interaction was observed for the variable rowing exercises (Figures 2(e)–2(h)). Biceps curls were low intensity (F � 5.008, p � 0.041). Post hoc tests demon- performed seated by placing the elastic band underneath the strated no differences between the groups (p � 0.480–1.000) feet of the training instructor with an equal length in each or differences between pre- and posttest (p � 0.133–0.698). hand (Figures 2(i) and 2(j)). Further, three different elastic All details are presented in Table 3. bands of assorted colours were used, with each colour denoting a different resistance level [32]. *e bands required 4. Discussion a force of approximately 79, 181, and 283 Newton, re- spectively, to stretch the bands to double their length. *e home-based strength-training intervention among frail older adults did not increase the strength but improved RFD in the lower body for the strength-training group. Fur- 2.3.5. Data Analysis. To assess differences in physical thermore, there were no significant changes in physical function, muscle strength, and physical activity, we used function, and the physical activity level was unaltered after a two-way (groups × time) within-between analysis of var- the intervention. No differences were observed in the CON iance (ANOVA) with repeated measures. When a significant group or between the groups in any of the tests. interaction was detected by ANOVA, paired t-tests with Leg extension strength increased by 15.3% in the ST Bonferroni post hoc correction were applied to locate where but only tended towards statistical significant (p � 0.100). Journal of Aging Research 5 (a) (b) (c) (d) Figure 2: Continued. 6 Journal of Aging Research (e) (f) (g) (h) (i) (j) Figure 2: (a–j) An overview of the five training exercises. Journal of Aging Research 7 250 ∗ p = 0.100 400 ST CON ST CON Pretest Pretest Posttest Posttest (a) (b) Figure 3: *e pre- and posttest results of the (a) maximal strength and (b) RFD in leg extension for the strength-training group (ST) and control group (CON). All values are presented as mean± SE. Within-group differences, p< 0.05. 140 300 p = 0.08 0 0 ST CON ST CON Pretest Pretest Posttest Posttest (a) (b) Figure 4: *e pre- and posttest results of the (a) maximal strength and (b) RFD in arm flexion for the strength-training group (ST) and control group (CON). All values are presented as mean± SE. Within-group differences, p< 0.05. None of the participants trained strength before the in- *e arm flexion strength was unaltered for the ST. tervention. *e numbers of exercises and sets were therefore Despite the participants’ effort to perform the exercises with low. Additionally, the strength-training group only trained proper execution until failure, the limited training load on twice per week. *e lack of improvement was most likely the biceps (only one isolating exercise) may explain the lack a result of low training volume, low statistical power, and of strength improvement. Furthermore, the moderate large standard deviation. *e result supports not our hy- training load using an elastic band and the choice of 10–12 repetitions in the present study may have contributed to the potheses nor previous studies despite similar improvements as comparable studies [16, 17, 34]. For example, Capodaglio lack of improvement in upper-body strength. However, the et al. demonstrated a 14.9% improvement in maximal iso- number of repetitions is recommended for novice in- metric leg extension after five months of strength training dividuals [36]. Still, the same findings were presented by performed at home using elastic bands [34]. In addition, Skelton and McLaughlin, who failed to observe an im- Frontera et al. observed an 11.9% increase in the right provement in isometric elbow flexion despite a 20% im- quadriceps cross-section area in addition to an 8.5% im- provement in leg extension after an eight-week supervised provement in dynamic muscle strength after attending training period among 80-year-olds [5]. Furthermore, Zion a 12 wk strength training program [35]. et al. used a similar training protocol as the present study 8 Journal of Aging Research Table 2: Pre- and posttest results of physical function for the ST isometric strength [40], and accordingly, there is evidence and CON. that the decline in muscle power is greater than the decline in muscle strength in the older adults [3, 43]. Older adults may Tests Group Pretest Posttest therefore have a larger potential to improve the RFD ST 26.0± 6.0 19.3± 3.4 Stair climbing (sec) compared to muscle strength. CON 18.3± 3.6 17.1± 3.3 *is study did not demonstrate a significant effect of the ST 2.3± 0.3 2.3± 0.2 Preferred walking speed (km/h) resistance training programme on functional outcome CON 3.0± 0.3 2.9± 0.3 measures. However, there was a consistent trend towards ST 3.5± 0.3 3.8± 0.4 Maximal walking speed (km/h) nonsignificant improvements in physical function by 3.5– CON 4.5± 0.4 4.3± 0.4 25.6% for the ST. Although the training programme trained ST 27.6± 4.6 25.5± 4.1 Rising from a chair (sec) the same muscles/muscles groups as the physical tests target, CON 20.6± 2.2 19.1± 2.3 the exercises might not have been specific enough to give ST �strength-training group; CON � control group; sec � seconds; km/h � significant changes in the physical functional tests [38]. kilometres per hour; all values are presented as mean± standard error. Moreover, the absence of significant changes in physical function may be explained by variability in performance, age (78–97 years), and physical characteristics at baseline. For Table 3: Pre- and posttest results of physical activity for the ST example, differences in execution of the tests due to frailty and CON. and the need for support (i.e., walking aids and the use of Tests Group Pretest Posttest handrails and armrests) may have influenced the variation in the test results within and between groups. However, the ST 57.6± 8.4 67.7± 12.5 Overall PA (cpm) CON 129.5± 25.5 120.5± 24.7 older adults with assistive devices (3 in the ST and 4 in the CON) were not significant differences in the physical ST 673.4± 16.3 688.0± 32.6 Inactivity (min/day) CON 663.1± 28.4 621.7± 31.2 function tests compared to the one without. Comparable studies have usually carried out the tests with ST 83.8± 12.8 91.1± 13.0 Low intensity (min/day) CON 120.4± 21.5 101.6± 16.4 identical execution for all participants [11, 29, 44], and this might contribute to less variation in the test results, mainly because the ST 2.9± 0.5 2.8± 0.7 Moderate intensity (min/day) participants in these studies were younger and healthier, CON 11.1± 2.8 10.7± 3.7 resulting in more homogeneity compared to the participants in ST 0.2± 0.1 0.2± 0.1 High intensity (min/day) our study. Despite the differences in execution among the CON 0.2± 0.1 0.2± 0.1 participants, the test protocol was carefully standardized and the ST 1360± 322 1262± 312 Steps (per day) use of support was noted for similar execution at pre- and CON 2868± 547 2396± 501 posttest. *e training volume was quite low (2x per week and ST �strength-training group; CON � control group; s � seconds; km/h � kilometres per hour; cpm � counts per minute; min/day � minutes per day; only 2 sets in the first weeks) due to the lack of experience with all values are presented as mean± standard error. resistance training and relative low physical function (all par- ticipants received health-care services). We cannot exclude that a higher volume may have resulted in greater benefits. with only one isolating exercise for biceps and observed no Our findings are supported by a previous study who reported no significant changes, but a tendency for im- changes in isometric handgrip [12]. Importantly, the training in the present study was performed dynamically provements in rising from a chair (10 times) and the time-up and go among frail older adults after resistance training while the tests were isometric. Previous studies have re- ported substantially lower improvement in isometric than intervention [45]. dynamic strength after a dynamic strength-training program *e physical activity level concerning inactivity and low, [37–39]. moderate, and high intensity was unaltered for both groups Our findings demonstrate that the execution of the after the intervention. However, the overall PA (counts per minute) increased with 17.4% for the ST, but not signifi- exercises, performed in a fast explosive concentric phase, contributed to the improvements in RFD. *ese results cantly. Importantly, the STmaintained their physical activity attending strength training twice per week. A systematic support our hypotheses and previous studies [18–20, 40]. *e increase in RFD in the present study may be the result of review demonstrated a compensation of physical activity in over 50% of the studies attending different training in- neurological adaptations as RFD is highly influenced by the magnitude of neuromuscular activity irrespective of age terventions [46]. Despite having benefits of participation in [41, 42]. To our knowledge, no previous studies have carried the strength-training program, the physical activity level of out RFD tests after home-based strength training using low the ST was not increased. *e physical activity results costs portable training equipment. Previous studies have supported our hypothesis that due the short intervention used traditional strength training equipment (training period, the PA level did not increase. Importantly and most machines or free weights), but the need of such facilities may likely, our findings may have been affected by the variation of the season, with pretesting being performed in late exclude several frail older adults. Comparing the strength and RFD results, the substantially lower strength im- summer and posttesting during the late autumn. In addition, the weather conditions may have influenced the activity level provement is supported by previous studies. *e im- provement in RFD has shown to increase greater than due to dry weather at pretest and precipitation/snow at Journal of Aging Research 9 posttest and might explain the nonsignificant changes. Acknowledgments Lemmer et al. demonstrated no significant changes in PA for *e authors wish to thank all the individuals who took part younger (20–30 years) or older adult (65–75 years) in- in this intervention study. dividuals after 24 weeks of strength training supporting the PA results of the present study [47]. 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Effects of Strength Training on Muscle Properties, Physical Function, and Physical Activity among Frail Older People: A Pilot Study

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Copyright © 2018 Atle Hole Saeterbakken et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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Hindawi Journal of Aging Research Volume 2018, Article ID 8916274, 11 pages https://doi.org/10.1155/2018/8916274 Clinical Study Effects of Strength Training on Muscle Properties, Physical Function, and Physical Activity among Frail Older People: A Pilot Study Atle Hole Saeterbakken , Hilde Bremseth Ba˚rdstu, Anine Brudeseth, and Vidar Andersen Faculty of Teacher Education, Culture and Sport, Western Norway University of Applied Sciences, Bergen, Norway Correspondence should be addressed to Atle Hole Saeterbakken; atle.saeterbakken@hvl.no Received 7 August 2017; Revised 2 January 2018; Accepted 30 January 2018; Published 3 June 2018 Academic Editor: Jean-Francois Grosset Copyright © 2018 Atle Hole Saeterbakken et al. *is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. *e aim of this study was to determine the effects of a 10-week strength training intervention on isometric strength, rate of force development (RFD), physical function (stair climbing, rising from a chair, and preferred and maximal walking speed), and physical activity among frail elderly people receiving home-care services. *irty participants were randomly assigned (by sex) to a control group (CON) or a strength training group (ST) performing a supervised training programme using elastic bands, box- lifting, and body weight exercises twice per week. Twenty-three participants were selected to complete the study (age 84.9± 6.1 years). For the ST, only improvement in muscle properties was the peak RFD in leg extension (p � 0.04). No significant differences were observed in muscle properties for the control group (CON) (p � 0.16–1.00) or between groups (p � 0.39–1.00). *ere were no changes within and between the groups in physical function (p � 0.12–0.19) or physical activity levels (p � 0.06–0.73). *e results of this pilot study did not demonstrate greater improvements in muscle properties and physical function and improved physical activity after attending a home-based resistance program compared to physical activity advise; however, larger population studies should examine these findings. *is trial is registered with ISRCTN10967873. lack of confidence, or inability to travel to another place. 1. Introduction Further, very few nurse-care centres have well equipped With increasing age, human skeletal muscle undergoes both strength training facilities. Recently, the interest in low-cost structural and functional changes, with a reduction in home-based intervention studies examining the older adults muscle mass and muscle strength [1, 2]. In addition, ageing has grown in popularity [11, 12]. A home-based exercise atrophy is associated with a notable decrease in maximum programme may contribute to increased participations, muscle strength, power, and rate of force development especially among frail older adults who might not have the (RFD) [3, 4]. Reduced muscle mass and muscle strength is opportunity to use gym or fitness facilities [13]. However, the associated with loss of function during typical daily living isolated effects of home-based strength training programs activities such as rising from a chair, stair climbing, and in are not conclusive and have not examined frail older adults postural balance [5]. [11, 14–17]. *erefore, pilot studies with frail older adults Strength training has improved muscle strength, muscle examining training programs (i.e., equipment, volume, mass, and physical function among older adults [6–10]. frequency, intensity, and ability to participate) need to be Traditional strength training studies with elderly people are conducted before starting large-scale studies. conducted in fitness centres with multiple training machines However, typical equipment used in home-based in- [6–10]. However, fitness centres may exclude frail older terventions studies is elastic bands, body weight exercises, adults to participate due to their functional level, discomfort, and other undersized training devices [13], and the 2 Journal of Aging Research equipment is cheap, portable, and saves space compared to informed all elderly people meeting the inclusion criteria (45 a training centre. Intervention studies for the older adults potential participants) to participate in this pilot study. 2/3 using this training equipment have found improvements in of them volunteered, and 30 community-dwelling older muscle strength [16, 17]. However, the transferability of the adults (6 male and 24 female) were recruited. *e partici- improved strength to physical function (i.e., rising from pants were stratified randomly by sex. *e name of each a chair, stair climbing, and postural balance) is not clear. participant was written on a patch and divided into two While traditional and explosive strength training improved heaps—one for each sex. *e patches were thoroughly mixed RFD by 12–50% among 60–89-year-old participants before drawing first the male and then the female to either [18–20], none of the studies examining home-based pro- a strength-training group (ST) (n � 16) or a control group grams have trained explosive strength or included mea- (CON) (n � 14). *e first, third, fifth, and more patches surement of RFD. from each heaps were assigned to the ST group and It is well documented that physical activity (PA) can remaining to the CON group. Seven participants dropped reduce the risks of chronic diseases and contribute to the out during the intervention (five from the ST and two from the CON) with reason not related to the study. Twenty-three enhancement of physical function and maintenance of in- dependence for older adults [21–23]. Overall, the PA level participants (6 male and 17 female) aged 71–97 years decreases with ageing, and only 12% of the 80–85-year-old completed the study (Figure 1). Due to the nature of the age group fulfilled the current PA recommendation of 30 intervention, neither participants nor staff were blinded to minutes of moderate daily activity [24, 25]. However, there is the group allocation or the outcome assessors. Anthropo- a lack of knowledge about the effects of low-cost home-based metric measurements for the two groups are shown in strength training and PA levels among frail older adults. Table 1. Further, the effects of home-based strength training pro- To participate in the study, the following inclusion criteria grams among community-dwelling older adults receiving had to be fulfilled: (1)>70 years of age living at home and (2) health-care services have not been properly examined as in need of home care due to functional disabilities and/or a rehabilitation strategy to prevent the age-related changes in medication. *e exclusion criteria were older adults di- agnosed with chronic mental disorders, for example, Alz- muscle properties and physical function. With a rapid in- creasing numbers of older adults in the next centuries, low- heimer’s disease or injuries and/or diagnoses not justifiable to cost and home-based rehabilitation programs need to be execute testing or training. Explanation of the purpose, examined to decrease the factors associated with needy el- procedures, potential risks, and benefits of the study was given derly being able to live independent and self-reliant of orally and in writing to all participants. A written consent was health-care services. *erefore, the aim of this study was to provided prior to testing. *e study was approved by the local conduct a pilot study to determine the possible harms or ethics committee (REK sør-øst B, 2014/1147). benefits of a home-based strength training programme on physical function tests and level of physical activity in ad- 2.3. Measures dition to muscle strength and RFD among frail old adults. Accordingly, we hypothesized that a 10-week intervention 2.3.1. Maximal Strength and Rate of Force Development could be beneficial for frail older adults by improving muscle (RFD). To test the maximal isometric force output in leg strength, peak RFD, and physical function, but not the PA extension and elbow flexion, a nonelectric sling (ROPES A/S, due to the short intervention period. Asgardstrand, Norway) was placed around the dominant ankle or hand and attached to a force cell (Ergotest A/S, Porsgrunn, Norway). *e knee and elbow angles were 2. Materials and Methods measured for each participant with a paragraph protractor. 2.1. Study Design. *e pilot study was parallel group design ° Both tests were performed with a 90 angle flexion in the where 30 community-dwelling older adults receiving health- knee or elbow joint. Performing the leg extension test, the care services were randomly assigned to either a strength- ° participants were seated with a hip angle of 90 which had to training group (ST) or a control group (CON). *e ST group be maintained during testing [15]. *e participants’ domi- performed a progressive strength-training programme twice nant hand was used to holda semisupinated grip [26], and a week with 10–12 repetitions for 10 weeks. *e CON was the elbow was held closed to the body. Each participant had instructed and encouraged to continue their normal activ- three attempts with a contraction duration of five seconds ities during the intervention. Pre- and postintervention, all and a 60-second rest between each attempt [27]. Participants participants were tested in maximal and explosive strength were carefully instructed to contract “as fast and forcefully as and physical function tests (walking speed (preferred and possible.” *e highest force output over a three seconds maximal), stair climbing, and rising from a chair) and wore window was used in the analysis. *e rate of force devel- an accelerometer for six days to determine the physical opment (RDF) was calculated over a 200-millisecond activity. sampling window where the steepest vertical generation occurred [19]. 2.2. Participants. Due to low founding, only one munici- pality was invited to participate in this pilot study. *e 2.3.2. Physical Performance Tests. Four physical perfor- health-care services in a municipality (7000 residents) mance tests, designed to replicate daily living activities, were Journal of Aging Research 3 Number of participants who met the inclusion criteria and offered to participate in the study n =45 Number of participants who volunteered at pretest n =30 Randomizing Strength-training group (ST) Control group (CON) n =16 n =14 Dropouts Dropouts n =5 n =2 Posttest Posttest n =11 n =12 Figure 1: An overview of the study design. Table 1: Age, height, and BMI for both groups. to perform the test in the same way as they normally ascended a staircase. ST CON p value In the rising from a chair test, the participants were (n � 11) (n � 12) between groups seated in a hard-backed chair (seat height 44 cm from the Age (years) 86.5± 6.4 83.5± 5.7 0.26 floor) with their arms folded across their chest. *e par- Height (cm) 163.1± 9.5 165.4± 11.2 0.73 ticipants were instructed to rise to a full-standing position Weight (kg) 64.3± 21.2 66.6± 8.7 0.60 and return to a full-sitting position five times as fast as BMI (kg/m ) 23.9± 6.2 24.3± 1.6 0.81 possible. *e time was assessed using a stopwatch. *e ST �strength-training group; CON � control group; cm � centimetres; participants who were not able to rise without the use of aids kg � kilograms; BMI � body mass index; all values are presented as mean± standard deviation. (walker or armrests) were allowed to use the aids. conducted [14, 28, 29]. All tests were performed minimum 2.3.3. Physical Activity. Physical activity (PA) was measured twice and maximum three times based on the physical using an accelerometer (ActiGraph GT1M, ActiGraph, LLC, capacity of the participants. *e best attempt was used for Pensacola, Florida, USA) before and after the intervention. *e measures were carried out over three weekdays and the further analysis. Participants who had problems executing the tests used necessary support, that is, an aid for walking weekend (Wednesday to Sunday). Valid registrations had to represent a minimum of eight hours of valid registration per such as a stick or crutches during the walking test, handrails for stair climbing, or armrests for rising from a chair. *e use day with three approved days to be included in the analysis of support and number of attempts by each participant were [30]. *e participants were instructed to wear the acceler- noted for similar execution at posttest. 72% and 49% of the ometer on the right hip while awake and to remove the participants in the ST and the CON, respectively, needed accelerometer only during night time and during water support to perform one or more tests. activities. All registrations between 12:00 am and 06:00 am Two measurements of walking speed were carried out: were excluded [25]. Nonwear time was defined by an interval of at least 60 consecutive minutes of zero activity intensity preferred walking speed, in which the participants were instructed to walk at a pace similar to daily walking speed, counts, with allowances of 1-2 minutes of counts between 1 and 100 [30]. Based on previous studies, a 10-second epoch and maximal speed, where the participants walked as fast as they could without running. *e time was assessed by period was used [31]. Adult standard was used for overall photocells (Ergotest A/S, Porsgrunn, Norway) placed 20 physical activity level (counts per minute) in addition to meters apart along a corridor. *e first photocell was placed limits for three different intensity zones. *e intensity 2 metres in front of the start line for proper acceleration. threshold criteria were 100–2019 counts for low intensity, In the stair climbing test, the participants were instructed 2020–5999 for moderate intensity, and over 5999 counts for to ascend a staircase consisting of 16 steps with an 8 cm rise vigorous intensity. Activity under 100 counts per minute was per step as fast as possible. Time was assessed using pho- registered as inactivity [30]. *e number of steps per day tocells (Ergotest A/S, Porsgrunn, Norway) placed at the was registered using an embedded pedometer function [25]. *e software program Actilife v 6.10.1 (Actigraph, LLC, beginning and end of the staircase. *e staircase had a handrail on each side, and the participants were instructed Pensacola, Florida, USA) was used for options and analyses. 4 Journal of Aging Research the differences lay. Tests were analysed using the SPSS (SPSS 2.3.4. Intervention. *e CON group was encouraged and instructed to continue their normal activities, to stay 23; SPSS Inc., Chicago, IL USA) statistical software package and were analysed per protocol. All results are presented as physically active, and to make physically active choices. An individual conversation between the participants and mean± SD unless otherwise noted, and significant results a health professional regarding the importance of staying are presented with a Cohen’s d effect size (ES) of 0.2 con- physically active, make physically active choices, and the sidered small, 0.5 medium, and 0.8 large [33]. A p level of benefits of physical activity was conducted for the CON 0.05 was used for statistical significance. group. *e session was conducted at the beginning of the intervention period. *e conversation took place in the 3. Results residence of each participant in the CON group and lasted 3.1. Maximal Strength and Rate of Force Development (RFD). between 30 and 45 minutes. In addition, they received For the maximal strength and RFD, there was no interac- a folder from the health ministry with information, benefits, tion for the (F � 0.714–4.114, p � 0.0.3–0.409) or a main and recommendations of physical activity. effect for groups (F � 0.032–0.269, p � 0.390–0.861). With *e participants in the strength-training group per- exceptions for maximal strength in the arm (F � 1.162, formed a progressive strength-training programme twice p � 0.294), there was a main effect for time (F � 4.473– a week for 10 weeks. *e participants were instructed to 10.043, p � 0.005–0.047). After the post hoc tests, the ST perform 10–12 repetitions maximum at a controlled tempo group had a 15.3% nonsignificant improvement in the leg but concentrating on a fast explosive concentric phase and extension test (p � 0.10, ES � 0.31) and a 53.1% increase a slow eccentric phase [29]. A professional training in- for peak RFD (p � 0.04, ES � 0.69). In the elbow flexion structor was present in every training session to make sure of test, a nonsignificant 51.3% improvement for peak RFD the correct technique, intensity, and numbers of sets. *e (p � 0.08, ES � 0.60) was observed. No significant differ- training load gradually increased in numbers of sets and ences were observed for the CON (p � 0.16–1.00) (Figures 3 resistance level. *e participants were instructed to add and 4). greater resistance when they could easily perform 10–12 repetitions of a movement in the last set without significant fatigue (i.e., perform 5 extra repetitions). One–four weeks of 3.2. Physical Function. For the physical function tests, there training consisted of two sets per exercise. *e number of was no interaction (F � 0.087–2.519, p � 0.130–0.770) or sets was increased to three sets from week five and a main effect for groups (F � 1.888–2.696, p � 0.115–0.186) throughout the intervention. *e training sessions were or time (F � 0.55–2.223, p � 0.151–0.817) with one ex- performed with a training instructor present. *e partici- ception. *e stair climbing test had significant main effect pants had to attend minimum 80% of the sessions for a valid for time (F � 4.659, p � 0.044). Despite an overall im- training quantity. *e mean training attendance was 84%. provement in stair climbing of 26.6%, the improvement was *e programme consisted of five minutes of general not significant for the ST (p � 0.22). Furthermore, no sig- warmup and 40–55 minutes of strength training depending nificant difference was observed for the CON (p � 0.22). All on the number of sets. Five exercises were conducted: squats, details are presented in Table 2. box lifts, seated row, chest press, and biceps curl. Squats were performed using the body weight as resistance (Figures 2(a) and 2(b)). Box lifts were performed with a soda crate as 3.3. Physical Activity (PA). For PA, there was no interaction resistance (Figures 2(c) and 2(d)). *e external weight was (F � 0.009–0.939, p � 0.341–0.927), main effects for time gradually increased by placing 0.5 or 1 litre bottles of water (0.001–0.223, p � 0.644–0.980) or group (F � 0.120–4.178, in the crate. Elastic bands were used as resistance in the p � 0.059–0.734) for the variables overall PA, inactivity, exercises seated row, chest press, and biceps curl. *e moderate intensity, high intensity, and numbers of steps per training instructor held the elastic band for the chest and day. However, an interaction was observed for the variable rowing exercises (Figures 2(e)–2(h)). Biceps curls were low intensity (F � 5.008, p � 0.041). Post hoc tests demon- performed seated by placing the elastic band underneath the strated no differences between the groups (p � 0.480–1.000) feet of the training instructor with an equal length in each or differences between pre- and posttest (p � 0.133–0.698). hand (Figures 2(i) and 2(j)). Further, three different elastic All details are presented in Table 3. bands of assorted colours were used, with each colour denoting a different resistance level [32]. *e bands required 4. Discussion a force of approximately 79, 181, and 283 Newton, re- spectively, to stretch the bands to double their length. *e home-based strength-training intervention among frail older adults did not increase the strength but improved RFD in the lower body for the strength-training group. Fur- 2.3.5. Data Analysis. To assess differences in physical thermore, there were no significant changes in physical function, muscle strength, and physical activity, we used function, and the physical activity level was unaltered after a two-way (groups × time) within-between analysis of var- the intervention. No differences were observed in the CON iance (ANOVA) with repeated measures. When a significant group or between the groups in any of the tests. interaction was detected by ANOVA, paired t-tests with Leg extension strength increased by 15.3% in the ST Bonferroni post hoc correction were applied to locate where but only tended towards statistical significant (p � 0.100). Journal of Aging Research 5 (a) (b) (c) (d) Figure 2: Continued. 6 Journal of Aging Research (e) (f) (g) (h) (i) (j) Figure 2: (a–j) An overview of the five training exercises. Journal of Aging Research 7 250 ∗ p = 0.100 400 ST CON ST CON Pretest Pretest Posttest Posttest (a) (b) Figure 3: *e pre- and posttest results of the (a) maximal strength and (b) RFD in leg extension for the strength-training group (ST) and control group (CON). All values are presented as mean± SE. Within-group differences, p< 0.05. 140 300 p = 0.08 0 0 ST CON ST CON Pretest Pretest Posttest Posttest (a) (b) Figure 4: *e pre- and posttest results of the (a) maximal strength and (b) RFD in arm flexion for the strength-training group (ST) and control group (CON). All values are presented as mean± SE. Within-group differences, p< 0.05. None of the participants trained strength before the in- *e arm flexion strength was unaltered for the ST. tervention. *e numbers of exercises and sets were therefore Despite the participants’ effort to perform the exercises with low. Additionally, the strength-training group only trained proper execution until failure, the limited training load on twice per week. *e lack of improvement was most likely the biceps (only one isolating exercise) may explain the lack a result of low training volume, low statistical power, and of strength improvement. Furthermore, the moderate large standard deviation. *e result supports not our hy- training load using an elastic band and the choice of 10–12 repetitions in the present study may have contributed to the potheses nor previous studies despite similar improvements as comparable studies [16, 17, 34]. For example, Capodaglio lack of improvement in upper-body strength. However, the et al. demonstrated a 14.9% improvement in maximal iso- number of repetitions is recommended for novice in- metric leg extension after five months of strength training dividuals [36]. Still, the same findings were presented by performed at home using elastic bands [34]. In addition, Skelton and McLaughlin, who failed to observe an im- Frontera et al. observed an 11.9% increase in the right provement in isometric elbow flexion despite a 20% im- quadriceps cross-section area in addition to an 8.5% im- provement in leg extension after an eight-week supervised provement in dynamic muscle strength after attending training period among 80-year-olds [5]. Furthermore, Zion a 12 wk strength training program [35]. et al. used a similar training protocol as the present study 8 Journal of Aging Research Table 2: Pre- and posttest results of physical function for the ST isometric strength [40], and accordingly, there is evidence and CON. that the decline in muscle power is greater than the decline in muscle strength in the older adults [3, 43]. Older adults may Tests Group Pretest Posttest therefore have a larger potential to improve the RFD ST 26.0± 6.0 19.3± 3.4 Stair climbing (sec) compared to muscle strength. CON 18.3± 3.6 17.1± 3.3 *is study did not demonstrate a significant effect of the ST 2.3± 0.3 2.3± 0.2 Preferred walking speed (km/h) resistance training programme on functional outcome CON 3.0± 0.3 2.9± 0.3 measures. However, there was a consistent trend towards ST 3.5± 0.3 3.8± 0.4 Maximal walking speed (km/h) nonsignificant improvements in physical function by 3.5– CON 4.5± 0.4 4.3± 0.4 25.6% for the ST. Although the training programme trained ST 27.6± 4.6 25.5± 4.1 Rising from a chair (sec) the same muscles/muscles groups as the physical tests target, CON 20.6± 2.2 19.1± 2.3 the exercises might not have been specific enough to give ST �strength-training group; CON � control group; sec � seconds; km/h � significant changes in the physical functional tests [38]. kilometres per hour; all values are presented as mean± standard error. Moreover, the absence of significant changes in physical function may be explained by variability in performance, age (78–97 years), and physical characteristics at baseline. For Table 3: Pre- and posttest results of physical activity for the ST example, differences in execution of the tests due to frailty and CON. and the need for support (i.e., walking aids and the use of Tests Group Pretest Posttest handrails and armrests) may have influenced the variation in the test results within and between groups. However, the ST 57.6± 8.4 67.7± 12.5 Overall PA (cpm) CON 129.5± 25.5 120.5± 24.7 older adults with assistive devices (3 in the ST and 4 in the CON) were not significant differences in the physical ST 673.4± 16.3 688.0± 32.6 Inactivity (min/day) CON 663.1± 28.4 621.7± 31.2 function tests compared to the one without. Comparable studies have usually carried out the tests with ST 83.8± 12.8 91.1± 13.0 Low intensity (min/day) CON 120.4± 21.5 101.6± 16.4 identical execution for all participants [11, 29, 44], and this might contribute to less variation in the test results, mainly because the ST 2.9± 0.5 2.8± 0.7 Moderate intensity (min/day) participants in these studies were younger and healthier, CON 11.1± 2.8 10.7± 3.7 resulting in more homogeneity compared to the participants in ST 0.2± 0.1 0.2± 0.1 High intensity (min/day) our study. Despite the differences in execution among the CON 0.2± 0.1 0.2± 0.1 participants, the test protocol was carefully standardized and the ST 1360± 322 1262± 312 Steps (per day) use of support was noted for similar execution at pre- and CON 2868± 547 2396± 501 posttest. *e training volume was quite low (2x per week and ST �strength-training group; CON � control group; s � seconds; km/h � kilometres per hour; cpm � counts per minute; min/day � minutes per day; only 2 sets in the first weeks) due to the lack of experience with all values are presented as mean± standard error. resistance training and relative low physical function (all par- ticipants received health-care services). We cannot exclude that a higher volume may have resulted in greater benefits. with only one isolating exercise for biceps and observed no Our findings are supported by a previous study who reported no significant changes, but a tendency for im- changes in isometric handgrip [12]. Importantly, the training in the present study was performed dynamically provements in rising from a chair (10 times) and the time-up and go among frail older adults after resistance training while the tests were isometric. Previous studies have re- ported substantially lower improvement in isometric than intervention [45]. dynamic strength after a dynamic strength-training program *e physical activity level concerning inactivity and low, [37–39]. moderate, and high intensity was unaltered for both groups Our findings demonstrate that the execution of the after the intervention. However, the overall PA (counts per minute) increased with 17.4% for the ST, but not signifi- exercises, performed in a fast explosive concentric phase, contributed to the improvements in RFD. *ese results cantly. Importantly, the STmaintained their physical activity attending strength training twice per week. A systematic support our hypotheses and previous studies [18–20, 40]. *e increase in RFD in the present study may be the result of review demonstrated a compensation of physical activity in over 50% of the studies attending different training in- neurological adaptations as RFD is highly influenced by the magnitude of neuromuscular activity irrespective of age terventions [46]. Despite having benefits of participation in [41, 42]. To our knowledge, no previous studies have carried the strength-training program, the physical activity level of out RFD tests after home-based strength training using low the ST was not increased. *e physical activity results costs portable training equipment. Previous studies have supported our hypothesis that due the short intervention used traditional strength training equipment (training period, the PA level did not increase. Importantly and most machines or free weights), but the need of such facilities may likely, our findings may have been affected by the variation of the season, with pretesting being performed in late exclude several frail older adults. Comparing the strength and RFD results, the substantially lower strength im- summer and posttesting during the late autumn. In addition, the weather conditions may have influenced the activity level provement is supported by previous studies. *e im- provement in RFD has shown to increase greater than due to dry weather at pretest and precipitation/snow at Journal of Aging Research 9 posttest and might explain the nonsignificant changes. Acknowledgments Lemmer et al. demonstrated no significant changes in PA for *e authors wish to thank all the individuals who took part younger (20–30 years) or older adult (65–75 years) in- in this intervention study. dividuals after 24 weeks of strength training supporting the PA results of the present study [47]. 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