Effectiveness of Training Programs in Reducing Falls in Older Adults: Systematic Review in

Background: With ageing, older adults are faced with decreasing strength and balance and increasing risk for falls. A fall followed by fracture is a factor in mortality and decreased quality of life in older people. However, few systematic review studies have analyzed the effects of training programs in reducing falls in older people. Aim: This systematic review study aimed to analyze the effects of physical training programs on the risk of falls in older people. Methods: We used the PRISMA guidelines in conducting the systematic review. The search for eligible studies was performed using four electronic databases (PubMed, BVS Regional Portal, British Library, and Library of Congress). Results: The results showed a decrease in the risk of falling in 21 studies. Only four studies did not show a reduction in the risk of falling after a training program. Conclusion: Combined or multicomponent training programs, as well as isolated strength training, could decrease the risk of falling in older people. Core Tip Regular and systematic physical exercises can contribute in a comprehensive way to the healthy ageing process by helping increase muscle strength, bone mineral density (hip and spine), and static and dynamic balance, ultimately decreasing the risk of falling. However, controversial results have been observed, with some studies indicating no improvement, especially in the risk of falls in older adults. Thus, the characteristics of the different physical exercise programs must be investigated. Research should discern which types of exercise reduce the risk of falling in the older adults. Thus, this systematic review study aimed to analyses the effects of physical training programs on the risk of falls in older adults. Falls in Older Adults: Systematic

which increase the incidence of sarcopenia and osteoporosis and make them more susceptible to falling [5].
Another factor associated with the risk of falling is the level of dependency of older adults, which can reach up to 14 times that of those with a high level of independence [6]. Regular and systematic physical exercises can contribute in a comprehensive way to the healthy ageing process by helping increase muscle strength, bone mineral density (hip and spine), and static and dynamic balance, ultimately decreasing the risk of falling [4,7,8].
However, controversial results have been observed, with some studies indicating no improvement, especially in the risk of falls in older adults [9][10][11][12]. Thus, the characteristics of the different physical exercise programs must be investigated. Research should discern which types of exercise reduce the risk of falling in the older adults, for example, isolated (strength, aerobic, and balance) or combined (balance/strength, aerobic/balance/strength, aerobic/ balance, and aerobic/strength). Thus, this systematic review study aimed to analyses the effects of physical training programs on the risk of falls in older adults.

Search Strategy
For the review study, we adhered to the guidelines for systematic reviews (PRISMA) Moher, et al. [13]. The search for eligible studies was carried out using four electronic databases (PubMed, BVS Regional Portal, British Library, and Library of Congress) until October 2019, without language restrictions. The terms used for the search were as follows: the search strategy combined terms covering the topics of population: (resistance training OR strength training) AND (balance training) AND (older OR elderly OR older adults) AND (risk of falling). The search was carried out using combinations of the following terms linked with Boolean operators "AND" (inter-group Boolean operator) and "OR" (intra-group Boolean operator). Duplicate studies were removed.
Three independent researchers analyzed titles and abstracts and then selected the articles relevant to the research.

Eligibility Criteria
Articles that met the following inclusion criteria were selected: (1) Original study; (2) Providing a description of the training program; (3) Having at least one of the following tests as a method of  The exclusion criteria were as follows: (1) Review articles; (2) Abstracts of unpublished conference papers and studies; and (3) No protocol for assessing balance or risk of falling.
According to the inclusion and exclusion criteria, 19 studies were excluded. The studies were evaluated in their entirety by two reviewers. Disagreements were decided by consensus, and when necessary, with the participation of a third reviewer. Eligible study references were also analyzed to identify other relevant studies.

Data Extraction
Independently, the same two reviewers extracted the following data from each selected study: name of the first author, year of publication, research title, age group (years), balance test, type of exercise used in the training program, weekly frequency of the training program, intensity and duration of the training program, training period in months, completion of the study, and periodicals in which the studies were published.

Evaluation of Methodological Quality of Studies
The quality evaluation of the eligible studies was carried out by two independent reviewers, with doubts resolved by consensus, and with the participation of a third reviewer when no consensus could be reached. The Physiotherapy Evidence Database (PEDro) scale was used to assess randomised clinical trials. The instrument consists of 11 items, the first of which is not computed in the final score. Thus, the scale has a score from 0 to 10 [14].

Study Selection
From the electronic databases (PubMed, BVS Regional Portal, British Library, and Library of Congress), 17727 studies were found.
*Item 1 does not contribute to the total score.

Discussion
This systematic review analyzed the effects of training programs on the risk of falling in older adults. We mainly aimed to elucidate whether the risk of falling is positively affected by isolated or combined training programs, and thus contribute to the prevention of falls and reduction in the risk of mortality. Regular exercise influenced total daily physical activity and possibly induced chronic physiological adaptations. We observed that all studies that combined strength training programs with balance exercises reduced the risk of falling [4,[16][17][18][19]21,22,24,26,29]. The same was seen in isolated strength training programs [15,20,24,25,27,30,33].
According to studies by Wolfson, et al. [34], Lord, et al. [35], and Howe, et al. [36], the findings of this review can in part be attributed to improvements in neuromuscular coordination by and "training specificity" of the programs applied in the studies cited here.
However, positive effects on muscle mass, strength, composition, power, and torque production, as well as changes in the mechanical properties of the tendon, must be observed to explain the significant reduction in the risk of falling [37,38]. Balance training, as well as the evaluation of this variable, is considered an essential component of fall prevention programs [39].
The loss of balance is directly related to decreases in muscle mass, strength, and proprioception. According to Teixeira, et al. No reduction in the risk of falling was also found in Varela, et al. [12], who used isolated aerobic training in older adults with mild cognitive impairment. According to Xu, et al. [40], aerobic activities can improve balance and generates a positive effect on the proprioception of older adults, given that aerobic exercises decrease gait instability and can decrease degenerative processes in the nervous and muscular systems. As such, aerobic exercises can contribute to decreasing the risk of falls in older adults [41].
In studies that used isolated balance exercises, Jacobson, et al. [32], Halvarsson, et al. [31], and Miko, et al. [23] reported a decrease in the risk of falling. However, these results were not observed in Hiyamizu, et al. [11]. A plausible explanation regarding the divergent results is the lack of non-standardized protocols in the experiments. According to Thomas, et al. [42], training programs that offer an approach that includes resistance exercises, aerobic components, and proprioception work can improve balance and reduce the risk of falling in older adults. Falls are multifactorial events that may be related to intrinsic and extrinsic factors. The incidence of falls increases each year in the older population worldwide, with a positive relation between age and the increase in cases of falls.
Older adults can have several complications after a fall, such as fractures and head injuries; indeed, falls account for 11% of the mortality rate in this population [43][44][45]. Thus, increased mortality in older adults is related to physical inactivity [46]. Moreover, Thomas, et al. [42] reported that low-intensity exercises improve the balance of older adults and contribute to decreasing the risk of falling; adherence to moderate-to high-intensity training programs is less attractive, leading to lower adherence, especially in older adults. Based on the studies above, and in recognition of the