Effectiveness of combined exercise training to improve functional fitness in older adults: A randomized controlled trial

bs_bs_banner Geriatr Gerontol Int 2014; 14: 892–898 ORIGINAL ARTICLE: EPIDEMIOLOGY, CLINICAL PRACTICE AND HEALTH Effectiveness of combined exercise...
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Geriatr Gerontol Int 2014; 14: 892–898

ORIGINAL ARTICLE: EPIDEMIOLOGY, CLINICAL PRACTICE AND HEALTH

Effectiveness of combined exercise training to improve functional fitness in older adults: A randomized controlled trial Nelson Sousa,1 Romeu Mendes,1 Catarina Abrantes,1 Jaime Sampaio1 and José Oliveira2 Research Center in Sport Sciences, Health Sciences and Human Development, University of Trás-os-Montes e Alto Douro, Vila Real, and Research Center in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Porto, Portugal

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Aim: The present randomized controlled trial evaluated the impact of different exercise training modalities on functional fitness responses in apparently healthy older men. Methods: A total of 59 community-dwelling older men were randomly assigned to an aerobic training group (ATG, n = 19), a combined aerobic and resistance training group (CTG, n = 20) or a control group (n = 20). Both exercise training programs were moderate-to-vigorous intensity, 3 days/week for 9 months. Six independent functional fitness tests (back scratch, chair sit-and-reach, 30-s chair stand, arm curl, 8-ft up-and-go, 6-min walk) were measured on five different occasions. The data were analyzed using a mixed-model ANOVA. Results: ANOVA showed a significant main effect of group (P < 0.001) for all functional fitness tests, with significant differences between both training groups and controls. However, the ATG only improved the chair sit-and-reach and the 30-s chair stand performance, whereas CTG improved in all functional fitness tests. ANOVA also identified a significant main effect of time for 8-ft up-and-go (P = 0.031) in the CTG. Conclusions: Only the combined exercise program was effective in improving all functional fitness components related to daily living activities. Geriatr Gerontol Int 2014; 14: 892–898. Keywords: combined training, functional fitness, prolonged exercise.

Introduction Aging is accompanied by a progressive decline in functional fitness,1,2 which is a powerful and independent risk factor for premature mortality.3 Functional fitness is generally defined as the ability to independently carry out daily living activities without difficulty.4,5 Low fitness in older adults is associated with a higher rate of decline in lean mass and increases in body fat, abnormal metabolic profile, increases in blood pressure and arterial stiffness, deregulation of autonomic function, and cardiac pressure overload, which impacts significantly on quality of life.6–9 Therefore, muscle mass, muscular strength, muscular flexibility, muscular endurance and cardiorespiratory fitness are important components of Accepted for publication 3 October 2013. Correspondence: Dr Nelson Sousa PhD, Parque Desportivo da UTAD, Apartado 1013, Vila Real 5001-801, Portugal. Email [email protected] Trial Registration: clinicaltrials.gov Identifier: NCT01874132.

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doi: 10.1111/ggi.12188

functional fitness in older adults, as they might be the major causes of limited mobility and activity, as well as the higher incidence of health risk factors.4 Therefore, functional fitness assessment tests in older adults should be able to determine the capacity levels of the individual strength, endurance, flexibility and sufficient mobility capacity to ascertain the risks for healthy aging.5,10 There are many reports showing that regular exercise improves functional fitness in older adults.11–14 However, continuing to identify and refine the efficiency to improve functional fitness is of substantial public health importance. The American College of Sports Medicine have recommended 20–30 min of moderate-to-vigorous aerobic training for the elderly at least 3 days a week, and the inclusion of resistance training 1 or 2 days a week.15,16 However, many participants could not comply with the aforementioned exercise frequency, so the combination of both exercise modes in three weekly sessions might potentially be a feasible and effective alternative exercise program. There are relatively few randomized © 2014 Japan Geriatrics Society

Exercise effects on functional fitness

controlled studies investigating the longitudinal effects of different exercise training programs on functional fitness. Therefore, the purpose of the present study was to evaluate in advanced older aged men the long-term changes in functional fitness by comparing aerobic training with combined aerobic and resistance training.

Methods Participants The recruitment of individuals for a 9-month study was made through the records of the City Council (Maia, Portugal), and an invitation to participate was made by telephone. A total of 89 volunteers were assessed for verification of eligibility. Inclusion criteria included men aged between 65–79 years-of-age, living independently, with no history of previous exercise training or recre-

ational sports practice, and with medical approval for exercise. Exclusion criteria were the following: smoking; diabetes; severe obesity; severe hypertension; history of falls; and those with neurological, mental or cognitive disorders, and orthopedic, pulmonary or cardiac problems (e.g. arrhythmias, history of angina, myocardial infarction, coronary bypass surgery, valvular disease) that could restrict their participation in exercise. A total of 59 older men (aged 69.1 ± 5.0 years) were randomly assigned to three groups: 19 to an aerobic training group (ATG; aged 71.7 ± 4.7 years; body mass index [BMI] = 28.0 ± 3.5 kg/m2); 20 to a combined aerobic and resistance training group (CTG; aged 68.5 ± 3.5 years; BMI = 26.4 ± 2.5 kg/m2); and 20 to a non-exercising control group (CON; aged 69.0 ± 3.7 years; BMI = 27.1 ± 3.2 kg/m2). A summary of the recruitment strategy and allocation is presented in Figure 1.

Figure 1 Consolidated Standards of Reporting Trials diagram showing the flow of participants through the study. © 2014 Japan Geriatrics Society

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All participants were instructed to continue their normal medication and dietary patterns during the course of the study. Furthermore, participants did not receive any nutritional counseling. Both verbal and written consents were obtained from each participant before testing and training, all were informed of the objectives, procedures and potential risk or discomfort. The study was approved by the University of Trás-os-Montes e Alto Douro review board for human subjects (ref. 001.032011), according to the Helsinki Declaration.

Training program protocols Both training programs consisted of three sessions each week for 32 consecutive weeks and were planned to be of moderate-to-vigorous intensity. According to the latest position stand from the American College of Sports Medicine,15 moderate intensity represents a perceived exertion of 12–13 points (Borg scale of 6–20)17 and a range on 50–69% of one-repetition maximum (1-RM). The vigorous intensity represents a perceived exertion of 14–17 points and a range of 70–84% of 1-RM. The average adherence rate to all training sessions was 82% in the ATG and 86% in the CTG; however, the participants were informed that a minimum of 77 sessions during the 32 weeks (80% compliance) was required to be included in the analysis. Before training, all participants received 2 weeks of familiarization sessions with the training equipment and exercises to be used in the intervention. All sessions lasted approximately 60 min and were always supervised by a professionally qualified instructor.

Aerobic training program The ATG trained twice per week in a land environment (Mondays and Wednesdays), and once per week in an aquatic environment (Fridays), with training sessions separated by a minimum of 48 h. This program was divided into four microcycles with different routines applied every 8 weeks (microcycle I: weeks 1–8; microcycle II: weeks 8–16; microcycle III: weeks 16–24; microcycle IV: weeks 24–32). All aerobic training sessions consisted of: (i) a 10-min warm-up period, which included walking and flexibility exercises; (ii) a 30-min cardiorespiratory period, including walking and/or jogging and/or dancing patterns, with intensity perceived as moderate; (iii) a 10-min muscular endurance, which included three exercises (3 sets, 15–20 repetitions) using only bodyweight and gravity for strengthening the lower and upper limbs in a land environment, and water resistance in an aquatic environment; and (iv) a 5-min cool-down period, which included breathing and stretching exercises. When the aerobic training ses894 |

sions were carried out exclusively in the aquatic environment, agility exercises were carried out in a ludic game format (e.g. relay races, water volleyball and water polo), lasting approximately 10 min. These were carried out after the flexibility workout and before the cooldown period.

Combined training program The training sessions for the CTG included the same format as aforementioned. However, the aerobic training sessions on Mondays were replaced by a resistance training session. The intensity of the resistance training sessions was set to 65% of 1-RM on the first 8 weeks (3 sets, 10–12 repetitions); 75% of 1-RM for weeks 8–24 (3 sets, 8–10 repetitions); 70% of 1-RM for weeks 24–28 (3 sets, 8–10 repetitions); and 65% of 1-RM for weeks 28–32 (3 sets, 10–12 repetitions). Rest periods between sets were 30 s long, and between exercises 1 min long. Each session always began with a 10-min warm-up on either a bicycle ergometer or treadmill at low-work level, followed by static stretching exercises. The main part of the sessions consisted of a circuit of seven exercises: bench press, leg press, lateral pull-down, leg extension, military press, leg curl and arm curl, in this order, and carried out with conventional variable resistance devices (Fitline 2000 series; Panatta Sport, Apiro, Italy). In addition, the participants carried out floor exercises for the abdominals and erector spinae muscle groups, and ended with a cool-down period, which included breathing and stretching exercises. To control the target intensity of the different training programs, all participants at all training sessions recorded the values of perceived exertion using the Borg scale.11

Measurements Each participant reported to the facilities at 07.00 hours on five separate occasions (baseline, after 8 weeks, after 16 weeks, after 24 weeks and after 32 weeks). Height and weight were measured on a standard scale with a stadiometer (SECA 770; Seca Corporation, Hamburg, Germany), and BMI was further calculated using the standard formula: weight (kg) / height2 (m).

Functional fitness Functional fitness was assessed using the Senior Fitness Test battery, which consisted of six items, designed and validated to assess the physiological parameters that support physical mobility in older adults.4,5 Rikli and Jones reported a high validity coefficient (c) for older men in all tests (c ≥ 0.75).4,5 Physical fitness parameters selected were lower and upper body strength, lower and upper body flexibility, agility/dynamic balance and © 2014 Japan Geriatrics Society

Exercise effects on functional fitness

aerobic endurance. The items were evaluated, respectively, by the following tests: 30-s chair stand (repetitions), arm curl (repetitions), chair sit-and-reach (cm), back scratch (cm), 8-ft up-and-go (s) and 6-min walk (m), always in this order. Each test was carried out according to the instructions given by its authors.4 Before the test, participants did a standard 5–10-min warm-up including stretching exercises. All the tests, except the 6-min walk test, were carried out twice and the best score registered.

Maximum strength As it was expected that the CTG participants increase their maximum strength during the resistance training sessions, 1-RM values were taken for each exercise at the first workout of week 1, week 8, week 16 and week 24, and at the last workout of week 32, allowing periodic adjustment of the resistance training intensity. The 1-RM test was measured only for the CTG and always by the same instructor.

Statistical analysis Normal distribution was tested with the Shapiro–Wilk test, and the skewness and kurtosis indices were analyzed. Because of its non-parametric distribution, a logarithmic transformation was applied to the 30-s chair

stand; however, the results are presented in the original units for comparison with other studies. Mixed-model analysis of variance (ANOVA) was carried out to test the effects of group, time and between group × time for all functional fitness tests. A Bonferroni test was used for post-hoc comparisons. The differences in 1-RM performance across the resistance training sessions were tested by repeatedmeasures ANOVA. Eta squared (η2) effect sizes were calculated to determine the magnitude of the effects. All data were analyzed using the statistical software IBM SPSS Statistics for Macintosh, version 19.0.0 (SPSS, Chicago, IL, USA), and the level of statistical significance was set at P < 0.05.

Results Figure 1 shows the flow of participants through the study. A total of 48 participants completed the 9-month study and were included in the analysis. The arithmetic mean of perceived exertion reported by all participants in all training sessions were between 11.0 ± 2.9 to 12.9 ± 1.5 points in the land aerobic training, 13.2 ± 0.7 to 13.7 ± 0.8 points in the aquatic aerobic training, and 13.4 ± 1.3 to 14.1 ± 1.5 points in the resistance training. Descriptive characteristics at baseline and absolute changes during the study period are shown in Table 1.

Table 1 Absolute functional fitness tests performance measurements for the aerobic training group (n = 15), combined training group (n = 16) and control group (n = 17) over 32 weeks

Back scratch (cm)

Chair sit-and-reach (cm)

30-s chair stand (rps)

Arm curl (rps)

8-ft up-and-go (s)

6-min walk (m)

ATG CTG CON ATG CTG CON ATG CTG CON ATG CTG CON ATG CTG CON ATG CTG CON

Absolute changes across time Baseline Week 8

Week 16

Week 24

Week 32

−25.1 ± 11.7 −18.0 ± 9.1 −17.5 ± 10.1 −7.0 ± 12.4 −5.9 ± 11.8 −10.8 ± 8.5 15.2 ± 3.3 15.9 ± 2.1 13.9 ± 1.7 17.9 ± 3.5 19.4 ± 3.6 19.0 ± 2.6 6.3 ± 0.9 5.9 ± 0.9 6.2 ± 0.7 538.3 ± 49.0 591.3 ± 80.8 578.8 ± 58.9

−24.3 ± 8.5 −14.6 ± 9.6 −20.2 ± 11.6 −5.6 ± 11.0 −1.9 ± 10.6 −13.4 ± 9.6 14.7 ± 1.6 16.4 ± 3.2 13.6 ± 1.6 19.0 ± 3.8 23.1 ± 4.0 18.5 ± 2.4 5.9 ± 0.9 5.5 ± 1.1 6.1 ± 0.8 571.1 ± 42.8 617.7 ± 77.7 575.7 ± 60.3

−21.0 ± 9.2 −14.6 ± 9.6 −19.3 ± 11.1 −6.8 ± 9.7 −3.5 ± 12.0 −15.8 ± 8.9 14.6 ± 1.5 16.1 ± 3.3 13.2 ± 2.0 18.2 ± 3.2 21.1 ± 3.8 17.5 ± 2.0 6.0 ± 0.5 5.5 ± 1.0 6.2 ± 0.7 579.0 ± 47.8 613.4 ± 76.7 580.3 ± 62.4

−19.4 ± 8.8 −11.9 ± 9.6 −20.5 ± 10.4 −3.1 ± 7.5 −0.7 ± 12.3 −15.5 ± 8.7 17.0 ± 4.4 18.3 ± 3.8 12.9 ± 2.1 20.1 ± 3.2 23.2 ± 3.1 17.3 ± 2.8 5.8 ± 0.6 5.3 ± 0.7 6.3 ± 0.9 567.8 ± 56.8 616.9 ± 70.8 559.8 ± 65.1

−24.0 ± 8.7 −18.3 ± 9.6 −19.0 ± 11.2 −4.6 ± 10.9 −0.7 ± 9.6 −11.3 ± 8.7 15.2 ± 3.3 16.9 ± 2.9 14.6 ± 3.3 19.4 ± 4.4 22.7 ± 5.1 18.9 ± 3.0 5.7 ± 0.6 5.2 ± 1.1* 5.8 ± 0.7 564.6 ± 50.9 609.4 ± 80.0 578.3 ± 56.8

*Significant different from baseline, P < 0.05. Values represents means ± standard deviation. © 2014 Japan Geriatrics Society

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At baseline, no significant differences across groups were observed in the functional tests performance. The results of ANOVA show a significant main effect of group (P < 0.001) for all functional fitness tests. After 32 weeks of exercise training, significant differences were identified in the 30-s chair stand performance between the ATG and CON, and significant differences were identified in all tests between the CTG and CON. Furthermore, significant differences were identified in the arm curl, chair sit-and-reach, back scratch, 8-ft up-and-go, and 6-min walk tests performance between the CTG and ATG. ANOVA also identified a significant main effect of time for 8-ft up-and-go (P = 0.031) in the CTG, with significant differences between baseline and week 8, but not a significant main effect of group × time interaction. Table 2 shows the summary of the mixed-model ANOVA. In 1-RM bench press, leg press, lateral pull-down, leg extension, military press and leg curl, repeatedmeasures ANOVA showed significant differences between baseline 1-RM values, and 8 week, 16 week, 24 week, and 32 week post-tests (P < 0.01). Whereas in 1-RM arm curl, ANOVA showed significant differences between baseline 1-RM values, 24 week later post-test and 32 week later post-test (P < 0.05). Table 3 shows the absolute mean values and the mean percentage gains of all 1-RM measures in the CTG.

Table 2 Mixed-model analysis of variance results for all functional fitness tests

Back scratch

Group Time Group × time Group Time Group × time Group Time Group × time Group Time Group × time Group Time Group × time Group Time Group × time

Chair sit-and-reach

30–s chair stand

Arm curl

8-ft up-and-go

6–min walk

F

P

7.3 1.1 0.7 23.6 0.6 0.6 27.8 1.5 1.4 25.2 2.3 1.9 11.5 2.8 0.4 9.8 0.7 0.4

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