A long-term physical activity training program increases strength and flexibility, and improves balance in older adults

Authors


Correspondence

Jesús Seco Calvo, Dpto. Enfermería y Fisioterapia, Universidad de León, Campus de Ponferrada, Avenida de Astorga s/n, C.P. 24400, Ponferrada, Spain.

E-mail: jasecc@unileon.es

Abstract

Purpose

Physical activity training programs in older adults have recognized health benefits. Evidence suggests that training should include a combination of progressive resistance, balance, and functional training. Our aim was to assess the effects of a simple physical activity program working on strength, flexibility, cardiovascular fitness, and balance in older adults, as well as the effects of a detraining period, at various different ages.

Methods

This was longitudinal prospective study, including a convenience sample of 227 independent older adults (54 men, 173 women) who completed a simple 9-month training program and 3-month detraining follow-up. The subjects were categorized into two age groups (65–74 [n = 180], and >74 years [n = 47]). At the beginning of the study (baseline), the end of the training period, and 3 months later (postdetraining), body mass index, body fat percentage, triceps skinfold thickness, hand grip strength, lower limb and trunk flexibility, resting heart rate, heart rate after exercise, and balance were measured, while VO2 max was estimated using the Rockport fitness test and/or measured directly.

Results

Significant improvements in strength (p < .0001), flexibility (p < .0001), heart rate after exercise (p < .0001), and balance (p < .0001) were observed at the end of the training program. Flexibility and balance (p < .0001) improvements were maintained at the end of the detraining.

Conclusion

A simple long-term physical activity training program increases strength in both sexes, improves flexibility in women, and improves balance in older adults. The results also indicate the importance of beginning early in old age and maintaining long-term training.

Introduction

It is known that worldwide populations are aging, and also that physical activity can play an important role in minimizing impairments characteristic of old age. Adopting a more active lifestyle and doing regular physical activity, including aerobic and resistance exercises, have been demonstrated to improve cardiovascular, respiratory, and musculoskeletal parameters in older adults (Intiso et al., 2012). Indeed, a recent review (Weening-Dijksterhuis, de Greef, Scherder, Slaets, & van der Schans, 2011) concluded that there is strong evidence supporting the positive effects of exercise training on physical fitness, functional performance, performance in activities of daily living, and quality of life in even in frail individuals. Data available suggest that such exercise programs should contain a combination of progressive resistance, balance, and functional training, such as exercises to improve gait.

Many types of exercise and their effects have been investigated in older adult populations. For instance, it has been reported that walking training may be an effective way to improve walking performance and delay mobility impairment in older adults (Malatesta, Simar, Saad, Préfaut, & Caillaud, 2010), whereas strength and coordination training can reduce postural tremor amplitude in elderly individuals (Keogh, Morrison, & Barrett, 2010). A program of multicomponent training with weight-bearing exercises was found to improve bone density, muscle strength, and balance in older women (Marques et al., 2011), this last point being especially important as balance is a prerequisite for mobility (Frank & Patla, 2003). Furthermore, it has been shown that explosive resistance training enables older adults to reach higher peak power outputs with heavier loads without losses in movement velocity (de Vos et al., 2008).

On the other hand, it has also been suggested that supervised stretching is effective to improve various aspects of gait (Cristopoliski, Barela, Leite, Fowler, & Rodacki, 2009). Notably, after a stretching protocol, older adults displayed gait parameters similar to those reported in young healthy adults. These authors concluded that stretching can be used as an effective means to improve range of motion and reverse some age-related changes that influence gait performance. The results of another study (Batista, Vilar, de Almeida Ferreira, Rebelatto, & Salvini, 2009) indicate that in older women an active stretching program is effective for increasing the flexibility of knee flexors, extensors and flexor torque, as well as functional mobility.

As for weight control, relatively little is known about the impact of body mass index (BMI) on self-report and performance-based balance and mobility measures in older adults (Hergenroeder, Wert, Hile, Studenski, & Brach, 2011). Nevertheless, older adults with severe obesity usually show a greater impairment in mobility than those who are less obese, and it should be taken into account that even less obese individuals also show a significant decline in mobility (Hergenroeder et al., 2011). However, it has also been shown that low fitness in old age is associated with greater weight loss and loss of lean mass, than observed at higher levels of fitness, and such changes in body composition also imply a greater risk of morbidity, disability, and even mortality (Koster et al., 2010). Overall, physical exercise may help maintain a normal healthy weight, avoiding both excessive weight gain and loss.

As well as muscular strength and body composition, programmed accommodating circuit exercise training has been shown to have beneficial effects in older adults on cardiorespiratory fitness and cholesterol levels (Takeshima et al., 2004). Specifically, aerobic exercise elicits a significant improvement in cardiorespiratory fitness in older individuals (Forster et al., 2009). It has also been suggested that cycle ergometry is sufficient stimulus to improve neuromuscular function in older men, although gains may be quickly lost with detraining (Lovell, Cuneo, & Gass, 2010).

In general, aging is associated with a reduction in strength. It has been reported that although men's grip force tends to exceed that of women, their hand-force declines more steeply, indicating that sex differences in strength decrease with age and that at older ages both men and women tend to develop this type of disability (Jansen et al., 2008). Standard types of rehabilitation protocol do seem to produce improvements in physical performance, but it may also be useful to explore differences between the sexes to help plan new rehabilitation interventions (Niemelä, Leinonen, & Laukkanen, 2011).

Lastly, we note that Bird, Hill, Ball, and Williams (2009) compared community-based resistance and flexibility programs in untrained older adults: resistance training resulted in a significant increase in strength, no such improvement being seen in the flexibility only intervention, whereas balance performance significantly improved after both resistance training and standing flexibility training. Such results underline the need to combine various type of physical training to obtain the greatest benefits.

In summary, multicomponent physical activity programs have an important role to play in maintaining physical health and well-being among the elderly. At the same time, for such programs to be sustainable and reach as many of the target population as possible, it is clearly desirable to avoid complex costly programs. Given all this, the purpose of our study was to assess the effects of a simple 9-month physical activity program working on strength, flexibility, cardiovascular fitness and balance in older adults of both sexes, as well as the effects of a 3-month detraining period, at various different ages.

Methodology

Participants

We assessed 1206 potential participants from Salamanca (Spain) for eligibility to participate in a 9-month training program, consecutively recruited 247 of these for the intervention when they visited a health center, and included in the analysis those who completed assessments at the end of 3-month follow-up (n = 227). Consistent with the requirements of the Declaration of Helsinki, all subjects gave written informed consent before inclusion. The following parameters were measured at the beginning (baseline) and end of the training period, as well as 3 months later (postdetraining): BMI, body fat percentage, triceps skinfold thickness, hand grip strength, lower limb and trunk flexibility, resting heart rate, heart rate after exercise, and balance, as well as VO2 max, directly and/or an estimate using the Rockport fitness test estimate. The flow of participants through each stage of the study is shown in Figure 1. The final sample size was n = 227 (54 men, 173 women).

Figure 1.

The Flow of Participants Through Each Stage of the Study.

Inclusion Criteria

A physical condition assessment was performed before inclusion of older adults in the program, and its results were taken into account as a possible exclusion criterion. That is, it was necessary to ensure that the physical condition of each potential participant was sufficiently good to enable him/her to participate in the physical activity training carried out in this study, and thereby avoid unreasonable risks. All participants were then followed up to assess whether there were changes in the parameters measured attributable to the exercise program.

An initial assessment was made using a questionnaire that recorded personal data, age, and other sociodemographic data. Subjects’ degree of interest in and regular level of physical activity, as well as a detailed medical history, including pharmacological treatments, were also detailed. A physical examination of musculoskeletal system was performed, and heart rate and blood pressure were measured. All these data provided a general health evaluation to ensure early identification of any absolute or relative contraindications, or limitations on physical exercise.

Given all this, the inclusion criteria were: to be at least 65 years of age; have given written informed consent; have passed the medical examination, having the minimum physical condition to carry out the proposed exercise program and no absolute or relative contraindication to exercise or activity restrictions; and then attend the end-of-program and 3-month follow-up assessments as well as at least 80% of the training sessions.

Exclusion Criteria

Candidates were excluded for failing the physical condition examination before the study period, and subsequently participants were excluded for attending training sessions with inappropriate clothing for sports, absence from more than 20% of the sessions, or refusal to sign the consent inform and/or the attendance register.

Other exclusion criteria were based on reviewing past medical records. Specifically, candidates were excluded if they had certain medical conditions, namely decompensated heart failure, acute myocardial infarction, myocarditis, angina pectoris, untreated severe hypertension, valvular heart disease, aortic aneurysm, cardiomegaly with gallop rhythm, aortic embolism, pulmonary heart disease, heart rhythm disorders, vein occlusion (thrombophlebitis), acute infections, respiratory failure, psychosis, and uncontrolled epilepsy or diabetes.

Study Variables

A range of complementary examinations was made to evaluate physical condition, namely:

Balance Testing, with eyes open and shut, in closed and partially closed kinetic chain positions. These static balance sessions were performed individually with the subject on a force-measuring and balance-training platform (Metitur Good Balance 200 System®, Metitur Ltd., Jyväskylä, Finland). The platform system converts changes in weight distribution to a quantitative measurement of mediolateral and anterior-posterior sway over a certain period of time (Ceria-Ulep et al., 2010): the larger the area, the poorer the balance. An example of output of this system is shown in Figure 2. We assessed the participants standing first on a hard and then a foam surface for 15 and 30 second intervals.

Figure 2.

The Platform System Converts Changes in Weight Distribution to a Quantitative Measurement of Mediolateral and Anterior-Posterior Sway Over a Certain Period of Time.

Trunk flexibility: For this, we used the most common way to measure lower back and hamstring flexibility, namely, the sit and reach test (Osness et al., 1996). We made the test kit from a solid box about 30 cm high, with a meter rule attached extending 26 cm beyond the front edge of the box toward the subject. Subjects remove their shoes and sit on the floor with their legs stretched out in front of them with knees straight and feet flat against the front end of the test box. They are instructed to lean forward, in a slow, steady movement, bending at the hips, keeping their knees straight and sliding their hand up the ruler as far as they are able to reach. When each subject has stretched forward as far as they can, the result is recorded (in cm); they are allowed to rest, and then repeat the test a further two times, that is, three times in total. We used the mean of these results as the final score.

Body Composition: A stadiometer (SECA®, Hamburg, Germany), with a range of 130–210 cm and accurate to the nearest 2 mm, was used to measure height of the selected subjects. Body weight was measured using weighing scales (SECA), with a range of 2–130 kg and accurate to the nearest 0.2 kg. These measurements were then used to calculate the BMI. We considered the following categories: <19 kg/m2 (underweight), 19–24.9 kg/m2 (normal), 25–29.9 kg/m2 (overweight), 30–34.9 kg/m2 (moderate obesity), 35–39.9 kg/m2 (severe obesity), and >40 kg/m2 (morbid obesity). In addition, triceps skinfolds were measured on the non-dominant side of the body using Harpenden Skinfold Calipers® (Holtain, Dyfed, UK; constant pressure, 10 g/mm2 and accurate to the nearest 0.2 mm), and we recorded the mean of three measurements. Finally, bioelectrical impedance analysis measurements were used for body composition analysis (impedance meter; MALTRON® BF-906, Rayleigh, UK), obtaining an estimate of body fat percentage.

Muscle Strength: Hand grip strength was determined using a Jamar® hydraulic hand dynamometer (Sammons Preston, Bolingbrook, IL). The hand dynamometer was first calibrated. The position for measuring the handgrip force was with the hand forward and elbow at a 90° angle. We then recorded the mean of three measurements of the force (using the maximum in each repetition) and always in the dominant-hand in each participant.

Aerobic Capacity: An endurance test was carried out to assess aerobic capacity, cardiovascular response, and tissue oxygen consumption. Specifically, VO2 max was estimated in most participants using the Rockport fitness test (1 mile walk) and was also measured directly, when it was judged that this would not represent an unreasonable risk to the individual. The subjects undergoing the Rockport fitness test had to walk a distance of 1 mile (1609.3 m), the time to complete the walk and their final heart rate being measured. The value of VO2 max was then calculated with the following equation: VO2 max = 132.6 − (0.17 × body mass) − (0.39 × age) + (6.31 × sex) − (3.27 × time in minutes) − (0.156 × heart rate), where for sex, Male = 1 and Female = 0. This method is user friendly and provides a relatively accurate estimate.

Physical Activity Program

This was a group activity, but with no more than 20 subjects participating in any given session. Furthermore, it was ensured that the activity was carried out in suitable conditions. Specifically, there was proper lighting and ventilation, the room temperature being kept at 18–20°C, and a sufficiently large area (around 50 m2) was covered with exercise mats to avoid injuries. Sessions lasted at most 50–55 minutes, with two sessions a week. Participants were instructed to wear suitable cotton sports clothing. Each session began with a 5- to 7-minute period of stretching of the main muscle groups, followed by mobility and strength exercises lasting 15 minutes. Then, a slow walk commenced. If all in the group were able to run, the pace was progressively quickened to a run, and, after <1 minute running, participants returned to a slow walk. Otherwise, all participants continued walking, increasing the length of their stride. In both cases, this aerobic exercise (walking/running) lasted for a total of about 3 minutes.

This was followed by a rest, with hydration (water or fruit juice). Subsequently, for a period of 15–20 minutes, coordination and balance exercises were performed with balls and other materials, combined with cooperative games (e.g., keeping a ball or balloon in the air). Finally, the session ended with breathing exercises and relaxation. Each participant's heart rate was measured at the beginning of each session (resting heart rate) at the end of the session (heart rate after the aerobic exercise). It was taken into account that excessive loads on the dorsal region, or extreme movements of trunk and neck were contraindicated given the age of the participants. The training was carried out three times a week, for at least 36 weeks.

The follow-up over the course of study was as follows. An initial evaluation was carried out just before starting the training (baseline). A second evaluation was made 9 months after starting the program of physical exercise (posttraining). Finally, there was a third evaluation 3 months later (postdetraining), completing the full year of the study. Each evaluation included the recording of health-related events, such as any changes in previous symptoms, as well as measurements of balance, flexibility, body composition, coordination, muscle strength, and aerobic capacity, to detect any changes that might have been induced specifically by physical activity. Participants’ attendance and participation in the program were also recorded.

Statistical Analysis

Data obtained were normally distributed (Shapiro–Wilk test). Accordingly, comparisons of the values obtained at different points in the study were made using the Student's t-test, with a 95% confidence level (p < .05). All data were presented as mean ± SEM. Independent analysis was also performed considering subgroups of the participants by sex and age. The SPSS software package was used for all the analysis (version 17.0; Chicago, IL).

Results

Of the 247 recruited, 227 independent older adults (age 65–84 years; mean 70.53 ± 4.90) from Salamanca (Spain) completed a 9-month training program (Table 1).

Table 1. Sample Distribution by Sex and Age
 65–74 (years)>74 (years)Total
n (%)n (%)n (%)
Men43 (18.943)11 (4.8458)54 (23.79)
Women137 (60.352)36 (15.859)173 (76.21)
Total180 (79.295)47 (20.705)227

Data for the full sample are detailed in Table 2. In general, there was found to be an increase in strength (p < .0001) that was maintained to the end of the detraining period, both in men and women (Tables 2-4). The exception was that no significant changes in strength were observed in the case of subjects older than 74 years of age (Table 6).

Table 2. Statistical Analysis of the Parameters Measured for the Total Sample, Where Measurement 1 Was Taken at Baseline, Measurement 2 after the Training Period, and Measurement 3 after the Detraining Period
  n Measurement 1 p Measurement 2 p Measurement 3
M SD M SD M SD
Body mass index (kg/m2)12729.884.15n.s.29.84.24n.s.304.22
Body fat (%)12129.256.29n.s.29.156.59.00129.576.44
Tricipital fold (mm)126216.54n.s.20.556.82n.s.20.376.82
Hand grip force (kg)1280.530.15.0000.620.25n.s.0.60.28
Flexibility (cm)16514.946.5.00017.136.18.00015.456.14
Resting heart rate (beats/min)10774.389.74n.s.73.229.82n.s.72.887.37
Rockport test (mL/kg per minute)9117.721.53n.s.17.51.51n.s.17.61.66
Heart rate after exercise (beats/min)8998.1118.51.000107.6415.98n.s.103.7319.17
VO2 max (ml/kg per minute)4221.946.94n.s.21.295.91n.s.21.896.31
Balance (mm2)174425.26399.05.000300.78329.04.041319.78441.58
Table 3. Statistical Analysis of the Parameters Measured for the Male Subgroup, Where Measurement 1 Was Taken at Baseline, Measurement 2 after the Training Period, and Measurement 3 after the Detraining Period
  n Measurement 1 p Measurement 2 p Measurement 3
M SD M SD M SD
Body mass index (kg/m2)2728.514.24n.s.28.444.23n.s.28.424.28
Body fat (%)2725.045.89n.s.24.796.16n.s.25.096.23
Tricipital fold (mm)2613.73.76.00011.113.24n.s.10.853.43
Hand grip force (kg)270.690.16.0000.890.28n.s.0.850.36
Flexibility (cm)3215.347.52n.s.16.696.72n.s.15.477.1
Resting heart rate (beats/min)2371.5710.25n.s.72.438.8n.s.71.176.56
Rockport test (mL/kg per minute)2416.681.36n.s.16.361.71n.s.16.431.65
Heart rate after exercise (beats/min)23100.3318.94.033107.6717.41n.s.104.3321
VO2 max (mL/kg per minute)1128.565.13n.s.26.494.85n.s.27.656.47
Balance (mm2)37462.16457.6n.s.342.32346.62n.s.335.84339.94
Table 4. Statistical Analysis of the Parameters Measured for the Female Subgroup, Where Measurement 1 Was Taken at Baseline, Measurement 2 after the Training Period, and Measurement 3 after the Detraining Period
  n Measurement 1 p Measurement 2 p Measurement 3
M SD M SD M SD
Body mass index (kg/m2)10130.244.07n.s.30.164.18n.s.30.424.12
Body fat (%)9430.465.90n.s.30.406.18.00130.865.92
Tricipital fold (mm)10022.905.72n.s.23.015.15n.s.22.845.07
Hand grip force (kg)1010.490.11.0020.540.18n.s.0.530.21
Flexibility (cm)10214.826.17.00017.276.02.00015.445.82
Resting heart rate (beats/min)8475.159.51n.s.73.4410.12n.s.73.357.54
Rockport test (mL/kg per minute)6718.101.42n.s.17.911.20n.s.18.021.46
Heart rate after exercise (beats/min)6597.2918.43.000107.6315.57n.s.103.5118.62
VO2 max (mL/kg per minute)3119.595.94n.s.19.445.14n.s.19.844.89
Balance (mm2)122414.07380.90.000288.18323.94n.s.314.91469.18

A significant increase in flexibility was detected in the case of women (p < .0001; Table 4) and all those in the 65- to 74-year-old age group (p < .0001) (Table 5), but no such changes were observed in men (Table 3). However, in general, the gain in flexibility was lost after the detraining period. On the other hand, the slight improvement (p < .001) obtained in the subjects older than 74 years of age was maintained after detraining (Table 6).

Table 5. Statistical Analysis of the Parameters Measured for the Subgroup of 65–74 years Where Measurement 1 Was Taken at Baseline, Measurement 2 after the Training Period, and Measurement 3 after the Detraining Period
  n Measurement 1 p Measurement 2 p Measurement 3
M SD M SD M SD
Body mass index (kg/m2)10629.804.18n.s.29.784.31n.s.29.954.25
Body fat (%)10229.076.48n.s.29.026.80.05029.416.61
Tricipital fold (mm)10521.046.76n.s.20.617.03n.s.20.527.17
Hand grip force (kg)1070.530.14.0000.630.25n.s.0.600.28
Flexibility (cm)10315.516.42.00017.576.34.00015.756.19
Resting heart rate (beats/min)9173.759.70n.s.72.789.95n.s.72.567.43
Rockport test (mL/kg per minute)8117.691.52n.s.17.471.56n.s.17.491.56
Heart rate after exercise (beats/min)7997.6718.56.000107.5915.87n.s.103.2418.51
VO2 max (mL/kg per minute)3721.807.27n.s.21.346.30n.s.21.896.69
Balance (mm2)124457.97432.04.000317.90358.06n.s.322.52480.97
Table 6. Statistical Analysis of the Parameters Measured for the Subgroup of More Than 74 years, Where Measurement 1 Was Taken at Baseline, Measurement 2 after the Training Period, and Measurement 3 after the Detraining Period
  n Measurement 1 p Measurement 2 p Measurement 3
M SD M SD M SD
Body mass index (kg/m2)2330.254.08n.s.29.863.97n.s.30.254.17
Body fat (%)1930.195.22n.s.29.825.40.03530.425.48
Tricipital fold (mm)1920.785.40n.s.20.245.76n.s.19.604.68
Hand grip force (kg)210.520.19n.s.0.540.21n.s.0.600.31
Flexibility (cm)3112.996.50.00115.635.41n.s.14.385.91
Resting heart rate (beats/min)1678.009.41n.s.75.758.97n.s.74.696.94
Rockport test (mL/kg per minute)1018.011.70n.s.17.790.98n.s.18.502.21
Heart rate after exercise (beats/min)10101.6018.69n.s.108.0017.79n.s.107.6024.62
VO2 max (mL/kg per minute)523.004.03n.s.20.920.99n.s.21.892.34
Balance (mm2)35309.37216.77n.s.240.11185.59n.s.310.09262.94

Heart rate after physical activity increased after the training program (p < .0001), and this increase was maintained after the detraining period in all groups (Tables 2-5), except for those subjects older than 74 years of age (Table 6). In contrast, there were no significant changes in VO2 max.

An improvement in balance was observed after the training program (p < .0001). Considering all the participants, although beneficial effects on balance continued to be detected in the evaluation made after the detraining period (p < .041), they tended to be less evident than at the end of the 9 months of training (Table 2). However, in the case of women (Table 4) and subjects 65–74 years of age (Table 5), the improvement in balance was maintained to the end of the detraining period. On the other hand, in men and subjects older than 74 years of age, no significant changes were observed at that stage (Table 6).

Finally, in the case of men, a significant reduction in triceps skinfold thickness was observed from baseline to after the exercise program (p < .0001) (Table 3). Further, on average, an increase in body fat percentage was observed by the end of the detraining period (p < .001), especially among subjects aged 65–74 years old (p < .050) (Table 5).

Discussion

In our study, we found significant increases in strength and improvements in both flexibility and balance after a simple training program, and not all gains were quickly lost with detraining, but the benefits varied by both sex and age.

A 15%–20% reduction in strength has been reported in every decade after 50 years of age, leading to deleterious effects on the performance of basic activities of daily living (American College of Sports Medicine, Chodzko-Zajko, Proctor, Fiatarone Singh, & Minson, 2009). Consistent with this, one study found that 26% of adults over 70 years of age could not easily climb stairs, 31% had problems carrying a bag weighing 35 kg, and 36% had walking difficulties (Stump, Clark, Johnson, & Wolinsky, 1997). A reduction in strength in upper and lower limbs is associated with poor performance in activities of daily living (Fried, Ettinger, Lind, Newman, & Gardin, 1994; Lawrence & Jette, 1996), and poor hand grip strength, in particular, predicts accelerated dependency in activities of daily living and cognitive decline among the oldest old (Taekema, Gussekloo, Maier, Westendorp, & de Craen, 2010; Lawrence & Jette, 1996). Indeed, Taekema et al. showed that hand grip is a predictive factor for disability in older adults.

In this context, it is well-known that progressive resistance strength training exercises promote an increase in muscle strength. Moreover, it has been demonstrated that they can have a positive effect on some functional limitations in older adults (Latham, Anderson, Bennett, & Stretton, 2003). In fact, in older individuals, muscular strength and endurance tend to improve functional independence and quality of life, regardless of whether they have cardiovascular disease, and also reduce disability (Williams & Stewart, 2009).

Accordingly, our finding of an increase in strength after an easy-to-implement training program that was maintained after a detraining period, both in men and women, is a positive result. On the other hand, although it has been demonstrated in older adults that an 8-week muscle strength exercise intervention focused on lower limb strength exercises of light-to-moderate intensity (that is, exercise training, even of short duration and light-to-moderate intensity) can increase muscle strength, whereas decreasing fall risk among nonagenarians (Serra-Rexach et al., 2011), we observed no significant changes in the case of subjects aged over 74 years of age.

Another age-related change is loss of flexibility and this is a deleterious factor for a great number of functions related to mobility (Konczak, Meeuwsen, & Cress, 1992). Specifically, it has been shown that the maintenance of lower limb flexibility is relevant to preventing low back pain, as well as maintaining balance and a reduced risk of falls (American College of Sports Medicine et al., 2009). In our study, a significant increase in flexibility was observed in the case of women, suggesting that training could be useful to prevent skeletal disorders derived from falls, which are a severe problem, especially in older women. However, this gain in flexibility tended to be lost after a detraining period, indicating the need to maintain the training program in the long term. It should also be noted that, although subjects older than 74 years of age maintained the training-induced flexibility gain after the detraining period, the gain after the program had been relatively small, meaning that overall the usefulness of the physical exercise in such cases was somewhat limited.

It has been demonstrated that an increasing peak aerobic capacity for walking (VO2 peak) by interval walking training is closely linked with decreasing indices of lifestyle-related diseases in middle-aged and older people (Morikawa et al., 2011). However, it has also been found that the goal of combined endurance and strength training (increasing both aerobic capacity and maximal strength simultaneously) may only be achieved by some older subjects (Karavirta et al., 2011). Consistent with this, we observed no significant changes in VO2 max after the training period. On the other hand, it is well known that aerobic physical activity is a determinant factor in the preservation of functional capacity in the elderly (Wang, Ramey, Schettler, Hubert, & Fries, 2002), and, as could be expected, we observed that heart rate immediately after physical activity increased after the training program.

As we noted earlier, balance is another important factor conditioning mobility (Frank & Patla, 2003). Furthermore, deficits in postural control and muscle strength represent important intrinsic fall risk factors (Granacher, Muehlbauer, Zahner, Gollhofer, & Kressig, 2011), and, among older adults, are correlated with functional independence to perform the basic activities of daily living (Drusini et al., 2002). In this study, an improvement in balance was observed by the end of the training program. In the case of women, the improvement in balance was maintained to the end of the detraining. On the other hand, we note that the period considered was only 3 months, and considering the overall sample the beneficial effect on balance tended to be lost after even this length of detraining period. Again, our results indicate a need to maintain such programs over time.

Several of our findings highlight this need for longer term programs. An assessment of the cost-effectiveness of such a measure is beyond the scope of this article, but given that, our results demonstrate that this type of simple program seems to be effective; such financial/economic analysis would be an interesting area for future research.

The improvement in balance was best maintained after the detraining period among subjects 65–74 years of age. Similarly, the increase in heart rate during physical activity at the end of the training program was maintained after the detraining period in the younger participants, but not among subjects older than 74 years of age. Further, no significant changes in strength were observed in the case of subjects older than 74 years of age. All these findings indicate the importance of promoting physical exercise habits from the beginning of old age or earlier.

A loss of muscle mass, as well as redistribution and reduction in body fat percentage with age, has been described in older people and seems to be more severe in women (Coqueiro Rda, Barbosa, & Borgatto, 2009). On the other hand, it has also been suggested that an increase in BMI could be related to functional limitation in elderly women (Davison, Ford, Cogswell, & Dietz, 2002; Zoico et al., 2004). Furthermore, unlike strength and lean body size, both adiposity and physical performance were found to be associated with disability risk, suggesting that these characteristics should be considered as risk factors for disability (Cawthon et al., 2011). In our study, we found a significant reduction in triceps skinfold thickness from baseline to the end of the training period in men. Moreover, an increase in body fat was observed after the detraining period, in the sample overall but particularly in the subjects aged 65–74 years of age. These are both further indicators of the positive effects of such a training program.

The relatively high number of drop-outs (see Figure 1), and lack of cost-effectiveness analysis are limitations of this study. On the one hand, given that our results demonstrate that this type of simple program can be effective, although beyond the scope of this study as noted earlier, cost-effectiveness analysis should be conducted in the future. On the other hand, despite the drop-out rate, we obtained a reasonably large final sample size, sufficient to allow analysis by age and sex. Accordingly, we consider that our findings are a useful contribution to understanding the positive effects of exercise among older adults.

Due to population aging, an increase in the number of older adults is expected in near future. In particular, the 85-and-older segment of the population continues to be the fastest growing group. Indeed, there is a new category of older adults: the elite old (as opposed to the young, middle, and oldest old), corresponding to those over 100 years of age. In this context, the differences in the effect of training as a function of age that we detected are particularly interesting and highlight the need to investigate the impact of exercise among the oldest age groups. In this context, we believe that the differences we detected, although relatively small, may be clinically relevant. Chronic diseases usually develop with age, and taking into account that it is desirable for older adults to maintain the best possible level of wellness, more research and translation to practice are needed in the field of rehabilitation nursing to achieve this objective.

Taken together, our results corroborate the view that physical activity increases strength, an improvement that was maintained after a detraining period both in men and women; improves flexibility, although only in the case of women, and this tended to be lost after a detraining period; and improves balance, a significant improvement being observed by the end of the training program, this being best maintained after the detraining period among subjects 65–74 years of age.

In conclusion, a long-term physical activity training program increases strength and flexibility, and improves balance in older adults. Also, our findings indicate the importance of promoting physical exercise habits from the beginning of old age and indicate that training should be maintained in the long-term.

Acknowledgments

We thank the City Council of Salamanca (Spain) for funding and collaboration enabling us to carry out this study.

We thank Prof. J.R. Revelatto for collaboration.

No benefits in any form have been or will be received from a commercial party related directly or indirectly to the subject of this article.

The authors do not have any conflicts of interest to report.

Key Practice Points

  • It is well known that strength training promotes an increase in muscle strength. Moreover, it can prevent several functional limitations in olders. In fact, muscle strength is correlated with functional ability.
  • A significant increase in flexibility was observed in the case of women, suggesting that a long-term training could be useful to prevent skeletal disorders derived from falls, which are an important problem, especially in older women. However, this gain in flexibility was lost after a detraining period, indicating the necessity of maintaining the training program.
  • Heart rate during physical activity increased after the training program, and this increase was maintained after the detraining period in all groups, except in those subjects aged more than 74 years, indicating that training period should be maintained throughout the time, and begin in the initial phase of elderly.”
  • An improvement in balance was observed after detraining program; this beneficial effect was lost after the detraining period, indicating the necessity of maintenance of the program throughout.

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