Secondary Logo

Journal Logo

Systematic Review

Exercise for Nonagenarians: A Systematic Review

Miller, Kyle J. BPsych1; Suárez-Iglesias, David PhD2; Varela, Silvia PhD3,4; Rodríguez, David BPEd4; Ayán, Carlos PhD4,5

Author Information
Journal of Geriatric Physical Therapy: October/December 2020 - Volume 43 - Issue 4 - p 208-218
doi: 10.1519/JPT.0000000000000245
  • Free

Abstract

INTRODUCTION

Physical exercise has been recognized as an important health strategy to promote successful aging, since it can further enhance the functioning of older adults who are already characterized as aging normally.1 Maintenance of physical functioning and independence is a key attribute of successful aging.2,3 Given that physical independence is typically associated with higher levels of physical fitness, older people are encouraged to regularly participate in physical exercise training programs. This strategy can help older adults continue to be independent until the end of their lifespan.4

When it comes to prescribing physical exercise for older age, nonagenarians are often overlooked and represent a population of significant interest. In comparison with older people of younger age, nonagenarians tend to participate in reduced levels of physical activity, which leads to poorer functional independence.5 Thus, it seems that the performance of physical exercise is especially important in this age group.6

Exercise prescription for the oldest old needs to be carefully tailored and individualized with the specific objectives of the person or group in mind.7 In relation to this, it is important to note that although there are numerous studies that have described the characteristics and effects of exercise training programs on older adults, most studies have been conducted on people younger than 90 years. Consequently, scientific evidence directly investigating the effects of exercise prescription on nonagenarians is scarce.

In light of this limitation, it is important to identify the basic exercise prescription guidelines for people older than 90 years by scrutinizing the key studies that have provided evidence on the effects of exercise training among nonagenarians. This can be achieved by conducting systematic reviews that synthesize and summarize the scientific evidence on this topic. Thus, the purpose of this study was to conduct a systematic review to identify the characteristics and methodological quality of investigations that have examined the effects of physical exercise on nonagenarian cohorts. It is anticipated that the obtained findings will provide information of relevance that will allow clinicians and researchers to establish basic guidelines for effective physical exercise intervention and prescription in this population.

METHODS

This systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The selected search strategy and methods of analysis were registered in the PROSPERO database (ref: CRD42018112642).

Search Strategy

Five electronic databases (the MEDLINE/PubMed, CINAHL, Scopus, SPORTDiscus, and Cochrane Library) were searched systematically from their inception until June 2018. A secondary search was performed in November 2018 to update the initial search. The following search terms, Boolean operators, and combinations were used: “nonagenarians” OR “centenarians” OR “oldest old” AND “exercise” OR “physical activity.”

Eligibility Criteria

Intervention studies that provided information regarding the effects of exercise on people 90 years or older were considered eligible. Although randomized controlled trials (RCTs) provide the highest quality of scientific evidence, the search also included non-RCT designs, due to the following reasons. First, if the number of RCTs analyzing nonpharmacological therapies is scarce, it is advisable to include non-RCTs to gain a better overview of the available evidence.8,9 Second, when reviewing the feasibility of novel therapies, non-RCTs are useful to inform safety, potential adverse effects, and response rates,10 which are of special interest in frail and older populations.

Investigations were excluded if (a) the exercise group included people younger than 90 years, unless separate data were available for the nonagenarian subgroup; (b) the intervention was based on the performance of a single exercise training session; (c) the full text of the study was not available; or (d) the study was not written in English or Spanish.

Study Selection

Two researchers independently screened the titles and abstracts of the identified studies for eligibility, and discrepancies were resolved by consensus with a third researcher. Once an agreement had been reached, a full-text copy of all potentially relevant studies was obtained. Full-text articles were initially sought from journal websites or ordered through the university's interlibrary loan system. If it was not available, then an email was sent to the corresponding author. If it was unclear whether the study met the selection criteria, advice was sought from a third researcher and an agreement was reached.

Data Extraction

Information on participants' characteristics, exercise program, adverse events, attrition rates, and outcomes was extracted from the records by one researcher and validated by a second investigator. Missing data were obtained from the corresponding author, whenever possible.

Quality Appraisal

Studies were evaluated using 2 quality appraisal tools. The methodological quality of the selected RCTs was directly retrieved from the Physiotherapy Evidence Database (PEDro). The quality appraisal of RCTs not rated in the PEDro was independently performed by 2 researchers, with discrepancies in ratings arbitrated by a third researcher. The suggested cut-off scores to categorize studies by quality were excellent (9-10), good (6-8), fair (4-5), and poor (≤3).11

The methodological quality of the noncontrolled studies was assessed by 2 researchers independently using the Quality Assessment Tool for Before-After Studies with No Control Group.12 This tool includes 12 criteria for evaluating the internal validity of a research design. Researchers must evaluate the quality of each study's design (“good,” “fair,” or “poor”) in accordance with how much risk of bias they detect. In case of disagreement, advice was sought from a third researcher. Similarly, the 14-item Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies12 was used to assess the methodological quality of the retrospective investigations. After independently reviewing the methodological quality of the selected studies, Cohen's κ coefficient was calculated to evaluate overall agreement between reviewers.

Evidence Synthesis

Data were analyzed using Stata Software version 15.1.13 When at least 2 studies reported pre- and posttreatment data on homogeneous outcome measures, within-group analyses were presented in forest plots.14 The standardized mean differences (SMDs) and their 95% confidence interval (CI) were calculated to assess the change in the exercise groups comparing pretreatment versus posttreatment results for each selected variable. If heterogeneity between outcome measures prevented pooling of effect size data, a descriptive analysis was reported.

To obtain the pooled effects, a fixed-effect model and a random-effects model were performed, selecting the most adequate model for each analysis according to the heterogeneity level, according to DerSimonian and Laird (random-effects model if I2 > 30%).15 SMDs were considered significant when their 95% CIs excluded 0, while pooled SMD values were interpreted according to Cohen,16 whereby effects were considered small (0.2), medium (0.5), and large (0.8). Positive effect sizes were indicative of the exercise intervention having a positive posttreatment effect on the specified outcome measure. Authors were contacted if additional information was required for effect size calculations.

RESULTS

From an initial 460 records, a total of 7 studies were included in the systematic review (see Figure 1). The methodological designs of the included studies composed of 3 RCTs, 1 retrospective study, 2 case reports, and 1 single-subject A-B design. Notably, RCTs by Serra-Rexach et al17 and Ruiz et al18 reported the same trial and participant data.

F1
Figure 1.:
Flowchart of screening process.

Characteristics of Included Studies

Full information regarding the participants' characteristics, intervention programs, feasibility outcomes (adherence, attrition, and adverse effects), and main findings from each study are summarized in Table 1.

Table 1. - Characteristics of the Studies Included in This Review
Authors Study Design Participants Intervention Variables Results
Cadore et al19 RCT Sample:
n = 39 pre, 24 post (70.83% women)
Distribution, mean age (SD); sex:
IG: n = 11, 93.4 (3.2) y
CG: n = 13, 90.1 (1.1) y
Living status: Institutionalized
Duration: 12 wk
IG: Balance exercises + upper and lower body resistance exercises, 40-min sessions with 8-10 repetitions for exercise performed at 40%-60% 1RM and high velocity of motion, in 2 nonconsecutive d/wk
CG: Mobility and stretching exercises, 30 min/d and 4 d/wk
•Gait velocity (m/s)
• Gait velocity verbal task (m/s)
• Gait velocity arithmetic task (m/s)
• TUG
• TUG verbal task
• TUG arithmetic task
• Raise from a chair
• Balance
• Barthel Index deterioration
• Handgrip (N)
• Hip flexion strength (N)
• Knee extension strength (N)
• Upper body 1RM (kg)
• Lower body 1RM (kg)
• Maximal power at 30% 1RM (W)
• Maximal power at 60% 1RM (W)
• Falls incidence
• Cognitive score (arithmetic)
• Cognitive score (verbal)
• Cognitive score (TUG arithmetic)
• Cognitive score (TUG verbal)
Recruitment: 82.05% (32 out of 39)
Completion rate:
IG: 68.75% (11 out of 16)
CG: 81.25% (13 out of 16)
Adherence: >90% in all the sample
Adverse effects: NR
Significant differences (P < .05):
Intragroup (pre vs post)
↑ TUG: IG
↑ TUG verbal task: IG
↑ Raise from a chair: IG
↑ Gait velocity: CG
↑ Gait velocity arithmetic task (m/s): CG
↑ Gait velocity verbal task (m/s): CG
↑ Handgrip (N): CG
↑ Hip flexion strength (N): IG
↑ Knee extension strength (N): IG, CG
↑ Upper body 1RM (kg): IG
↑ Lower body 1RM (kg): IG
↑ Maximal power at 30% 1RM (W): IG
↑ Maximal power at 60% 1RM (W): IG
↓ Falls incidence: IG
Intergroup (pre): NR
Intergroup (post):
Lower falls incidence: IG < CG
Less time in TUG verbal task: IG < CG
Lower Barthel Index deterioration: IG < CG
Higher hip flexion strength (N): IG > CG
Higher knee extension strength (N): IG > CG
Serra-Rexach et al17 RCT Sample:
n = 40 pre, 38 post
Distribution, mean age (SD); sex:
IG: n = 19, 92 (2) y; 78.94% women
CG: n = 19, 92 (2) y; 78.94% women
Living status: Nursing home residents
Duration: 8 wk
IG: 45- to 50-min sessions composed of aerobic exercise (5-15 min) performed at 12-13 on Borg RPE Scale followed by 2-3 sets of upper and lower body resistance exercises performing 8-10 repetitions, 1-2 min of rest in between, and 1 set of minor muscle groups, progressing from 30% 1RM at the start of the program to the 70% 1RM at the end (weekly load increase of 5% 1RM), performed 3 nonconsecutive d/wk + 5 d/wk of mobility exercises
CG: Mobility exercises in 40- to 45-min sessions 5 d/wk
• 1RM leg press (kg)
• Handgrip strength (kg) (dynamometer)
• 8-m walk test
• 4-step stairs test
• TUG
• Number of falls
Recruitment: 61.53% (40 out of 65)
Completion rate:
IG: 95% (19 out of 20)
CG: 95% (19 out of 20)
Adherence: 74 ± 6% IG
Adverse effects: One patient suffered transient lower back pain at the start of a training program. Some patients complained of mild muscle pain associated with the leg press exercises.
Significant differences (P < .05):
Intragroup (pre vs post)
↑ 1RM leg press (kg): IG
Intergroup (pre): NR
Intergroup (post):
Higher 1 RM leg press (kg): IG > CG
Lower number of falls: IG < CG
Ruiz et al18 RCT Sample:
n = 40
Distribution, mean age (SD); sex:
IG: n = 20, 92.3 (2.3) y; 80% women
CG: n = 20, 92.1 (2.3) y; 80% women
Living status: Nursing home residents
Duration: 8 wk
IG: 45- to 50-min sessions composed of aerobic exercise (5-15 min) performed at 10-12 on Borg RPE Scale followed by 2-3 sets of lower body resistance exercises performing 8-10 repetitions, 1-2 min of rest in between, and 1 set of minor muscle groups of both upper and lower body, progressing from 30% 1RM at the start of the program to the 70% 1RM at the end (weekly load increase of 5% 1RM), performed 3 nonconsecutive d/wk + 5 d/wk of mobility exercises
CG: Mobility exercises 5 d/wk
• Angiotensin-converting enzyme (ng/mL)
• Soluble amyloid precursor protein (ng/mL)
• Brain-derived neural factor (pg/mL)
• Epidermal growth factor (pg/mL)
• Tumor necrosis factor alpha (pg/mL)
Recruitment: CD
Completion rate:
IG: 100%
CG: 100%
Adherence: 74 ± 6% IG
Adverse effects: NR
Significant differences (P < .05): Not found
Torpilliesi et al21 Retrospective study Sample:
n = 76 pre, 71 post
Distribution, mean age (SD); sex:
IG: n = 71, 93.2 (2.5 y); 84.2% women
Living status: Outpatients
Duration: 6 d, between admission and discharge following hip fracture surgery
Rehabilitation program composed of strengthening, transfers, postural and gait training, performed in 2 sessions per day of 40 min from Monday to Friday and 1 session on Saturday. Interruptions of no more than 1 min were allowed when the patient needed to rest
• Barthel Index
• Tinetti Score
• Gait ability (% of patients in grades 1, 2, 3, and 4)
Recruitment: CD
Completion rate: 93.42% (71 out of 78)
Adherence: NR
Adverse effects: NR
Significant differences (P < .05):
Intragroup (pre vs post)
↑ Barthel Index
↑ Transferring subitem of Barthel Index
↑ Walking subitem of Barthel Index
↑ Tinetti Score
↑ Gait ability
Idland et al20 Single subject A-B Sample:
n = 8 pre, 6 post
Distribution, mean age (SD); sex:
IG: n = 6, 91.33 (1.36) y; 100% women
Living status: Community dwelling
Duration: 12 wk
45- to 60-min resistance training sessions of the upper and lower body main muscle groups, 4 exercises performed for 8-12 RM, quickly in the concentric and slower in the eccentric phase of the contraction, for 2-3 sets, 2 d/wk
• TUG (s)
• Comfortable walking speed test in 6 m (s)
• 30-s chair stands
Recruitment: 8 of 27 (29.62%)
Completion rate: 75% (6 out of 8)
Adherence: 57%-96%
Adverse effects: One participant reported an episode of cardiac arrhythmia and another reported transient muscle soreness
Significant differences (P < .05): Not analyzed
Trends toward improvement
All of the participants improved in the TUG
Four of 6 improved in the 30-s chair stands
Silsupadol et al23 Case report Sample: n = 2
Distribution (age; sex):
Patient 1: 90 y; female
Patient 2: 93 y; female
Living status: Independent
Duration: 4 wk
Patient 2: 45-min sessions of dual-task balance training under a fixed-priority instructional set, 3 d/wk
Patient 3: 45-min sessions of dual-task balance training under a variable-priority instructional set, 3 d/wk
• TUG (s) under single-task condition
• TUG (s) under dual-task condition
• Berg Balance Scale
• Dynamic Gait Index
• Activities-specific Balance Confidence Scale
• Number of counted backward by “threes” over 5 trials performed simultaneously with narrow walking
• Number of counted backward by “threes” over 5 trials performed simultaneously with an obstacle crossing
Recruitment: CD
Completion rate: 100%
Adherence: NR
Adverse effects: NR
Significant differences (P < .05): Not analyzed
Trends toward improvement
Both improved in the Berg Balance Scale
Both improved the Activities-specific Balance Confidence Scale
Both improved in the TUG in single- and dual-task conditions
Both improved in the Dynamic Gait Index
Gaub et al22 Case report Sample: A 101-y-old woman
Living status: Family-dwelling
Duration: 36 wk
12 weeks of balance and flexibility intervention, 36 sessions, 60-min 3 d/wk including balance, speed of reaction, and flexibility exercises
24 wk of seated strengthening exercises in group classes, in 30-min sessions, 3 d/wk
Functional status (physical performance tests)
  • Book lift

  • Don/doff laboratory coat

  • Pick up nickel

  • 500 ft walk

  • Stair climb-1 flight

  • Chair rise

  • Stairs of flights

  • 360° turn

  • Standing balance

• Berg Balance Scale
Recruitment: NA
Completion rate: NA
Adherence: NR
Adverse effects: NR
Significant differences (P < .05): Not analyzed
Trends toward improvement
After 12 wk:
↑ Score in the physical performance test (better ability to climb a flight of stairs, control a 360° turn and balance in standing)
• Sensation of the toes
• Speed of reaction
• Exercise capacity (6-min walking test)
• Gait speed in 15m
• Range of motion of the ankle, knee, and hip
• Perceived quality of life (SF-36)
• Knee extension strength (isokinetic handheld dynamometry)
• Knee flexion strength (isokinetic handheld dynamometry)
↑ Berg Balance Scale score (global)
↑ Speed of reaction, but minimal change
↑ Distance in 6-min walking test
↓ Time to walk 15 m
↓ Self-perceived quality of life
After 24 wk:
↓ Score in the physical performance test
↓ Berg Balance Scale score (standing balance)
↑ Berg Balance Scale score (sit-to-stand transition)
↓ Distance in 6-min walking test
↑ Time to walk 15 m
↑ Perceived quality of life
↑ Knee flexion/extension strength measures
After 36 wk:
↓ Score in the physical performance test, without reaching the preintervention score
↓ Distance in 6-min walking test, without reaching the preintervention score
↑ Time to walk 15 m
Abbreviations: CD, cannot determined; CG, control group; IG, intervention group; NA, not applicable; NR, not reported; 1RM, 1-repetition maximum; RCT, randomized controlled trial; RPE, rating of perceived exertion; SF-36, 36-item Short-Form Health Survey; TUG, Timed Up and Go.

Participants

Participants in the included studies were nonagenarians who were described as frail institutionalized,19 community-dwelling,20 nursing home residents,17,21 living with family,22 and independent.23

Interventions

Three studies conducted a mixed muscular strength program, with the addition of either balance and gait19,21 training or aerobic exercise.17 Two studies focused primarily on balance training,22,23 while one study exclusively focused on muscular strengthening.20 The duration of the interventions ranged from 6 days21 to 36 weeks.22 Sessions lasted for a duration of 40 to 60 minutes, and frequency was between 2 and 6 sessions per week.

Adherence, Attrition, and Adverse Events

Adherence to the exercise sessions was reported in 4 studies17–20 and ranged from 57%20 to more than 90%.19 Attrition rate was also reported in 4 studies.17,19–21 Finally, 2 studies reported the presence of adverse events. In one study,20 a participant reported an episode of cardiovascular symptoms and another reported transient muscle soreness. In the second study,17 a participant suffered transient lower back pain at the start of training, while other participants complained of mild muscle pain associated with leg press exercises. No other major or minor adverse events were reported.

Quality Appraisal

The methodological quality of the studies included in the systematic review is outlined in Table 2. The methodological quality of the RCTs was good.17–19 Single-subject and case report designs ranged from moderate20,22 to poor quality.23 The methodological quality of the retrospective study was moderate.21 The interrater agreement (Cohen's κ) between reviewers was 0.80.

Table 2. - Quality Assessmenta
PEDro Scale 1 2 3 4 5 6 7 8 9 10 11 Total
Cadore et al19 Yb Y Y Y N N Y N N Y Y 6/10
Ruiz et al18 Yb Y N Y N N Y Y Y Y Y 7/10
Serra-Rexach et al17 Yb Y Y Y N N Y Y Y N Y 7/10
NHLBI Pre-Post Tool 1 2 3 4 5 6 7 8 9 10 11 12 Total
Gaub et al22 Y NR N CD N Y Y Y Y Y N NAb 6/11
Idland et al20 Y Y Y N N Y Y N Y Y Y NAb 8/11
Silsupadol et al23 Y NR N CD N CD Y N Y Y N NAb 4/11
NHLBI Observational Cohort Tool 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Total
Torpilliesi et al21 Y Y Y N N Y N N Y N N CD Y Y 7/14
Abbreviations: CD, cannot determine; N, no; NA, not applicable; NR, not reported; Y, yes.
aPEDro scale scores are interpreted as excellent (9-10), good (6-8), fair (4-5), or poor (≤3). NHLBI tools do not have specific cut-off scores, but are tentatively interpreted as poor, fair, or good.
bNot included in total score.

Primary Outcomes

Gait

Six studies analyzed the effects of the interventions on gait-related outcomes.17,19–23 A statistically significant difference was observed between pre- and posttreatment intervention outcomes in 5 studies,19–23 whereas the Serra-Rexach et al17 did not report a difference.

Muscular strength

Out of the 4 studies that assessed the effects of an exercise intervention on muscular strength parameters,17,19,20,22 2 found significant changes in this outcome. Significant improvements were reported in the muscular strength of participants' upper and lower body after a twice-weekly, 12-week multicomponent exercise program composed of muscle power training (8-10 repetitions, 40%-60% of the 1-repetition maximum) combined with balance and gait retraining.19 In addition, an 8-week intervention focused on lower limb strength exercises of light to moderate intensity contributed to a significant improvement in participants' lower body muscular strength.17

Balance

Four studies included balance as an outcome measure,19,21–23 with significant improvements reported in 2 of them. On the one hand, the multicomponent exercise intervention used by Cadore et al19 resulted in significantly increased balance. On the other hand, Torpilliesi et al21 demonstrated that participants undergoing a standardized rehabilitation treatment composed of strengthening exercises, transfers, postural and gait training, and adaptive equipment training (40-minute sessions twice a day from Monday to Friday, and 1 session on Saturday) had a significantly enhanced balance between on admission and at discharge after hip fracture surgery.

Fall incidence

The effect of the intervention on fall incidence was analyzed in 2 studies.17,19 After 12 weeks of multicomponent exercise, this parameter not only experienced a significant reduction in the intervention group, but was also significantly lower in the intervention group compared with the control group.19 Similarly, over their study period (intervention + detraining), Serra-Rexach et al17 reported that the number of falls per participant was 1.2 times significantly lower in the intervention than in the control group.

Functional independence

Two studies19,21 analyzed the impact of the interventions on outcomes related to the functional independence of the participants, with both reporting significant improvements in this parameter.

Other outcomes

Exercise did not have a significant impact on cognition and related serum biochemical markers.18 The effect of exercise on sensation in the toes, speed reaction, exercise capacity, range of motion, and perceived quality of life was examined in one study.22 An improvement was observed in all parameters except for sensation in the toes, although no significance analysis was performed due to the nature of the study design.

Evidence Synthesis

Data from a total of 37 participants across the 3 RCTs with pre- and posttreatment data were pooled in the analysis. Adequate effect size data were available for 5 outcome measures: gait speed, Timed Up and Go (TUG) test, 30-second chair stand (30SCS) test, 1-repetition maximum (1RM) leg press, and handgrip strength. The information provided in the studies by Gaub et al22 and Silsupadol et al23 was not included in the analysis, since an effect size could not be calculated using data from fewer than 3 cases. The pooled analysis included all the outcome measurements related to lower body functioning, which were reported as the SMD for each variable and the pooled estimates. Full analyses can be found in Figure 2.

F2
Figure 2.:
Forest plot displaying the fixed-effect (I+V) and random-effects (D+L) meta-analysis of exercise intervention effects on lower body physical function of nonagenarians. Squares represent the effect size estimate (standardized mean difference, SMD) and horizontal lines represent the confidence intervals for each study. Diamonds represent the effect size estimates for subgroups and the overall effect. The vertical line represents the null hypothesis (SMD = 0). The vertical dotted line represents the overall mean difference from all studies. A positive SMD is indicative of postintervention improvement in lower body physical function.

When assessing the impact of exercise programs on the lower body physical functioning of nonagenarians, the pooled analyses of the interventions showed significant improvements in the 30SCS (SMD = 0.74; 95% CI = 0.03, 1.44; P < .05) and in 1RM leg press (SMD = 1.51; 95% CI = −0.84, 3.86; P < .01), but not in the gait speed (SMD = 0.35; 95% CI = −0.11, 0.81; P = .137) or the TUG test (SMD = −0.02; 95% CI = −0.48, 0.44; P = .935). The overall pooled results showed a significant improvement in global lower body functioning (SMD = 0.47; 95% CI = 0.04, 0.90; P < .01).

Two RCTs17,19 reported no significant differences between pre- and posttreatment handgrip strength. This persisted even when effect sizes were pooled, with a pooled SMD = 0.07 (95% CI = −0.43, 0.57); I2 = 0.0%; P = .78, indicating that exercise did not significantly improve handgrip strength (kg) in nonagenarians.

DISCUSSION

This study aimed to perform a search systematically in the current literature, identifying key characteristics, and scrutinizing the methodological quality of investigations that have examined the effects of physical exercise on nonagenarians. To achieve this objective with the maximum accuracy, we opted to include all experimental study designs rather than only focusing on RCTs. Thus, the spectrum of the results was broader, and in this sense, the data and conclusions drawn from this review can provide greater clarity around the issues at hand.

Despite the small number of investigations that were analyzed in this review, most included studies displayed acceptable methodological quality. This indicates that, although the existing scientific evidence is scarce, valuable information is still available to allow clinicians and researchers to determine whether this population can safely and effectively take part in exercise programs specifically designed for those regarded as the oldest age group.

Interestingly, the completion rate reported from the studies was generally high and only 2 individuals, representing around 1% of the total sample included in the review, reported adverse events. Therefore, it can be speculated that people older than 90 years can safely perform some types of physical exercise. Related to this, a second aspect of crucial interest is the potential benefits that this age group can gain from participating in these exercise interventions. Significant improvements were found in gait, muscular strength, balance, and fall incidence. These variables are strongly related to functional independence, which is typically poorer in nonagenarians than in other age groups.24 It is important to note, however, that these significant effects were not reported in all the studies that included these variables as outcome measures. For instance, only half of the investigations that tested the effects of exercise on muscular strength and/or balance reported significant improvements. Therefore, more research is needed before reliable conclusions can be drawn.

In the present systematic review, when more than 2 studies analyzed the same outcome measure, within-group analyses were calculated with a weighted mean difference (95% CI) and presented as a forest plot. This allowed independent results from several studies to be combined on a standardized scale of measurement, accounting for the variation in sample size and dispersion in effect sizes. Thus, rather than examining findings individually, similar studies were pooled together so that more precise conclusions can be made about the results and heterogeneity can be evaluated across a diverse range of nonagenarian cohorts.

The pooled results of 2 RCTs17,19 and 1 single-subject A-B design20 demonstrated a significant improvement in lower body functioning, validating the results of the individual studies. These findings are of importance, since lower body functioning is a significant factor in the prevention of falling and maintenance of independent gait.25,26 Therefore, it is conceivable that physical exercise could be used to maintain lower body mobility and reduce the natural decline of physical functioning typically associated with aging. This highlights the need for further experimental research.

Another finding of this review is the lack of scientific evidence regarding the effects of aerobic training programs on nonagenarians, since only one of the selected studies included aerobic exercise as part of a combined intervention modality. This is a remarkable fact that should be considered in future studies, given that this exercise modality has been shown to have a positive impact on important age-related health factors, including fall risk and cognitive decline.27,28

Similarly, although exercise has been shown to improve cognition in older adults due to several neurophysiological responses (ie, increase of peripheral brain-derived neurotrophic factor [BDNF], greater production of insulin-like growth factor, or exercise-induced synaptogenesis, among others),28 only one of the studies included in this review tested cognitive functioning as an outcome measure. The absence of significant effects observed in this research was explained based on a lack of a stimulating effect of resistance training on basal BDNF.

In summary, the findings of this review indicate that exercise, particularly interventions integrating a combination of muscular resistance and balance/gait-related tasks, is a feasible therapy for nonagenarians, which can reduce the impact of the natural process of deterioration associated with aging. This information is of particular interest for health professionals who want to prescribe physical exercise to older people and researchers who wish to further the understanding of exercise as an intervention against age-related deterioration in nonagenarians.

Limitations

There are several limitations that need to be considered to accurately interpret the data shown here. First, the samples were small in all included studies and authors did not report whether the requisite of 80% power for the selected sample size was met, which may have increased the chance of type II errors. Second, despite the benefits of including a mixture of methodological designs in the 1 review (as previously mentioned), the results extracted from high-quality research designs such as RCTs were not directly comparable to those of studies with no control groups or case report studies. Related to this, only pre- and posttreatment data from the exercise groups were included in the quantitative analysis. This was due to the low number of studies incorporating comparable control groups. Finally, there are certain methodological limitations inherent to the review design, such as language restrictions, possible publication bias, or not having reviewed gray literature.

CONCLUSIONS

Exercise is a feasible therapy for nonagenarians that can lead to improved physical functioning and subjective well-being. Future research should focus on the effects of aerobic interventions, as well as on the impact that exercise has on the cognitive level of this population.

REFERENCES

1. Harmell AL, Jeste D, Depp C. Strategies for successful aging: a research update. Curr Psychiatry Rep. 2014;6(10):476.
2. Ayers E, Barzilai N, Crandall JP, Milman S, Verghese J. Association of exceptional parental longevity and physical function in aging. Age. 2014;36(4):9677.
3. Gopinath B, Kifley A, Flood VM, Mitchell P. Physical activity as a determinant of successful aging over ten years. Sci Rep. 2018;8(1):10522.
4. Garatachea N, Pareja-Galeano H, Sanchis-Gomar F, et al. Exercise attenuates the major hallmarks of aging. Rejuvenation Res. 2015;18(1):57–89.
5. Frisard MI, Fabre JM, Russell RD, et al. Physical activity level and physical functionality in nonagenarians compared to individuals aged 60-74 years. J Gerontol A Biol Sci Med Sci. 2007;62(7):783–788.
6. Fabre JM, Wood RH, Cherry KE, et al. Age-related deterioration in flexibility is associated with health-related quality of life in nonagenarians. J Geriatr Phys Ther. 2007;30(1):16–22.
7. Viña J, Borras C, Sanchis-Gomar F, et al. Pharmacological properties of physical exercise in the elderly. Curr Pharm Des. 2014;20(18):3019–3029.
8. Linde K, Scholz M, Melchart D, Willich SN. Should systematic reviews include non-randomized and uncontrolled studies? The case of acupuncture for chronic headache. J Clin Epidemiol. 2002;55(1):77–85.
9. Reeves BC, Deeks JJ, Higgins JPT, Wells GA. Including non-randomized studies. In: Higgins JPT, Green S, eds. Cochrane Handbook for Systematic Reviews of Interventions. Version 5.1.0. Oxford, UK: The Cochrane Collaboration; 2011.
10. Peinemann F, Tushabe DA, Kleijnen J. Using multiple types of studies in systematic reviews of health care interventions—a systematic review. PLoS One. 2013;8(12):e85035.
11. Foley NC, Teasell RW, Bhogal SK, Speechley MR. Stroke rehabilitation evidence-based review: methodology. Top Stroke Rehabil. 2003;10(1):1–7.
12. National Heart Lung and Blood Institute. Quality assessment tool for before-after (pre-post) studies with no control group. https://www.nhlbi.nih.gov/health-topics/study-quality-assessment-tools. Accessed November 11, 2018.
13. StataCorp. Stata Statistical Software: Release 15. College Station, TX: StataCorp LLC:2017.
14. Valentine JC, Pigott TD, Rothstein HR. How many studies do you need? A primer on statistical power for meta-analysis. J Educ Behav Stat. 2010;35(2):215–247.
15. DerSimonian R, Laird N. Meta-analysis in clinical trials. Control Clin Trials. 1986;7(3):177–188.
16. Cohen J. Statistical Power Analysis for the Behavioral Sciences. 2nd ed. Hillsdale, NJ: Lawrence Erlbaum Associates; 1988.
17. Serra-Rexach JA, Bustamante-Ara N, Hierro Villarán M, et al. Short-term, light- to moderate-intensity exercise training improves leg muscle strength in the oldest old: a randomized controlled trial. J Am Geriatr Soc. 2011;59(4):594–602.
18. Ruiz JR, Gil-Bea F, Bustamante-Ara N, et al. Resistance training does not have an effect on cognition or related serum biomarkers in nonagenarians: a randomized controlled trial. Int J Sports Med. 2015;36(1):54–60.
19. Cadore EL, Moneo AB, Mensat MM, et al. Positive effects of resistance training in frail elderly patients with dementia after long-term physical restraint. Age. 2014;36(2):801–811.
20. Idland G, Sylliaas H, Mengshoel AM, Pettersen R, Bergland A. Progressive resistance training for community-dwelling women aged 90 or older: a single-subject experimental design. Disabil Rehabil. 2014;36(15):1240–1248.
21. Torpilliesi T, Bellelli G, Morghen S, et al. Outcomes of nonagenarian patients after rehabilitation following hip fracture surgery. J Am Med Dir Assoc. 2012;13(1):81.e1–e5.
22. Gaub MG, Prost E, Bomar M, Farid R, Langland G, Brown M. Efficacy of balance and flexibility intervention in a frail female centenarian. J Geriatr Phys Ther. 2004;27(1):22–28.
23. Silsupadol P, Siu K, Shumway-Cook A, Woollacott MH. Training of balance under single- and dual-task conditions in older adults with balance impairment. Phys Ther. 2006;86(2):269–281.
24. Bohannon RW. Reference values for the Timed Up and Go test: a descriptive meta-analysis. J Geriatr Phys Ther. 2006;29(2):64–68.
25. Chang JT, Morton SC, Rubenstein LZ, et al. Interventions for the prevention of falls in older adults: Systematic review and meta-analysis of randomised clinical trials. BMJ. 2004;328(7441):680.
26. Sherrington C, Tiedemann A, Fairhall N, Close JC, Lord SR. Exercise to prevent falls in older adults: an updated meta-analysis and best practice recommendations. N S W Public Health Bull. 2011;22(3/4):78–83.
27. Chase JD, Phillips LJ, Brown M. Physical activity intervention effects on physical function among community-dwelling older adults: a systematic review and meta-analysis. J Aging Phys Act. 2017;25(1):149–170.
28. Bherer L, Erickson KI, Liu-Ambrose T. A review of the effects of physical activity and exercise on cognitive and brain functions in older adults. J Aging Res. 2013;2013:657508.
Keywords:

aging; exercise; oldest old; physical activity; physical functioning

© 2019 Academy of Geriatric Physical Therapy, APTA.