Background
Older persons often exhibit impairment in balance, muscle strength, cognition, and physical activity which can limit normal functions [
1] and may lead to fall [
2]. The use of several different exercises such as aerobic exercise, balance exercise, resistance exercise, exergames, and complex sports like martial arts can enhance physical function and cognition [
3‐
17]. However, not all exercises are suitable to every older persons.
Physical exercise (PE) is conventional exercise such as aerobic, resistance, flexibility, and balance exercises that are often recommended for older persons [
18]. PE can improve not only balance and physical function [
3‐
7], but also cognition [
8‐
14] in older persons. Aerobic exercise [
19‐
22] and resistance exercise [
11,
23], both separately and in combination [
9,
20], can improve cognition in older persons. Additionally, aerobic and balance exercises link to executive function, a component of cognition [
24]. Likewise, coordination exercise can improve cognition in older persons [
25‐
27], appearing to involve in perceptual speed and visual-spatial network [
25,
26]. Aerobic and coordination exercises are concluded to be more beneficial to cognitive process than stretching and balance exercises [
13,
14]. One of the best ways to improve cognition with PE is to combine several kinds of PE [
14]. Although PE is a standard exercise and is important to cognition in older persons, the exercise may carry risk for them due to age-related physiological deteriorations such as osteoporosis and sarcopenia [
28‐
30]. Vertebral fractures in performing yoga spinal flexion positions [
31], and shoulder injuries during progressive resistance training [
32] were reported in older persons. These conditions make PE an inappropriate choice for many older persons that require an exercise program. Moreover, review studies propose less effective in cognitive improvement in pure PE alone than combining PE with cognitive training [
12‐
14]. The multi-domain training is therefore suggested for older persons [
12].
Virtual reality-based exercise (VRE) involves both physical and mental exercises and requires players to respond to sensory input to perform various tasks in technological stimulated scenarios [
17]. VRE, such as playing virtual reality games, could be an alternative to PE for exercise therapy since VRE improves motor, and cognitive abilities [
16,
17,
33‐
36] as well as muscle strength and balance in older persons [
15,
16]. However, meta-analytic studies in action video game training [
34,
35] and computerized cognitive training [
36] demonstrate small benefit in both overall cognition and specific cognitive domains in older persons. Older persons benefit less from action video game training than healthy young adults in cognition [
34] and show ineffective for executive function and verbal memory from computerized cognitive training [
36]. Thus, suggestion of VRE to older persons and its effect on cognition in older persons still need investigations, particularly comparison with PE. Furthermore, some older persons may be unacquainted with VRE technology. This exercise technique may not be suitable for all people.
Brain exercise (BE) is an exercise technique that can improve cognitive function [
37] allowing older persons to better perform basic daily activities [
38]. The BE technique can be either technology based [
39,
40] or utilize traditional games and activities [
41]. Playing brain stimulating video games improves executive function and processing speed [
39,
40], as well as short and long term memory [
40]. In addition, playing board games promotes interest, planning, and memory, as well as reducing depression and anxiety in older persons [
41]. Declines in cognitive abilities lead to difficulty in performing basic activities required for daily living [
42‐
45], and increase the chance of injury inducing falls [
46‐
48] in older persons. Thus, brain exercise promoting cognition [
40] is assumed to influence balance and physical abilities in older persons who cannot use either PE or VRE techniques.
Currently, the benefit of PE, VRE, and BE on different mental and physical parameters remains unclear with evidence describing which exercise is superior for enhancement of physical or cognitive ability lacking. In addition, which of these exercise techniques are preferred by older persons has not been reported. Therefore, the goals of this study were to 1) compare effects of PE, VRE, and BE on balance, muscle strength, cognition, and fall concern in older persons, and 2) determine exercise effort perception and exercise contentment in older persons.
Discussion
The purpose of the present study was to compare the effects of PE, VRE, and BE on balance, muscle strength, cognition, and fall concern, and to determine exercise effort perception and exercise contentment in older persons. PE, VRE, and BE routines were advantageous to balance, muscle strength, cognition, and fall concern in older persons. PE was important for balance and muscle strength, VRE for muscle strength, cognition, and fall concern, and BE for cognition. Older persons perceived exercise effort in PE and VRE. They were satisfied in BE, found both VRE and BE pleasurable, and gained benefit from all exercises.
The present findings demonstrate enhancement in balance, muscle strength, cognition, and fall concern in older persons after PE, VRE, or BE. The BBS and TUG values improved after exercise, demonstrating balance correction. The effect of PE on balance was not surprising as several exercises were directed to improve balance and lower limb muscle strength, for example single leg stance, tandem stance, sit to stand squat, and heel-toes raise. In addition, PE encouraged balance by increasing muscle strength. Participants in the PE group demonstrated decreased 5TSTS performance time and increased left and right HGS. The present finding supports the effect of PE on balance, similar to previous reports [
3,
4,
6,
7].
The VRE in the present study was designed to move upper and lower limbs as well as trunk for balance training. This exercise routine enhanced balance by triggering weight shifting, in addition to improvement in 5TSTS performance and left and right HGS. Moreover, VRE increased MoCA scores which may affect balance since cognition and postural balance are associated in older persons [
71‐
73]. The present findings agrees with previous reports [
15,
16] on the effect of VRE on balance.
In the study the BE also improved balance. The BE routine promotes cognition that may be associated with balance and muscle strength improvement. Cognitive function is related to balance performance [
74] and muscle strength [
75,
76] which was evident in patients with cognitive impairment and Alzheimer disease. In the present study, the average MMSE scores of all participants was around 25 with the range of 24–28 indicating normal cognition [
50]. However, their average MoCA scores before exercise was about 20 with the range of 18–25, showing cognitive impairment [
69]. Participants in the BE group had cognitive impairment presented by the average MoCA score at pre-test of 20.8 with the range of 18–24. Therefore, BE may improve balance through enhanced cognitive function.
Although PE did not change MoCA scores, it did improve TUG-cog performance. This may be from greater improvement in physical function, 5TSTS, BBS, and TUG, than cognition alone. The effect of PE on cognition may require prolonged therapy since PE increases cerebral blood flow [
77], and reduces neuroinflammation and other risk factors of cognition decline [
78]. Previous studies have shown memory and cognitive improvement using 12-week balance training in healthy adults [
79] and 6-month multi-exercise in older persons with mild cognitive impairment [
80]. In the present study, 8 weeks of PE may be insufficient to enhance cognition. In contrast, VRE and BE may directly improve cognition, producing the improved TUG-cog performance.
In the present study, recovery of balance and muscle strength may promote confidence in doing tasks leading to decreased FES-I. The VRE routine appeared to be the best training for improvement of fall concern. A possible explanation is that VRE requires both physical and cognitive practice, whereas PE involves mainly physical and BE engages primarily in cognition. Among the three exercises, the present study indicates that PE improved balance with increased muscle strength, VRE enhanced balance via raised muscle strength and cognition, whereas BE improved balance with recovered cognition.
Older persons perceived exercise exertion in all sessions of PE and VRE, whereas they experienced effort in only first 4 sessions of BE. They also reported greater action levels in PE and VRE than BE. The PE and VRE routines involved the use of several large muscles, whereas BE engaged brain operations and small muscles, particularly of the hands. The score of Borg CR-10 after PE and VRE was 3–4, demonstrating moderate exercise effort, whereas that of BE was less than 1, corresponding to very light exertion. The greater score in PE and VRE could be explained by the need for using numerous muscle groups, resulting in increased exertion [
81].
Although older persons involved in either exercise or non-exercise regimens demonstrated almost similar level of satisfaction in their tasks, those in BE group showed important satisfaction. Among PE, VRE, and BE, older persons derived pleasure from VRE and BE. They considered both exercises to be recreational activities. Furthermore, the BE had the highest rating for satisfaction, pleasure, and benefit of exercise. This might be related to social interaction as participants played these games two players at the time. From the effects of VRE and BE, these exercise routines are suggested to be given regularly to older persons unable to perform PE. Participants in the control group did not receive any intervention and did their daily activities according to the program of homes for the aged where they lived. Therefore, the passive control group might not have motivation compared to the exercise groups receiving different types of training, contacting a physiotherapist, and interacting with technology or persons. Consequently, they were less joyful and perceived less benefit from their programs.
The present study did comparison with a passive control group, however, the causal conclusions about the efficacy of PE, VRE, and BE could be drawn by other important components integrated in research methods [
82,
83]. For example, the study was preregistration, random allocation, and blinding [
82,
83]. There were two measures used in each outcome construct [
82,
83]. Number of sample size was calculated with power analysis 0.8, the number in each group was large enough to observe effects [
82,
83]. Training tasks were not similar to the outcome measures [
84]. Participants in VRE group had never ever experienced with action video games [
83,
84]. Those in BE group had no experience in board games, except one participant had experience in Chinese checker when he was young. In all outcome measures there was no difference between pre- and post-test in the control group, and no baseline difference among PE, VRE, BE, and control groups, presenting the control group being an acceptable control for placebo effect [
84], and an adequate baseline for transfer effects [
85]. Effect size of differences between exercise groups and the control were large in all outcome measures, except 5TSTS in BE and FES-I in PE were medium [
82]. In the present study the effectiveness of PE, VRE, and BE were, therefore, reliable.
Limitations
Participants lived at homes for the aged and had similar activities of daily living, for example washing clothes, cleaning beds and cupboards, praying, watching television, and having tea break in the afternoon. The participants in the study were very homogenous. In addition, brain games were designed to be played by two players. Hence, the present findings and the design of playing brain games may not be directly applicable to older persons living at home. Future study conducted in community-dwelling older persons is suggested to corroborate the present findings.
In the study there were several intervention groups. A task for the control group could not be designed to match to the exercise groups in term of task demands. The inappropriate task may lead the control group to be the inadequate active control condition [
83,
84]. Thus, the control group was the passive control that was arranged in a real-world situation. To provide more powerful evidence for the effectiveness of interventions, particularly training with action video and broad games [
83], future study would consider particular activities of the control group to the treatment group. Moreover, measurement of expectation on each outcome measure between the control and intervention groups is suggested [
84,
85].