bs_bs_banner
Geriatr Gerontol Int 2015
ORIGINAL ARTICLE: EPIDEMIOLOGY, CLINICAL PRACTICE AND HEALTH
Effect of resistance training using bodyweight in the elderly: Comparison of resistance exercise movement between slow and normal speed movement Yuya Watanabe,1,2 Michiya Tanimoto,3 Naoko Oba,4 Kiyoshi Sanada,5 Motohiko Miyachi6 and Naokata Ishii4 1
Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 2Faculty of Bioenvironmental Science, Kyotogakuen University, Kyoto, 3Faculty of Biology-Oriented Science and Technology, Kinki University, Wakayama, 4Department of Life Sciences, The University of Tokyo, Tokyo, 5College of Sport and Health Sciences, Ritsumeikan University, Shiga, and 6Divison of Health Promotion and Exercise, National Institutes of Health and Nutrition, Tokyo, Japan
Aim: The present study investigated whether a slow movement protocol can be applied to resistance training using bodyweight. In addition, the intervention program combined plyometric exercise with resistance exercise to improve physical function overall. Methods: A total of 39 active elderly adults participated in a 16-week intervention. The program consisted of five resistance exercises and four plyometric exercises using their own bodyweight with a single set for each exercise. Participants were assigned to one of two experimental groups. One group carried out resistance exercise with slow movement and tonic force generation (3-s concentric, 3-s eccentric and 1-s isometric actions with no rest between each repetition). The other group as a movement comparison followed the same regimen, but at normal speed (1-s eccentric and 1-s concentric actions with 1-s rest between each repetition). Muscle size, strength and physical function were measured before and after the intervention period. Results: After the intervention, strengths of upper and lower limbs, and maximum leg extensor power were significantly improved in both groups. Muscle size did not change in either group. There were no significant differences in any of the parameters between groups. Conclusions: The intervention program using only own bodyweight that comprised resistance exercise with slow movement and plyometric exercise can improve physical function in the elderly, even with single sets for each exercise. However, there was no enhanced muscle hypertrophic effect. Further attempts, such as increasing performing multiple sets, would be required to induce muscle hypertrophy. Geriatr Gerontol Int 2015; ••: ••–••. Keywords: low-intensity resistance training, sarcopenia, strength training.
Introduction Sarcopenia, the aging-related loss of muscle mass and/or strength,1–3 is associated with the risk of falls and fractures, physical disability, loss of independence, lifestyle-related diseases, and mortality.4–10 Thus, skelAccepted for publication 13 October 2014. Correspondence: Dr Yuya Watanabe PhD, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamikyo-ku, Kyoto 602-8566, Japan. Email: [email protected] At the time of intervention, Watanabe was at the Department of Life Sciences, The University of Tokyo. Tanimoto was at the Division of Health Promotion and Exercise, National Institutes of Health and Nutrition.
© 2015 Japan Geriatrics Society
etal muscle mass and strength are important factors for maintaining independence and quality of life in older individuals. To increase muscle mass and strength in older people, resistance training has been considered the most effective intervention.11,12 Although high-intensity resistance training has been used extensively to increase muscle mass and strength,13 exercise with large mechanical stress might be associated with a risk of orthopedic injury14 and markedly increased systolic blood pressure.15 In addition, these resistance training programs require special equipment, exercise facilities and supervised instruction in most cases. Therefore, it is difficult to carry out normal high-intensity resistance training for many elderly individuals, although this program is highly effective for preventing sarcopenia. doi: 10.1111/ggi.12427
|
1
Y Watanabe et al.
Recent studies have reported that relatively lowintensity (30–60% one repetition maximum [1RM]) resistance training with slow movement and tonic force generation (LST protocol: 3-s eccentric, 3-s concentric and 1-s isometric actions with no rest between repetitions) caused significant increases in muscle size and strength in untrained young men16,17 and the elderly.18,19 It has been thought that a long total contraction time and/or restriction of muscular blood flow during the LST protocol could be an important factor for inducing muscle hypertrophy.16–19 Non-instrumental resistance training using bodyweight, which is versatile, might enhance the effect of muscle hypertrophy and strength gain in older adults when the LST method is applied – slow movement and sustained contractile force. In fact, a resistance training program using bodyweight and a rubber tube with multiple sets carried out with slow movements was reported to cause muscle hypertrophy in elderly persons.20 However, it is unknown whether the hypertrophic effect found in that study was induced by the slow movement protocol, because the study did not compare it with any other exercise movement. In addition, a program with multiple sets consisting of several items of exercise might not be suitable for elderly people to carry out habitually in daily life. Conversely, the LST protocol has an unfavorable effect on dynamic sports movements.21 Thus, this type of exercise might be ineffective for improving motor function in the activities of daily life of the elderly, such as walking and climbing stairs. For comprehensive improvement of physical function, the LST protocol should be combined with exercises that specialize in improving the nervous system, such as plyometric exercise, which improves muscle power and physical performance.22–24 A light plyometric exercise would be suitable for elderly adults, because there is a large impact in switching from eccentric to concentric contraction during plyometric exercise. The aim of the present study was to investigate the effects of a 16-week intervention program consisting of single-set resistance exercise using the participant’s own bodyweight with the slow movement protocol and light plyometric exercise in regard to muscle size and physical function in elderly participants. We also examined the difference in training effects between resistance exercise movements.
Methods Participants A total of 39 older adults (age 60–77 years) who were active, but not engaged in regular resistance exercise, were recruited. They volunteered as participants after a medical screening. None of them had coronary risk factors, symptoms of cardiovascular disease, definitive 2
|
osteoporosis with the associated risk for compression fracture, uncontrollable hypertension or any other medical problems that might affect the results of the study. The details of participant recruitment are described in the Supporting information. All participants were fully informed about the experimental procedures and their purpose. They gave written informed consent before the study began. The study was approved by the local ethics committee. Participants were subsequently divided into two groups in random order, but balanced to match physical parameters.
Exercise protocol The exercise program consisted of five resistance exercises (squat, split squat, push up, back extension, knee to chest) and four light plyometric exercises (wall push-up, chair standing exercise, getting up exercise, wide step walking) with a single set for each exercise. The rest period between resistance exercise items was 60 s, and that between plyometric exercise items was 30 s. It took approximately 20–30 min to complete the program. Details of the exercise are shown in Table 1. All exercises were carried out using bodyweight as the load. The participants carried out the resistance exercise and then the light plyometric exercise, with a 2-min rest period. Participants were assigned to one of the two experimental groups. One group (n = 20) carried out resistance exercise with slow movement and tonic force generation (3-s concentric, 3-s eccentric and 1-s isometric actions with no rest between each repetition: ST group). The other group (n = 19) carried out the same exercises, but at normal speed (1-s eccentric and 1-s concentric actions with 1-s rest between each repetition: NOR group). Participants in both groups repeated their movements at a constant speed and frequency with the aid of a metronome during the class-style sessions. The number of repetitions of the resistance exercises was increased progressively, and the intensity of exercise could be adjusted by changing exercise form (Table 1). All participants in both groups carried out the same light plyometric exercise program. The number of repetitions of the light plyometric exercises was fixed (Table 1). The exercise program was carried out three times a week (once at a senior citizen center and twice at home) for 16 weeks. A single licensed supervisor instructed each class-style session at the senior citizen center. At home, the participants carried out the intervention program while watching a training video.
Measurement of body composition Lean soft-tissue mass (LSTM; body mass minus bone mass minus fat mass) and fat mass were determined for © 2015 Japan Geriatrics Society
Exercise training using bodyweight in elderly
Table 1 Details of the exercises in the intervention program Exercises Resistance exercises Squats
Split squats
Push-ups
Back extension
Knee to chest
Light plyometric exercises Wall push-ups
Standing up from chair
Standing up from floor
Wide step walking
Instructions
Repetitions 1–8 weeks
9–12 weeks
13–16 weeks
In a shoulder-width stance, bend the knees and hips like sitting in a chair until the thighs become parallel to the floor. Do not move the knees forward beyond the toes during exercise. In a staggered stance, shift the body weight slightly to the front leg and lower the body until the back knee almost touches the floor. Do not move the knees forward beyond the toes during exercise. With the knees on the floor, place the hands on the floor at about 1.5 shoulder-widths, and bend the elbows until the chest almost touches the floor. Sit in a chair, tilt the body forward with the legs separated, and repeatedly extend and flex the spine (upper body) while keeping the epigastric fossa at the center of the movements. Sit on the floor with the knees extended, and pull the knees to the chest.
10
13
15
5
8
10
10
13
15
10
13
15
10
13
15
Stand about 30 cm away from the wall, hold the hands about 1.5 shoulder-widths apart, fall against the wall and bounce back to the upright position. Sit on a chair, stretch backward lightly, and stand up from a chair using the momentum of the forward movement of the upper body. Lie in the supine position with the knees flexed. Raise the buttocks and stand up using the momentum of vigorous dropping of the buttocks. Walk by using the momentum of slightly lowering the hips and leaning the upper body forward in each step.
5
5
5
20 steps
The intensity of resistance exercise could be adjusted by changing the exercise form as follows: the range of motion in the squat and split squat, the position of the knees in the push-up, the position of the arms (on the knees, with arms crossed over the chest, on the head) in the back extension, the angle of the knee joint in the knee-to-chest.
© 2015 Japan Geriatrics Society
|
3
Y Watanabe et al.
Table 2 Anatomical landmarks for measuring the muscle thickness of each muscle Measurement sites
Anatomical landmarks
Chest
At a distance 5 cm lateral to the right clavicular head On the anterior and posterior surface, 60% distal between the lateral epicondyle of the humerus and the acromial process of the scapula At a distance 2–3 cm to the right of the umbilicus At a distance of 5 cm, directly below the inferior angle of the scapula On the anterior and posterior surface, midway between the lateral condyle of the femur and the greater trochanter
Anterior and posterior upper arm
Abdomen Subscapula
Anterior and posterior thigh
the whole body using DXA (Hologic QDR-4500A scanner; Hologic, Newark, DE, USA) before and after the 16-week intervention period, as previously described.17 The post-intervention measurement was made 3–5 days after the final exercise at home.
Measurement of muscle thickness The muscle thicknesses (MT) at seven sites from the anterior and posterior surfaces of the body were measured by B-mode ultrasonography imaging, in which the experimenter was not aware of group allocation, according to the standard method described by Abe et al.25 The sites evaluated were the chest, anterior and posterior upper arm, abdomen, subscapula, and anterior and posterior thigh. The seven anatomical landmarks for the sites are shown in Table 2. Muscle thickness was measured before and after the 16-week intervention. The measurements were made while the participants stood upright. Transverse images were obtained using a real-time linear electronic scanner with a 7.5-MHz scanning head (SSD-500; Aloka, Tokyo, Japan). The scanning head was pretreated with watersoluble transmission gel that provided acoustic contact without compressing the skin surface. The measurements were repeated twice for each portion, and the mean of the two values was used for analysis. The 4
|
intraclass correlation coefficient and the mean coefficient of variance for the repeated measurements were 0.998 and 1.6%, respectively.
Measurement of physical function Strengths of the upper and lower limb and physical function were measured before and after the intervention. The experimenter was not aware of the group allocation. The isometric/isokinetic strengths of knee-extension (KE) and shoulder horizontal flexion (SHF) were measured using an isokinetic dynamometer (Cybex RZ-450; Cybex, Medway, MA, USA). KE was assessed in the seated position and SHF was assessed with the participant lying down. The isometric peak torques were measured at a knee angle of 60° KE (0° representing full extension) and at a shoulder angle of 15° SHF (0° representing shoulder abduction of 90°). The isokinetic torque was measured at angular velocities of 90°/s. The range of angular movement of the joints was limited between 0° and 110° of the anatomical knee angle in KE and 0° and 100° of the anatomical shoulder angle in SHF. Peak torque was measured regardless of where it developed within the range of movement. For both isometric and isokinetic measurements, after participants were familiarized with the test procedure, two trials at maximum effort were made with a 2-min recovery period. The higher value obtained was used for analysis. The following five physical parameters were measured: walking speed, five-times chair stand time (5CS), one-leg standing time, two-step value and maximum leg extensor power. The two-step value was defined as the value obtained by dividing the height of the maximum two-step stride.26 Table 3 provides further details about the tests carried out.
Statistical analyses All values obtained are expressed as means ± SD. The adherence to the weekly session is reported as median and interquartile range. An intention-to-treat analysis was applied to all measurements. Thus, all participants assigned to each group were analyzed without considering attendance rate or the exercise situation at home. All variables were analyzed with a repeated two-way analysis of variance (group × time) with a Bonferroni post-hoc procedure. For all statistical tests, P < 0.05 was considered significant.
Results The flow of the present study is shown in the Figure S1. The adherence to the weekly class-style session were 95.0% (90.0–95.0%) for the ST group and 89.5% © 2015 Japan Geriatrics Society
Exercise training using bodyweight in elderly
Table 3 Detail of the physical function tests Physical function test
Detail of measurements
Walking speed
Participants walked along a straight 11-m walkway on a flat floor. The time taken to walk 5 m, from the 3-m to the 8-m line, was measured by a time counter (3421000YW; Yagami, Nagoya, Japan). Walking tests at usual and maximum speeds were repeated twice, and the mean values were used for analyses. Walking speed (m/s) was calculated from the walking time. Participants were instructed to stand up and sit down as quickly as possible on a firm, padded, armless chair with a seat that was 0.43 m high from the ground. They were instructed to fold their arms across their chest during the test. The five times sit-to-stand time was recorded. Participants were instructed to stand on one leg as long as possible with eyes open, placing the hands on the hip. The criteria to stop the test were when 1) participant’s foot touched the floor or the standing leg, 2) the foot moved on the floor, 3) the hands were off from the start position. Participants were instructed to walk two steps as far as possible without jumping, and then the two-step stride was measured. The two-step value was obtained by the maximum two-step stride dividing by the height. Maximum leg extensor power was determined by an isokinetic dynamometer (Aneropress 3500; Combi, Tokyo, Japan). Participants were instructed to sit on the seat of the instrument and press their feet forward on the plate as fast as possible until the legs were fully extended. The body mass of each was applied as resistance. The best score of five trials was used for this analysis.
Five-times chair stand time
One-leg standing time
Two-step value
Maximum leg extensor power
(84.2–94.7%) for the NOR group. The median exercise frequency in a week was 2.91 times in the ST group and 2.88 times in the NOR group (for details, see Supporting information). The data were confirmed by the training logs that had been maintained by the participants. There were no orthopedic injuries associated with the exercise program throughout the intervention period. The changes in body composition and the MT obtained from seven measurement sites before and after the intervention are summarized in Table 4. There were no significant differences between groups for any of the parameters before the intervention. Although there were no significant changes in body composition variables after the intervention period in either group, there was a trend for the LSTM to increase (time effect, P = 0.073) and the fat percentage to decrease (time effect, P = 0.062) after the intervention in both groups. There were no significant differences between groups in any of the parameters. In addition, no significant changes in the MT after the experimental period were found. Table 5 shows changes in physical function. Before intervention, there were no significant differences between groups for any of the parameters. Significant time effects were observed for all strengths of the upper and lower limbs (time effect, P < 0.05; for details see Table 5), the two-step value (time effect, P < 0.001), and maximum leg extensor power (time effect, P = 0.032) in both groups. There was also a trend towards improve© 2015 Japan Geriatrics Society
ment in the 5CS test (time effect, P = 0.068) in both groups. There were no significant changes in the usual 5-m walking speed or the one-leg standing test in either group. A trend toward a decrease in the maximum 5-m walking speed (time effect, P = 0.065) was observed in both groups. When relative changes were compared between groups, there were no significant differences in any of parameters.
Discussion The 16-week intervention program using only the participant’s own bodyweight was effective for improving physical function and achieving strength gain in older individuals even with a single set of each exercise. A trend to increase the LSTM was also observed, although there was no significant muscle hypertrophic effect. Indeed, there were no significant differences in any of the parameters between the ST and NOR training protocols. A previous study showed that LST training with 50% 1RM caused a 6.5% increase in front thigh MT and a 6.1% increase in back thigh MT in active older individuals.19 In addition, a recent study has reported that even 30% 1RM LST caused a 5.0% increase in the cross-sectional area of quadriceps muscle in active elderly participants.18 These studies suggest that the slow movement method is effective for enhancing muscle hypertrophy and strength gain in older people. |
5
Y Watanabe et al.
Table 4 Body composition and muscle thickness before and after the intervention ST Pre Age (years) Sex (women) Height (cm) Weight (kg) Lean soft-tissue mass (kg) Fat mass (kg) Fat percent (%) Muscle thickness (mm) Chest Anterior upper arm Posterior upper arm Abdomen Subscapula Anterior thigh Posterior thigh Total muscle thickness
66.0 ± 2.9 10 (50.0%) 158.1 ± 7.4 59.5 ± 9.6 43.4 ± 8.3 16.1 ± 4.3 27.1 ± 6.7 20.6 ± 6.1 34.6 ± 5.5 30.1 ± 5.7 9.6 ± 2.7 20.0 ± 3.3 43.9 ± 5.7 59.2 ± 6.8 218.0 ± 26.0
NOR Pre
Post
Post
Time effect
Interaction
59.3 ± 9.4 43.7 ± 8.3 15.7 ± 4.3 26.5 ± 6.7
66.9 ± 4.1 9 (47.4%) 157.9 ± 7.6 59.4 ± 10.5 43.9 ± 8.9 15.6 ± 4.6 26.3 ± 6.8
59.7 ± 10.5 44.1 ± 8.8 15.6 ± 4.8 26.2 ± 6.8
0.728 0.073 0.165 0.062
0.176 0.811 0.061 0.112
20.7 ± 3.7 34.6 ± 5.5 30.0 ± 5.4 10.0 ± 3.2 20.7 ± 3.3 42.8 ± 5.6 59.3 ± 6.5 218.0 ± 25.5
20.1 ± 4.5 34.6 ± 4.7 29.4 ± 6.3 10.0 ± 2.3 18.2 ± 4.8 42.9 ± 6.7 57.7 ± 8.6 212.8 ± 29.1
20.4 ± 3.9 33.8 ± 4.7 29.2 ± 6.2 10.0 ± 2.4 18.8 ± 4.7 42.3 ± 6.9 58.7 ± 8.1 213.1 ± 29.5
0.702 0.159 0.717 0.335 0.069 0.071 0.178 0.896
0.811 0.124 0.993 0.287 0.819 0.620 0.235 0.893
Time effect, change from before intervention in both groups; Interaction, difference between groups. NOR, resistance training at normal speed; Post, after intervention; Pre, before intervention; ST, resistance training with slow movement and tonic force generation.
Table 5 Physical function before and after the intervention ST Pre Isometric torque (N·m) Knee extension Shoulder horizontal flexion Isokinetic torque (N·m) Knee extension Shoulder horizontal flexion Usual walking speed (m/s) Maximum walking speed (m/s) Five chair stand time (s) One-leg standing time (s) Two-step value Maximal leg extensor power (w/kg)
Post
NOR Pre
Post
Time effect
Interaction
123.5 ± 46.0 35.3 ± 16.1
137.9 ± 47.7 42.8 ± 18.7
121.9 ± 45.8 35.2 ± 15.9
135.1 ± 46.8 44.9 ± 19.3
Geriatr Gerontol Int 2015
ORIGINAL ARTICLE: EPIDEMIOLOGY, CLINICAL PRACTICE AND HEALTH
Effect of resistance training using bodyweight in the elderly: Comparison of resistance exercise movement between slow and normal speed movement Yuya Watanabe,1,2 Michiya Tanimoto,3 Naoko Oba,4 Kiyoshi Sanada,5 Motohiko Miyachi6 and Naokata Ishii4 1
Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 2Faculty of Bioenvironmental Science, Kyotogakuen University, Kyoto, 3Faculty of Biology-Oriented Science and Technology, Kinki University, Wakayama, 4Department of Life Sciences, The University of Tokyo, Tokyo, 5College of Sport and Health Sciences, Ritsumeikan University, Shiga, and 6Divison of Health Promotion and Exercise, National Institutes of Health and Nutrition, Tokyo, Japan
Aim: The present study investigated whether a slow movement protocol can be applied to resistance training using bodyweight. In addition, the intervention program combined plyometric exercise with resistance exercise to improve physical function overall. Methods: A total of 39 active elderly adults participated in a 16-week intervention. The program consisted of five resistance exercises and four plyometric exercises using their own bodyweight with a single set for each exercise. Participants were assigned to one of two experimental groups. One group carried out resistance exercise with slow movement and tonic force generation (3-s concentric, 3-s eccentric and 1-s isometric actions with no rest between each repetition). The other group as a movement comparison followed the same regimen, but at normal speed (1-s eccentric and 1-s concentric actions with 1-s rest between each repetition). Muscle size, strength and physical function were measured before and after the intervention period. Results: After the intervention, strengths of upper and lower limbs, and maximum leg extensor power were significantly improved in both groups. Muscle size did not change in either group. There were no significant differences in any of the parameters between groups. Conclusions: The intervention program using only own bodyweight that comprised resistance exercise with slow movement and plyometric exercise can improve physical function in the elderly, even with single sets for each exercise. However, there was no enhanced muscle hypertrophic effect. Further attempts, such as increasing performing multiple sets, would be required to induce muscle hypertrophy. Geriatr Gerontol Int 2015; ••: ••–••. Keywords: low-intensity resistance training, sarcopenia, strength training.
Introduction Sarcopenia, the aging-related loss of muscle mass and/or strength,1–3 is associated with the risk of falls and fractures, physical disability, loss of independence, lifestyle-related diseases, and mortality.4–10 Thus, skelAccepted for publication 13 October 2014. Correspondence: Dr Yuya Watanabe PhD, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamikyo-ku, Kyoto 602-8566, Japan. Email: [email protected] At the time of intervention, Watanabe was at the Department of Life Sciences, The University of Tokyo. Tanimoto was at the Division of Health Promotion and Exercise, National Institutes of Health and Nutrition.
© 2015 Japan Geriatrics Society
etal muscle mass and strength are important factors for maintaining independence and quality of life in older individuals. To increase muscle mass and strength in older people, resistance training has been considered the most effective intervention.11,12 Although high-intensity resistance training has been used extensively to increase muscle mass and strength,13 exercise with large mechanical stress might be associated with a risk of orthopedic injury14 and markedly increased systolic blood pressure.15 In addition, these resistance training programs require special equipment, exercise facilities and supervised instruction in most cases. Therefore, it is difficult to carry out normal high-intensity resistance training for many elderly individuals, although this program is highly effective for preventing sarcopenia. doi: 10.1111/ggi.12427
|
1
Y Watanabe et al.
Recent studies have reported that relatively lowintensity (30–60% one repetition maximum [1RM]) resistance training with slow movement and tonic force generation (LST protocol: 3-s eccentric, 3-s concentric and 1-s isometric actions with no rest between repetitions) caused significant increases in muscle size and strength in untrained young men16,17 and the elderly.18,19 It has been thought that a long total contraction time and/or restriction of muscular blood flow during the LST protocol could be an important factor for inducing muscle hypertrophy.16–19 Non-instrumental resistance training using bodyweight, which is versatile, might enhance the effect of muscle hypertrophy and strength gain in older adults when the LST method is applied – slow movement and sustained contractile force. In fact, a resistance training program using bodyweight and a rubber tube with multiple sets carried out with slow movements was reported to cause muscle hypertrophy in elderly persons.20 However, it is unknown whether the hypertrophic effect found in that study was induced by the slow movement protocol, because the study did not compare it with any other exercise movement. In addition, a program with multiple sets consisting of several items of exercise might not be suitable for elderly people to carry out habitually in daily life. Conversely, the LST protocol has an unfavorable effect on dynamic sports movements.21 Thus, this type of exercise might be ineffective for improving motor function in the activities of daily life of the elderly, such as walking and climbing stairs. For comprehensive improvement of physical function, the LST protocol should be combined with exercises that specialize in improving the nervous system, such as plyometric exercise, which improves muscle power and physical performance.22–24 A light plyometric exercise would be suitable for elderly adults, because there is a large impact in switching from eccentric to concentric contraction during plyometric exercise. The aim of the present study was to investigate the effects of a 16-week intervention program consisting of single-set resistance exercise using the participant’s own bodyweight with the slow movement protocol and light plyometric exercise in regard to muscle size and physical function in elderly participants. We also examined the difference in training effects between resistance exercise movements.
Methods Participants A total of 39 older adults (age 60–77 years) who were active, but not engaged in regular resistance exercise, were recruited. They volunteered as participants after a medical screening. None of them had coronary risk factors, symptoms of cardiovascular disease, definitive 2
|
osteoporosis with the associated risk for compression fracture, uncontrollable hypertension or any other medical problems that might affect the results of the study. The details of participant recruitment are described in the Supporting information. All participants were fully informed about the experimental procedures and their purpose. They gave written informed consent before the study began. The study was approved by the local ethics committee. Participants were subsequently divided into two groups in random order, but balanced to match physical parameters.
Exercise protocol The exercise program consisted of five resistance exercises (squat, split squat, push up, back extension, knee to chest) and four light plyometric exercises (wall push-up, chair standing exercise, getting up exercise, wide step walking) with a single set for each exercise. The rest period between resistance exercise items was 60 s, and that between plyometric exercise items was 30 s. It took approximately 20–30 min to complete the program. Details of the exercise are shown in Table 1. All exercises were carried out using bodyweight as the load. The participants carried out the resistance exercise and then the light plyometric exercise, with a 2-min rest period. Participants were assigned to one of the two experimental groups. One group (n = 20) carried out resistance exercise with slow movement and tonic force generation (3-s concentric, 3-s eccentric and 1-s isometric actions with no rest between each repetition: ST group). The other group (n = 19) carried out the same exercises, but at normal speed (1-s eccentric and 1-s concentric actions with 1-s rest between each repetition: NOR group). Participants in both groups repeated their movements at a constant speed and frequency with the aid of a metronome during the class-style sessions. The number of repetitions of the resistance exercises was increased progressively, and the intensity of exercise could be adjusted by changing exercise form (Table 1). All participants in both groups carried out the same light plyometric exercise program. The number of repetitions of the light plyometric exercises was fixed (Table 1). The exercise program was carried out three times a week (once at a senior citizen center and twice at home) for 16 weeks. A single licensed supervisor instructed each class-style session at the senior citizen center. At home, the participants carried out the intervention program while watching a training video.
Measurement of body composition Lean soft-tissue mass (LSTM; body mass minus bone mass minus fat mass) and fat mass were determined for © 2015 Japan Geriatrics Society
Exercise training using bodyweight in elderly
Table 1 Details of the exercises in the intervention program Exercises Resistance exercises Squats
Split squats
Push-ups
Back extension
Knee to chest
Light plyometric exercises Wall push-ups
Standing up from chair
Standing up from floor
Wide step walking
Instructions
Repetitions 1–8 weeks
9–12 weeks
13–16 weeks
In a shoulder-width stance, bend the knees and hips like sitting in a chair until the thighs become parallel to the floor. Do not move the knees forward beyond the toes during exercise. In a staggered stance, shift the body weight slightly to the front leg and lower the body until the back knee almost touches the floor. Do not move the knees forward beyond the toes during exercise. With the knees on the floor, place the hands on the floor at about 1.5 shoulder-widths, and bend the elbows until the chest almost touches the floor. Sit in a chair, tilt the body forward with the legs separated, and repeatedly extend and flex the spine (upper body) while keeping the epigastric fossa at the center of the movements. Sit on the floor with the knees extended, and pull the knees to the chest.
10
13
15
5
8
10
10
13
15
10
13
15
10
13
15
Stand about 30 cm away from the wall, hold the hands about 1.5 shoulder-widths apart, fall against the wall and bounce back to the upright position. Sit on a chair, stretch backward lightly, and stand up from a chair using the momentum of the forward movement of the upper body. Lie in the supine position with the knees flexed. Raise the buttocks and stand up using the momentum of vigorous dropping of the buttocks. Walk by using the momentum of slightly lowering the hips and leaning the upper body forward in each step.
5
5
5
20 steps
The intensity of resistance exercise could be adjusted by changing the exercise form as follows: the range of motion in the squat and split squat, the position of the knees in the push-up, the position of the arms (on the knees, with arms crossed over the chest, on the head) in the back extension, the angle of the knee joint in the knee-to-chest.
© 2015 Japan Geriatrics Society
|
3
Y Watanabe et al.
Table 2 Anatomical landmarks for measuring the muscle thickness of each muscle Measurement sites
Anatomical landmarks
Chest
At a distance 5 cm lateral to the right clavicular head On the anterior and posterior surface, 60% distal between the lateral epicondyle of the humerus and the acromial process of the scapula At a distance 2–3 cm to the right of the umbilicus At a distance of 5 cm, directly below the inferior angle of the scapula On the anterior and posterior surface, midway between the lateral condyle of the femur and the greater trochanter
Anterior and posterior upper arm
Abdomen Subscapula
Anterior and posterior thigh
the whole body using DXA (Hologic QDR-4500A scanner; Hologic, Newark, DE, USA) before and after the 16-week intervention period, as previously described.17 The post-intervention measurement was made 3–5 days after the final exercise at home.
Measurement of muscle thickness The muscle thicknesses (MT) at seven sites from the anterior and posterior surfaces of the body were measured by B-mode ultrasonography imaging, in which the experimenter was not aware of group allocation, according to the standard method described by Abe et al.25 The sites evaluated were the chest, anterior and posterior upper arm, abdomen, subscapula, and anterior and posterior thigh. The seven anatomical landmarks for the sites are shown in Table 2. Muscle thickness was measured before and after the 16-week intervention. The measurements were made while the participants stood upright. Transverse images were obtained using a real-time linear electronic scanner with a 7.5-MHz scanning head (SSD-500; Aloka, Tokyo, Japan). The scanning head was pretreated with watersoluble transmission gel that provided acoustic contact without compressing the skin surface. The measurements were repeated twice for each portion, and the mean of the two values was used for analysis. The 4
|
intraclass correlation coefficient and the mean coefficient of variance for the repeated measurements were 0.998 and 1.6%, respectively.
Measurement of physical function Strengths of the upper and lower limb and physical function were measured before and after the intervention. The experimenter was not aware of the group allocation. The isometric/isokinetic strengths of knee-extension (KE) and shoulder horizontal flexion (SHF) were measured using an isokinetic dynamometer (Cybex RZ-450; Cybex, Medway, MA, USA). KE was assessed in the seated position and SHF was assessed with the participant lying down. The isometric peak torques were measured at a knee angle of 60° KE (0° representing full extension) and at a shoulder angle of 15° SHF (0° representing shoulder abduction of 90°). The isokinetic torque was measured at angular velocities of 90°/s. The range of angular movement of the joints was limited between 0° and 110° of the anatomical knee angle in KE and 0° and 100° of the anatomical shoulder angle in SHF. Peak torque was measured regardless of where it developed within the range of movement. For both isometric and isokinetic measurements, after participants were familiarized with the test procedure, two trials at maximum effort were made with a 2-min recovery period. The higher value obtained was used for analysis. The following five physical parameters were measured: walking speed, five-times chair stand time (5CS), one-leg standing time, two-step value and maximum leg extensor power. The two-step value was defined as the value obtained by dividing the height of the maximum two-step stride.26 Table 3 provides further details about the tests carried out.
Statistical analyses All values obtained are expressed as means ± SD. The adherence to the weekly session is reported as median and interquartile range. An intention-to-treat analysis was applied to all measurements. Thus, all participants assigned to each group were analyzed without considering attendance rate or the exercise situation at home. All variables were analyzed with a repeated two-way analysis of variance (group × time) with a Bonferroni post-hoc procedure. For all statistical tests, P < 0.05 was considered significant.
Results The flow of the present study is shown in the Figure S1. The adherence to the weekly class-style session were 95.0% (90.0–95.0%) for the ST group and 89.5% © 2015 Japan Geriatrics Society
Exercise training using bodyweight in elderly
Table 3 Detail of the physical function tests Physical function test
Detail of measurements
Walking speed
Participants walked along a straight 11-m walkway on a flat floor. The time taken to walk 5 m, from the 3-m to the 8-m line, was measured by a time counter (3421000YW; Yagami, Nagoya, Japan). Walking tests at usual and maximum speeds were repeated twice, and the mean values were used for analyses. Walking speed (m/s) was calculated from the walking time. Participants were instructed to stand up and sit down as quickly as possible on a firm, padded, armless chair with a seat that was 0.43 m high from the ground. They were instructed to fold their arms across their chest during the test. The five times sit-to-stand time was recorded. Participants were instructed to stand on one leg as long as possible with eyes open, placing the hands on the hip. The criteria to stop the test were when 1) participant’s foot touched the floor or the standing leg, 2) the foot moved on the floor, 3) the hands were off from the start position. Participants were instructed to walk two steps as far as possible without jumping, and then the two-step stride was measured. The two-step value was obtained by the maximum two-step stride dividing by the height. Maximum leg extensor power was determined by an isokinetic dynamometer (Aneropress 3500; Combi, Tokyo, Japan). Participants were instructed to sit on the seat of the instrument and press their feet forward on the plate as fast as possible until the legs were fully extended. The body mass of each was applied as resistance. The best score of five trials was used for this analysis.
Five-times chair stand time
One-leg standing time
Two-step value
Maximum leg extensor power
(84.2–94.7%) for the NOR group. The median exercise frequency in a week was 2.91 times in the ST group and 2.88 times in the NOR group (for details, see Supporting information). The data were confirmed by the training logs that had been maintained by the participants. There were no orthopedic injuries associated with the exercise program throughout the intervention period. The changes in body composition and the MT obtained from seven measurement sites before and after the intervention are summarized in Table 4. There were no significant differences between groups for any of the parameters before the intervention. Although there were no significant changes in body composition variables after the intervention period in either group, there was a trend for the LSTM to increase (time effect, P = 0.073) and the fat percentage to decrease (time effect, P = 0.062) after the intervention in both groups. There were no significant differences between groups in any of the parameters. In addition, no significant changes in the MT after the experimental period were found. Table 5 shows changes in physical function. Before intervention, there were no significant differences between groups for any of the parameters. Significant time effects were observed for all strengths of the upper and lower limbs (time effect, P < 0.05; for details see Table 5), the two-step value (time effect, P < 0.001), and maximum leg extensor power (time effect, P = 0.032) in both groups. There was also a trend towards improve© 2015 Japan Geriatrics Society
ment in the 5CS test (time effect, P = 0.068) in both groups. There were no significant changes in the usual 5-m walking speed or the one-leg standing test in either group. A trend toward a decrease in the maximum 5-m walking speed (time effect, P = 0.065) was observed in both groups. When relative changes were compared between groups, there were no significant differences in any of parameters.
Discussion The 16-week intervention program using only the participant’s own bodyweight was effective for improving physical function and achieving strength gain in older individuals even with a single set of each exercise. A trend to increase the LSTM was also observed, although there was no significant muscle hypertrophic effect. Indeed, there were no significant differences in any of the parameters between the ST and NOR training protocols. A previous study showed that LST training with 50% 1RM caused a 6.5% increase in front thigh MT and a 6.1% increase in back thigh MT in active older individuals.19 In addition, a recent study has reported that even 30% 1RM LST caused a 5.0% increase in the cross-sectional area of quadriceps muscle in active elderly participants.18 These studies suggest that the slow movement method is effective for enhancing muscle hypertrophy and strength gain in older people. |
5
Y Watanabe et al.
Table 4 Body composition and muscle thickness before and after the intervention ST Pre Age (years) Sex (women) Height (cm) Weight (kg) Lean soft-tissue mass (kg) Fat mass (kg) Fat percent (%) Muscle thickness (mm) Chest Anterior upper arm Posterior upper arm Abdomen Subscapula Anterior thigh Posterior thigh Total muscle thickness
66.0 ± 2.9 10 (50.0%) 158.1 ± 7.4 59.5 ± 9.6 43.4 ± 8.3 16.1 ± 4.3 27.1 ± 6.7 20.6 ± 6.1 34.6 ± 5.5 30.1 ± 5.7 9.6 ± 2.7 20.0 ± 3.3 43.9 ± 5.7 59.2 ± 6.8 218.0 ± 26.0
NOR Pre
Post
Post
Time effect
Interaction
59.3 ± 9.4 43.7 ± 8.3 15.7 ± 4.3 26.5 ± 6.7
66.9 ± 4.1 9 (47.4%) 157.9 ± 7.6 59.4 ± 10.5 43.9 ± 8.9 15.6 ± 4.6 26.3 ± 6.8
59.7 ± 10.5 44.1 ± 8.8 15.6 ± 4.8 26.2 ± 6.8
0.728 0.073 0.165 0.062
0.176 0.811 0.061 0.112
20.7 ± 3.7 34.6 ± 5.5 30.0 ± 5.4 10.0 ± 3.2 20.7 ± 3.3 42.8 ± 5.6 59.3 ± 6.5 218.0 ± 25.5
20.1 ± 4.5 34.6 ± 4.7 29.4 ± 6.3 10.0 ± 2.3 18.2 ± 4.8 42.9 ± 6.7 57.7 ± 8.6 212.8 ± 29.1
20.4 ± 3.9 33.8 ± 4.7 29.2 ± 6.2 10.0 ± 2.4 18.8 ± 4.7 42.3 ± 6.9 58.7 ± 8.1 213.1 ± 29.5
0.702 0.159 0.717 0.335 0.069 0.071 0.178 0.896
0.811 0.124 0.993 0.287 0.819 0.620 0.235 0.893
Time effect, change from before intervention in both groups; Interaction, difference between groups. NOR, resistance training at normal speed; Post, after intervention; Pre, before intervention; ST, resistance training with slow movement and tonic force generation.
Table 5 Physical function before and after the intervention ST Pre Isometric torque (N·m) Knee extension Shoulder horizontal flexion Isokinetic torque (N·m) Knee extension Shoulder horizontal flexion Usual walking speed (m/s) Maximum walking speed (m/s) Five chair stand time (s) One-leg standing time (s) Two-step value Maximal leg extensor power (w/kg)
Post
NOR Pre
Post
Time effect
Interaction
123.5 ± 46.0 35.3 ± 16.1
137.9 ± 47.7 42.8 ± 18.7
121.9 ± 45.8 35.2 ± 15.9
135.1 ± 46.8 44.9 ± 19.3
