Maintenance Effects of a DVD-Delivered Exercise Intervention on Physical Function in Older Adults

Abstract

Background.

Exercise training has been demonstrated to enhance physical function and to have a protective effect against functional limitations and disability in older adults.

Purpose.

The objective of this study was to determine whether the effects of a home-based, DVD-delivered exercise intervention on functional performance and limitations were maintained 6-month postintervention termination.

Methods.

Follow-up assessments of functional performance and limitations were conducted in a sample of community-dwelling older adults (N = 237) who participated in a 6-month randomized controlled exercise trial. Participants were initially randomized to a DVD-delivered exercise intervention or an attentional control condition. The Short Physical Performance Battery, measures of flexibility and strength, and functional limitations were assessed immediately before and after the intervention and then again 6 months later. Analyses of covariance were conducted to examine changes in physical function between the two conditions at the end of the intervention to 6-month follow-up.

Results.

There were statistically significant adjusted group differences in the Short Physical Performance Battery (η² = 0.03, p = .01), upper-body strength (η² = 0.03, p = .005), and lower-body flexibility (η² = 0.02, p = .05), indicating that gains brought about by the intervention were maintained 6 months later.

Conclusions.

A DVD-delivered exercise program specifically designed to target elements of functional fitness in older adults can produce clinically meaningful gains in physical function that are maintained beyond intervention cessation.

Successful aging is highly dependent on the maintenance of physical function in older adults (1). However, the aging process is inherently associated with an array of negative health-related consequences, including greater physical limitations, poorer functional performance, and increased levels of disability. These age-related declines can have major repercussions on the physical, mental, and social health of older adults. According to the Centers for Disease Control and Prevention, nearly one third of adults aged ≥65 years experience moderate to severe declines in functional performance which has significant implications for mobility (2). These functional decrements are further accelerated by poor lifestyle choices and behaviors, such as physical inactivity (3,4). Given that the older adult population is projected to more than double by 2050 (5), it is imperative for researchers and clinicians to develop and identify new, innovative strategies aimed at minimizing the magnitude of declines in functional performance in older adults. Indeed, reducing the proportion of older adults who experience moderate to severe limitations in physical function has been identified as a major public health goal (6).

Regular, sustained participation in physical activities, including targeted exercises, can significantly offset the declines in physical function that are associated with aging (7,8). Furthermore, in some cases, these benefits may be maintained up to 2 years following the cessation of formal activity (9). In a recent study, we reported the efficacy of a 6-month, DVD-delivered, home-based exercise program for improving flexibility, strength, and balance outcomes in a sample of older adults (ie, the FlexToBa Trial) (10). When compared with an attentional control condition, which received a DVD focusing broadly on topics of healthy aging, the FlexToBa DVD condition evidenced clinically significant improvements in the Short Physical Performance Battery (SPPB) (11,12) and significant gains in upper body strength and lower body flexibility. Our findings were consistent with the extant evidence that suggests behavioral interventions can generally produce positive, albeit short-term, changes in physical activity behaviors and health-related benefits (13,14), although such improvements brought about by exercise training are maintained beyond program termination is unclear.

Herein, we report on the maintenance of improvements in functional performance resulting from the FlexToBa intervention 6 months after its cessation in the absence of any telephone contact or feedback. We hypothesized that the DVD-delivered home-based exercise program would sustain or possibly increase 6-month gains relative to the attentional control condition.

Methods

Study Design and Interventions

Details regarding study development, design, and delivery have been reported elsewhere (10,15). In brief, low-active community-dwelling older adults were recruited across a 5,000 square mile radius of east-central Illinois to participate in a 6-month study examining exercise training effects on functional performance and functional limitations. Participants who met all eligibility criteria and completed baseline testing were randomized to one of two conditions: a 6-month, home-based, DVD-delivered exercise training intervention designed to improve flexibility, toning, and balance (ie, FlexToBa) or a DVD-delivered Healthy Aging intervention that focused on a wide array of health topics relevant to aging. The FlexToBa program includes three sequential DVDs consisting of program introduction and safety principles plus six progressive exercise sessions, each with two sets of 11–12 balance, strength, and flexibility exercises (15). All exercises were modeled by a trained exercise leader assisted by age appropriate models who demonstrated modifications of each exercise. The Healthy Aging DVD was a commercially available documentary produced by Dr Andrew Weil (16). Both groups received titrated telephone support calls and staff contact across the trial; this did not occur during the 6-month follow-up after formal intervention cessation. Assessments occurred at centrally located venues (eg, regionally accessible fitness centers, hotel conference rooms, etc.) and were conducted by blinded research assistants at baseline, 6th month (ie, postintervention), and 12th month (ie, 6-month follow-up).

Primary Outcome Measures

Functional performance

The SPPB assesses three components of physical function (ie, balance, mobility, and lower-leg strength) and was used as the primary measure of functional performance (17). Following SPPB protocol, individual scores were calculated for each test of physical function, as well as an aggregated summary score of overall functional performance (possible range = 0–12), with higher values indicating better performance. In addition, several components from the Seniors Fitness Test (18,19) were used to assess additional aspects of physical function, including upper body strength and endurance via a 30-second arm curl task and upper and lower body flexibility via a back-scratch and sit-and-reach task, respectively.

Functional limitations

The abbreviated function component of the Late-Life Function and Disability Instrument (20,21) was used as a subjective evaluation tool for functional limitations. Using a 5-point Likert scale, this questionnaire assesses the degree of difficulty experienced with upper-extremity function and basic and advanced lower-extremity function. These three subscales were scored and combined to provide a total functional limitations score, with higher scores indicative of improved function.

Follow-Up Program Adherence

In an effort to determine the extent of activity maintenance in the DVD-delivered exercise condition, participants were asked to voluntarily complete an anonymous program evaluation and feedback form (n = 105). Questions on this form asked participants to evaluate their current level of physical activity and to indicate how many days per week, on average, they exercised with any of the FlexToBa exercise sessions over the course of the past 6 months. These data were collected immediately after physical function assessments.

Data Analytic Strategy

Preliminary analyses using t tests and chi-square analyses were conducted to determine whether there were any specific patterns to attrition at 6-month follow-up based on baseline demographics and level of function (ie, SPPB score). Next, we conducted analyses of variance to examine whether the two conditions maintained, improved, or declined in functional performance and functional limitations from the end of the intervention to 6-month follow-up. Finally, we conducted analyses of covariance to determine whether any effects at follow-up remained significant when controlling for age and sex. If effects attributable to the intervention were maintained 6 months following program termination, we would expect to see significant group differences in these analyses. Effect sizes are expressed as partial η² and a value of 0.04 is considered a practically meaningful effect (22).

Results

Attrition at Follow-Up

Of the 307 participants who entered the trial, 260 completed the intervention for 85% retention. From these 260, we were able to retain 237 (FlexToBa condition, n = 110; Healthy Aging condition, n = 127) for 6-month follow-up assessments. Analyses indicated that those who dropped out did not differ on any key baseline characteristics (eg, income, body mass index, gender, baseline function; all p’s > .30) other than current age (p = .05). Drop-outs (M _age = 72.17 years ± 6.02) were slightly older than those retained at 6-month follow-up (M _age = 70.63 years ± 4.76). Further analyses of dropout status across treatment condition for these variables were nonsignificant with the exception of education (p = .01) whereby those with more education in the FlexToBa condition were more likely to be retained at follow-up.

Functional Performance and Functional Limitations at Follow-Up

Table 1 shows the mean value and standard error followed by 95% confidence intervals for the FlexToBa condition and the Healthy Aging condition at the end of the intervention, at 6-month follow-up, and at 6-month follow-up adjusted for age and sex.

Table 1.

Intervention Effects on Follow-Up Functional Performance and Functional Limitations (mean ± SE, 95% confidence intervals)

	FlexToBa	Healthy Aging	p Value
SPPB
Postintervention	10.95±0.13 (10.69, 11.21)	10.40±0.12 (10.16, 10.63)	.002
6-mo follow-up	10.87±0.13 (10.60, 11.13)	10.39±0.12 (10.14, 10.63)	.01
6-mo follow-upadjusted	10.87±0.11 (10.66, 11.10)	10.46±0.10 (10.24, 10.67)	.04
Upper-body strength
Postintervention	15.01±0.38 (14.25, 15.77)	13.63±0.35 (12.93, 14.33)	.009
6-mo follow-up	15.86±0.41 (15.04, 16.68)	13.87±0.38 (13.12, 14.69)	.001
6-mo follow-upadjusted	15.66±0.40 (14.87, 16.45)	14.05±0.37 (13.29, 14.77)	.003
Upper-body flexibility
Postintervention	−2.87±0.46 (−3.77, −1.97)	−2.81±0.42 (−3.64, −1.98)	.90
6-mo follow-up	−2.56±0.47 (−3.48, −1.63)	−2.76±0.43 (−3.62, −1.91)	.74
6-mo follow-upadjusted	−2.49±0.44 (−3.35, −1.62)	−2.83±0.40 (−3.63, −2.03)	.56
Lower-body flexibility
Postintervention	−0.08±0.36 (−0.84, 0.69)	−0.98±0.39 (−1.69, −0.27)	.09
6-mo follow-up	0.66±0.38 (−0.09, 1.40)	0.02±0.37 (0.67, 0.70)	.21
6-mo follow-upadjusted	0.73±0.37 (0.02, 0.98)	−0.05±0.34 (−0.72, 0.62)	.12
Functional limitations*
Postintervention	65.41±0.67 (64.09, 66.72)	63.72±0.61 (62.50, 64.94)	.06
6-mo follow-up	64.58±0.69 (63.22, 65.94)	63.89±0.63 (62.63, 65.14)	.46
6-mo follow-upadjusted	64.13±0.64 (62.85, 65.40)	64.26±0.59 (63.09, 65.44)	.87

Notes: SPPB = Short Physical Performance Battery.

*Late-Life Function and Disability Instrument total score; post adjusted = adjusted for sex and age; 6-mo follow-up FlexToBa, n = 110; Healthy Aging, n = 127.

Short Physical Performance Battery

There was a statistically significant difference between groups for the SPPB values, F(1,226) = 9.49, p = .002, η² = 0.04, with the FlexToBa condition maintaining the intervention gains. This group difference remained significant after adjusting for covariates, F(1,224) = 6.20, p = .01, η² = 0.03. The magnitude of the difference between the intervention and control, 0.4, is a clinically meaningful difference (23).

Upper-body strength

Again, there was a significant group effect favoring the FlexToBa condition who completed more arm curls than the Healthy Aging condition, F(1,223) = 11.73, p = .001, η² = 0.05. This difference remained significant after adjusting for covariates, F(1,221) = 7.89, p = .005, η² = 0.03.

Flexibility

There was no significant group effect for lower body flexibility (ie, sit and reach task), F(1,223) = 3.71, p = .06, η² = 0.02, or between the two conditions for upper body flexibility (back scratch task), F(1,221) = 0.18, p = .68, η² = 0.00.

Functional limitations

There were no significant differences between conditions on reports of functional limitations, F(1,227) = 1.80, p = .18, η² = 0.00, without covariates or with covariates, F(1,225) = 0.19, p = .66, η² = 0.00.

Adherence to the FlexToBa Program

Compared to the end of the intervention, 46.4% of participants indicated being more physically active at 6-month follow-up, whereas 25.8% reported being just as physically active. In addition, 40.4% of those surveyed were still exercising with the DVD program three times per week as originally prescribed, whereas only 17.5% of the sample reported not using the DVD at follow-up. Overall, 82.5% of FlexToBa participants reported at least some degree of continued weekly participation with the program (ie, one or more days per week).

Discussion

Identifying methods for maintaining functional independence during aging is an important public health goal. We have recently reported on the efficacy of a 6-month, DVD-delivered exercise program for improving functional performance (ie, balance, mobility, strength, and flexibility) when compared to a Healthy Aging attentional control condition (9). In this study, we report data from a 6-month postintervention follow-up in the absence of any contact with or feedback to the participants. The primary outcome was the SPBB, a well-documented correlate of morbidity, mortality, and institutionalization in older adults, which is sensitive to change over time (11,12). Overall, participants in the FlexToBa condition retained postintervention improvements at 6-month follow-up, an effect that was both statistically significant and clinically meaningful (23,24). It might be argued that the effect size is small, however, based on the arguments of Ferguson (22), an effect size of η² = 0.04, is considered practically meaningful and should be considered in light of our primary outcome, the SPPB. The SPPB is an important clinical marker of subsequent morbidity, mortality, and institutionalization (11,12), and clinically significant improvements may have longer term benefits. In addition, these findings are encouraging given that our sample was relatively high functioning at entry into the trial. We might anticipate larger effects in those with more compromised function.

A report from one site of the Lifestyle Interventions and Independence for Elders Pilot trial examined the maintenance of functional performance (ie, SPPB) 24 months after completing a tapered, 12-month center to home-based exercise intervention (9). This intervention targeted older adults with compromised physical function and included aerobic activity, strength, balance, and flexibility exercises and also demonstrated maintenance effects in the SPPB at 24 months postintervention. Although the present intervention was shorter and assessed maintenance only at 12 months, that a clinically meaningful, if small, effect was maintained is encouraging. This might suggest the viability of the DVD-delivered exercise intervention as a useful and efficacious alternative and/or compliment to center-based interventions for those older adults desiring or transitioning to a home-based program. Moreover, demonstrating that such programs can preserve function in the nonfrail, as well as enhance compromised function, has considerable public health promise.

We further note maintenance effects for upper body strength favoring the DVD exercise program condition, an important component of everyday living, as it has implications for picking objects up, lowering them to the ground, or moving them. This might include play with grandchildren, working in the yard, or simply carrying out household tasks that are necessary for independent living. Performance on the assessment of upper-body flexibility remained unchanged from postintervention to follow-up in both conditions and did not significantly differ between groups. Similarly, although group differences in functional limitations approached significance at the end of the intervention period, significant differences were not present at follow-up.

These findings suggest that a home-based DVD-delivered intervention was successful at maintaining improvements in older adults’ physical function, 6 months beyond program termination and in the absence of any feedback or contact. Although newer, more interactive forms of technology are readily available, the production and sales of exercise DVDs continue to grow and these programs are typically well-received and regularly utilized by older adults (25). Evidence suggests that many older adults often prefer to exercise outside of a formal class for a myriad of reasons, from travel and accessibility to comfort and confidence (26). Thus, delivering a progressive exercise program via DVD provides a practical and acceptable alternative to traditional center-based approaches and, as a result, may be more generalizable than other programs aimed at increasing physical activity and improving physical function in this demographic. The FlexToBa program has the additional benefit of being a 6-month program with considerable variety in terms of difficulty and types of activities, enabling individuals of varying physical capabilities to be successful. This provides a potential antidote to the boredom that may be associated with the more typical commercially available DVDs, which rarely move beyond 40 minutes of content. In addition, DVD-delivered programs, such as FlexToBa, provide participants with continual access to a structured exercise routine, which may encourage long-term engagement in physical activity (27).

Continued participation rates at 6-month follow-up is encouraging, with ~70% of the intervention participants reporting current exercise levels to be equal to or greater than at intervention end and less than 20% reporting no DVD exercise-related activity. This is in contrast to maintenance rates following cessation of center-based structured interventions where the professionally dispensed, socially supportive programs are withdrawn somewhat abruptly leaving participants to become independent exercisers. Although this latter status is a lofty public health goal, the sudden withdrawal of resources and support more often than not results in relapse (28). The innovative approach of delivering physical activity in a progressive and structured way via DVD actually encourages older adults to be independent exercisers from the start of the program. Such features resulted in relatively good activity maintenance and, as importantly, maintenance of intervention gains in physical function. These components bode well for the potential scalability of this program.

This study has a number of strengths. The approach of delivering an exercise program via DVD was well-received by this sample and has considerable implications in terms of reaching those older adults who may be in most need of exercise programs but have limited access to them. Moreover, the FlexToBa DVD program includes several components that are not necessarily included in other commercially available exercise DVDs for older adults. For example, the exercise program incorporates behavior change principles based in social cognitive theory, with a focus on mastery experiences and goal-setting (29). The FlexToBa program contains six progressive exercise sessions that are designed to be completed over a 6-month period. Exercises presented within the earlier session begin with basic movements and ultimately increase in complexity and physical challenge during the later sessions. In addition, two modifications (ie, simpler and more challenging versions) are provided for all of the exercises to allow for progression within each session and to better meet varying levels physical abilities. Importantly, we report that functional performance improvements were clinically meaningful following the intervention and maintained 12 months beyond baseline. Most studies examining the effects of an exercise program on physical function assess the immediate effects at program end and seldom conduct follow-up assessments. Finally, we note a relatively low rate of attrition at follow-up.

In spite of these strengths, the majority of our sample was white, female, well-educated, and relatively healthy. Although similar findings would be apparent in other samples of older adults, including ethnic minorities, lower SES groups, and those with chronic conditions, are not known. We did not assess the types of activity that the participants engaged in during the follow-up period. Consequently, we are unable to determine whether participants may have taken up new activities, such as walking, which may have contributed to the preservation of function. Furthermore, the higher rate of attrition in the exercise condition at follow-up for older participants might constitute a bias with younger participants tolerating the treatment better. However, given the mean difference was only 2 years in age, further examination of this perspective is warranted. Future attempts to assess maintenance effects of physical activity programs in older adults should identify additional strategies to retain those in the upper range of the age spectrum.

Delivering an exercise program via DVD can assist in meeting the personal needs, values, and preferences of older adults, and may better promote an active lifestyle which, as a result, can lead to improvements in physical function. Whether similar program delivery via other multimedia platforms (eg, podcasts, social media, mobile applications) would be as effective in the maintenance of physical function in older adults remains to be determined. Further examination of the FlexToBa program’s effectiveness could be demonstrated by comparing the effects of the program as originally delivered (ie, DVD plus titrated support calls, plus monthly feedback of progress) to the provision of the DVD alone. In addition, the inclusion of and access to various modes of behavioral support (eg, website companion, text messaging, social media, continued phone support) following program termination should be considered in future studies as they may enhance maintenance effects. Finally, determining the efficacy of the FlexToBa program in individuals with chronic disease conditions which compromise mobility and function (eg, multiple sclerosis) is also warranted. In closing, we remain optimistic that the FlexToBa program can be an innovative, effective, and well-tolerated vehicle for delivering exercise content designed to improve physical function and maintain independent living in older adults.

Funding

The work was supported by the National Institute on Aging at the National Institutes of Health (2R01 AG20118).