Abstract
Objective
The objective of this study is to compare the effects of traditional resistance training (RT) vs. suspension training (ST) on functional performance, body composition, and cognitive functions in older adults.
Materials and Methods
Participants were categorized into three groups: the ST group (ST, n=8, age: 71), the traditional RT group (RT, n=8, age: 70), and the control group [(C), n=7, age: 70]. All measurements, assessments, and test evaluations were performed at the baseline, the sixth week, and the twelfth week. The training programs were conducted two days per week. The ST group was included in a program consisting of exercises with the suspension apparatus, whereas the RT focused on RT with body weight and free weights. The C was not included in the training program.
Results
The arm strength was greater in the ST group than in the C group (p=0.007). Muscle mass (p=0.029), basal metabolic rate (BMR) (p=0.034), agility and dynamic balance (p=0.012), leg strength (p=0.005), arm strength (p=0.002), and cognitive function (p=0.006) were significantly different in the ST group compared to the C group (p<0.05). The balance (p=0.005) and BMR (p=0.030) were significantly improved in the ST group compared to the RT group (p<0.05).
Conclusion
Physical therapists and trainers may use a suspension method as an alternative to traditional methods for older adults. This method may provide trainers with the opportunity to improve strength, balance, and cognitive function with a single training method.
Introduction
Resistance training (RT) is suggested as a beneficial treatment for sarcopenia and its effects (1-10). It also affects fat mass, balance, physical function, and muscle mass (11-19). However, some studies indicate that it does not significantly enhance physical function (20-23). Explosive RT with heavy loads is also recognized as more effective for muscle growth and strength in older adults (4, 24-26). However, many older adults engage in RT to maintain their daily activities and physical function rather than to increase muscle mass. For this reason, different approaches are needed to avoid excessive training loads and enhance functional performance more safely in older adults.
Suspension training (ST), also known as total resistance eXercise (TRX) (total RT), is more effective for core muscle activation (27-29) and has the potential to improve functional performance (27, 29-31). ST involves two straps that hang from a fixed point, with each strap’s length adjustable for various exercises. Older adults can safely participate in this training method without any additional loads. Previous studies have highlighted that ST is an effective alternative method for RT (32, 33). This method can potentially contribute to improving both physical function and body composition components (33, 34). However, it is still uncertain whether ST is more effective than RT for older adults (30, 32, 34).
Cognitive functions naturally decline with age (35). This decline may be due to reduced muscle strength and alterations in brain structure and function (36). Additionally, cognition is linked to balance ability and muscle mass. Alzheimer’s disease and cognitive impairment are also correlated with these factors (37, 38). Although some research suggests that aerobic fitness is associated with changes in brain structure and cognitive function (39), RT is also known to have the potential to enhance cognition (40-44). However, studies have shown that some resistance exercises do not improve cognitive function (45, 46).
Finally, RT is effective in improving some abilities and functions. However, lifting weights and gradually increasing resistance could pose risks, particularly for this age group. Furthermore, RT is not enough to improve balance and cognitive functions. Therefore, we hypothesized that ST might also influence cognition and balance without added loads. Thus, we aimed to provide data on ST for physiotherapists, physical trainers, and researchers working with the older population. The objective of this study is to compare the effects of RT vs. ST on functional performance, body composition, and cognitive functions in older adults.
Materials and Methods
Participants
All participants were reached by announcement at the Healthy and Active Aging Studies Research Center. They were aged 65-80 years, had no physical disabilities, did not use any assistive devices, reported participation in RT, had not undergone surgery in the past year, had trained for two years and had an Mini Mental State Examination Score of 23 or higher. Additionally, they do not use medication or supplements (protein, vitamin D/calcium, and vitamin B) that might contribute to increased strength were included in this study (Table 1). Participants used medications that might enhance muscle strength, had a physical disability, used an assistive device, had not trained for the past two years, had not reported participating in RT, had surgery within the last year, or used supplements such as protein, vitamin D/calcium, and vitamin B were excluded from the study.
Participants were randomly assigned to three groups. After randomization, the control group (C) was instructed to maintain their usual daily activities during the research. At baseline, 40 participants were included. However, some participants dropped out for various reasons, such as moving to another city, unexplained reasons, boredom, short-term illnesses, caring for grandchildren, or going on vacation (Figure 1). The participants were randomized into ST (n=8, female:6, male:2), RT (n=8, female:6, male:2), and C (n=7, female:4, male:3).
Procedure
Participants were involved in all tests and measurements at baseline six weeks, and post-training. The Montreal Cognitive Assessment Scale (MoCA) Turkish version was used to evaluate cognition (47, 48). The sit-to-stand test was used to assess leg functional strength (49). They were instructed to complete sit-stand cycles within 30 seconds. The arm curl test was used to evaluate functional strength. The participant was asked to fully bend their arm while holding dumbbells. The total arm curls were recorded in 30 seconds (dumbbell: 1 kg for women, 2 kg for men). Agility was assessed using the get-up-and-go test, and the participants were instructed to rise from the chair, walk to the end of the 2.5 m distance, and then return to sit down (49). The Turkish version of the Berg Balance Scale (BBS) was used for balance assessment (50). Body mass index (BMI), basal metabolic rate (BMR), fat mass, muscle mass, body fat percentage, and free fat mass (FFM) were evaluated using the bioelectrical impedance method (InBody 270, Co., Ltd.). Participants were instructed to avoid heavy exercise the day before and to finish their nutritional routines at least two hours before the test. All training programs and measurements were conducted at the Çanakkale Onsekiz Mart University Healthy and Active Aging Studies Research Center, Healthy and Active Aging Studies Research Center. This study was approved by Çanakkale Onsekiz Mart University Faculty of Medicine, Clinical Research Ethics Committee (decision number: 2022-03, date: 02.02.2022). Participants signed a written consent form. All participants were informed about the study and potential risks.
Interventions
Suspension Training: The ST consisted of exercises performed with TRX brand training equipment. Each strap was adjusted to each participant for different exercises. In the first week, researchers explained to the participants how to use this equipment safely. The training included squats, leg curls, rowing, chest press, butterfly, and arm curl exercises with TRX (Table 2).
Traditional Resistance Training: The RT included wall squats or single-leg squats, chair squats, elastic band knee flexion and extension, butterfly and arm curls with dumbbells, and chest presses with dumbbells (Table 2). All RT was applied in groups.
All training programs were conducted two days/week and lasted 40 minutes (including a warm-up~10 minutes and relaxing exercises 5 minutes).
The Rate of Perceived Exertion (RPE) scale was used to adjust the training load. The RPE scale was increased from the 2-3 range to the 4-5 range during the training period. In the first week, the exercises started with two sets of six repetitions, and by week 12, the sets were increased from 4 to 12 reps. The training variables (frequency, intensity, volume, and rest period) for all methods are presented in Table 2.
Statistics
The Shapiro-Wilk test was used to analyze the conformity of the data to the normal distribution. Differences between parameters that did not show normal distribution (arm curl, get-up-and-go) were analyzed using the Kruskal-Wallis test. Age, body mass, height, muscle mass, fat mass, body fat %, BMR, FFM, BMI, sit to stand, BBS Score, and MoCA Score results were analyzed using one-way ANOVA. The post-hoc Tukey test was used for differences between groups for parameters that follow a normal distribution. Differences between groups for parameters that did not follow a normal distribution were analyzed using the Mann-Whitney-U test. The paired samples t-test and Wilcoxon signed-rank test were used to determine the significance of the difference between baseline and post-period data within the group. The effect size (ES) was calculated by Cohen ES (>0.2 a small, 0.5 moderate, >0.8 large) (51). The significance level was set at <0.05. The SPSS 26.0 software was used in all analyses.
Results
There was no significantly different between ST, RT and C groups in age variable (ST =71.37±4.56, RT =70.87±3.97, C =70.00±3.21), height (ST =162.12±6.79, RT =161.62±5.52, C =164.00±6.58), and body weight (ST =72.25±8.20, RT =70.37±4.27, C =73.00±2.70) at the baseline (p>0.05). At the baseline, the age, body composition, physical and cognitive function scores were similar between the three groups (p>0.05, Table 3).
The BMI, BMR, FFM, fat mass, body fat %, muscle mass, and body mass were similar between baseline and week six in all groups (p>0.05, Table 3). Additionally, BBS, “get-up-and-go”, and “sit to stand” were not different between groups (p>0.05, Table 3). However, there was a significant difference in the arm curl test, and MoCA scores from baseline to week six in all groups (p<0.05). The arm curl score was higher in both training groups compared to the C group. Furthermore, the cognitive function score was higher in the ST group than the C group (p<0.05, Table 3).
No significant differences were observed among the groups in body mass, BMI, fat mass, body fat %, and FFM (p>0.05, Table 4). However, we observed significant differences in muscle mass, BMR, MoCA, BBS, the sit to stand test, arm curl test, and get-up-and-go test scores of older individuals. We observed that the increase in muscle mass in the ST group was greater than that of the C group (ST =27.50 kg, C =23.00 kg). Additionally, the BMR in the ST group was higher than that in the RT and C groups (ST =1492.12 kcal, RT =1331.62 kcal, C =1329.71 kcal). BBS in the ST was higher than in the RT (ST =53.62, RT =51.00). Get-up-and-go test (ST =5.25 sec, C =6.28 sec), arm curl test (ST =19.50 reps, C =13.42 reps), sit to stand test (ST =17.50 reps, C =14.85 reps), and MoCA Score were higher than the C group (ST =29.87, C =28.71).
There was a significant difference in arm curl (ES =0.25), sit-to-stand (ES =0.60), BBS Score (ES =1.79), get-up-and-go (ES =0.76), and MoCA Score (ES =0.86) between groups (p<0.05). Muscle mass, BMR; get-up-and-go; sit to stand; arm curl, and MoCA Scores were significantly higher in the ST than in the C group (p<0.05, Table 4). The arm curl score was significantly better in the RT group than in the C group. The BBS score and BMR were significantly higher in the ST than the RT group (p<0.05, Table 4).
Changes for the ST Over Time
We analyzed the data to assess differences between baseline and post-training periods. Significant improvements were observed in muscle mass (t=-4.339, p<0.05), fat mass (t=7.483, p<0.001), body fat % (t=9.000, p<0.001), FFM (t=-6.481, p<0.001), BMR (t=4.154, p<0.05), the get-up-and-go test (t=5.000, p<0.05), arm curl test (t=-3.454, p<0.05), and sit to stand test (t=-7.071, p<0.001). Additionally, there were notable improvements in the BBS Score (t=-3.476, p<0.05) and the MoCA Score (t=-4.583, p<0.05) when compared to other groups over time (Table 5).
Changes for the RT Over Time
In the RT Group, significant changes were noted in muscle mass (t=-2.497, p<0.05), body fat % (t=2.600, p<0.05), FFM (t=-3.100, p<0.05), BMR (t=-2.761, p<0.05), get-up-and-go test (t=4.583, p<0.05), arm curl test (t=-5.137, p≤0.001), and sit to stand test score (t=-5.400, p≤0.001) (Table 5).
Changes for the C Over Time
The fat mass (t=-2.500) showed a significant change over time (p<0.05, Table 5).
Discussion
The main finding of the present study was that both training methods improved certain body composition components, cognition score, and physical function in older adults. Another finding is that ST had a more significant impact on the BBS, MoCA cognitive function, body composition, and physical function compared to other groups. Considering the ES, ST is more effective for balance (ES =1.79), cognitive function (ES =0.86), and agility (ES =0.76) (Table 4).
A significant increase in BBS was observed for the ST group (p<0.05, Tables 3 and 4). ST engages more muscle groups and creates an unstable environment. This feature may explain why ST is more effective for neuromuscular control and balance compared to RT. Yu et al. (52) found that resistance exercises did not affect the BBS of older adults. Previous research shows RT alone does not effectively improve balance performance (23). Due to reduced balance, although force production declines in unstable conditions, RT on unstable surfaces is crucial for maintaining joint stability in the limb and trunk muscles. The relatively unstable position of ST significantly contributes to balance development and strength gains (33, 53). Thus, the impact of ST on balance scores can be attributed to the unique characteristics of this training method. We hypothesized that ST could produce different results due to its nature (Table 5). We recognize that our sample size is relatively small and requires validation through future studies with larger samples. However, we emphasize that our results have the potential to introduce new methods and practical applications in geriatric sciences.
Exercise is known to increase cell proliferation in the hippocampus (54) and to support cerebral blood flow, thereby enhancing neurogenesis and learning (55). Previous research has shown that RT is effective for cognitive function (56). In this study, a relatively small improvement was observed in the cognitive function scores of older adults in both training groups (p<0.05, Table 3). However, the results of this study showed that the scores of older adults in the ST group were higher than those in the other groups. Unlike the basic movement components, ST is performed in a suspended position. While this feature contributes to the physical functioning of older adults, it may also affect cognitive processes by causing strain on neural and learning pathways. Exercise activates more neurons, and a stimulating environment provides greater benefits for the brain (57).
Cognitive function is based on learning, repetition, memory, and the coordination of these processes. When cognitive stimulation is insufficient, no further neuron formation occurs (54). It is thought that ST may have encouraged learning and increased scores due to its unusual, somewhat complex, and relatively challenging structure. Interestingly, a notable increase in cognitive function was observed in the sixth week of the study (Table 3). However, there is no clear data on the correlation between exercise duration and cognitive function (58). We believe that this early development, indirectly influences the score due to exercise-induced neural adaptation (learning). MoCA is a simple and independent cognitive screening tool that is known for its superior sensitivity (47). Although the participants have a healthy cognitive state in this study, this difference suggests it may have a more significant impact on those with cognitive decline.
These results are consistent with previous studies that observed significant improvements after three months (59), twelve months (60), and six months (61). Although a longer exercise program does not result in greater cognitive benefits (62), future studies are necessary to identify the mechanisms that affect cognitive function in the older population.
The arm strength, leg strength, muscle mass, and agility improved significantly in two training groups (Table 3). However, a more significant difference was observed in older adults when ST was compared with the C group. Additionally, arm strength was identified as a second parameter that showed improvement after the sixth week (p<0.05, Table 3). It is believed that the early increase in arm strength may result from older adults’ limited training of their arm muscles. Similar to our research, Soligon et al. (32) found that both training methods had comparable effects on muscle mass, strength, and functional performance. The ST method can significantly enhance functional performance as it promotes greater activation of core muscles compared to RT (28). Jiménez-García et al. (31) reported that TRX training was effective in improving BMI, hand grip strength, and walking speed in older adults.
Study Limitations
This research has a few limitations. First, the sample size was relatively small. However, some studies demonstrate that ST can improve physical strength, balance, and overall quality of life among participants in a small sample size (32, 63). Second, participants’ dietary habits were not controlled in this study. They were only informed about supplements as part of the inclusion criteria and advised to maintain their usual dietary habits. Lastly, the effects of exercise on body composition can vary significantly between genders. However, due to an inadequate gender distribution in the sample group, a comparison between genders could not be conducted. Therefore, future studies should consider dietary habits and gender factors in older populations.
Conclusion
ST recommended as a safe method to improve physical function for adults aged 65 to 80 who prefer to avoid traditional RT. Physical therapists and trainers may use ST as an alternative to traditional methods for older adults. This method gives trainers the opportunity to improve strength, balance, and cognitive function. However, further studies are needed to evaluate the sustainability of training effects in the older population.


