Table 2.
Characteristics of the included studies
| Reference | Sample | Setting | Identification of frailty | Intervention characteristics | Outcome measures | Findings (Cohen’s d) |
|---|---|---|---|---|---|---|
| Binder 2005 [38] | n = 91 from the USA Age, mean ± SD: 83.0 ± 4.0 54 % women | Community dwelling | Screening instruments and procedures [12]: Modified Physical Performance Test score between 18 and 32 (maximum 36); reporting the difficulty and/or assistance with up to two instrumental and/or one basic ADL; and a peak aerobic power between 10 and 18 mL kg-1 min-1 | Multi-component PRT 9 months 3/week 60-90 min/session Initial goal: 1-2 sets 6-8 repetitions 65% 1-RM Final goal: 3 sets 8-12 repetitions 40-60% 1-RM 1-RM strength in six different exercises (knee extension, knee flexion, seated bench press, seated row, leg press, biceps curl), performed bilaterally in a weightlifting machine Upper and lower extremities |
Strength: skeletal muscle strength (maximal voluntary muscle strength for knee extension and flexion) Body composition: Total body DEXA |
Significant increase in knee extension with the intervention (d = 0.62) Knee flexion strength showed no effect with the intervention Intervention induced greater increases in total (d = 0.20) and regional (d = 0.19) FFM but no changes in fat mass |
| Cadore 2014 [13] | n = 24 from Europe Age, mean ± SD: 91.9 ± 4.1 70 % women | Institutionalized | Fried’s criteria [2] | Multi-component PRT 12 weeks 2/week 40 min/session 8-10 repetitions 40-60% 1-RM Two exercises for the leg extensor muscles (bilateral leg extension and bilateral knee extension muscles) and one exercise for upper limbs (seated bench press), performed on a resistance variable exercise machine Upper and lower extremities |
Falls: Incidence Mobility: 5 meter walking tests at their habitual speed; TUG; chair rising ability (the most rises in 30 sec) Balance: FICSIT-4 Functional disability: ADLs using BI Strength: Isometric upper and lower limb muscle strength Body composition: fat muscle infiltration |
Exercise training significantly reduced the incidence of falls (d = 2.71) Walking ability did not change with the intervention Exercise training significantly improved the time spent on the TUG (d = 0.42) Significant change in the chair-rising ability test in the intervention group (d = 0.89) Exercise training improved balance (d = 0.72) Exercise training improved functional ability (d = 1.17) Significant increase in knee extension with the intervention (d = 1.74) Upper body muscle strength did not significantly change with the intervention Intervention induced a decrease in fat muscle infiltration (Quadriceps femoris, d = 0.20; and knee flexor, d = 0.10) |
| Faber 2006 [32] | n = 238 from Europe Age, mean ± SD: 84.9 ± 6.0 79 % women | Institutionalized | Frailty indicators adapted from Fried’s criteria [2] | Multi-component functional walking and in balance exercises 20 weeks 1/week for 4 weeks 2/week for 16 weeks 90 min/session Exercise without machines focused on balance, mobility, and transfer training. They included standing up from a chair, reaching and stepping forward and sideward, heel and toe stands, walking and turning, stepping on and over an obstacle, staircase walking, tandem foot standing, and single-limb standing Lower extremities Tailored to the needs of each participant |
Falls: incidence Mobility: POMA; walking tests: 6 meters as fast as possible; TUG; chair rising ability (the time needed to stand up and sit down 5 consecutive times as fast as possible) Balance: POMA; FICSIT-4 Functional disability: ADL and instrumental ADL using GARS |
Exercise training significantly reduced the incidence of falls in the pre-frail elderly sample. In the frail subgroup, the risk of becoming a faller increased with the intervention Positive effect of the intervention on mobility in the pre-frail subgroup. In the frail subgroup, mobility worsened after the intervention Small, but significant, positive intervention effect in POMA score in the exercise group, compared with the control group Exercise training showed no effect on functional ability |
| Fairhall 2014 [33] | n = 241 from Australia/Oceania Age, mean ± SD: 83.3 ± 5.9 68 % women | Community dwelling | Fried’s criteria [2] | Multi-component exercise intervention: Home program of balance and lower limb training based on the WEBB program 12 months 3-5/week 20-30 min/session Exercises without machines Lower extremities Tailored to the needs of each participant |
Falls: incidence; risk of falls (Physiological Profile Assessment [PPA]; short physical performance battery [SPPB]); 4-m walking tests Strength: Lower body strength (knee-extension strength as a component of the PPA) |
Exercise training did not significantly reduce the incidence of falls Exercise training found a better postural sway (d = 0.09) Significant increase in leg muscle extension with the intervention (d = 0.03) Significant improvements in mobility (SPPB score, d = 0.40; and gait speed, d = 0.20) |
| Giné-Garriga 2010 [34] | n = 51 from Europe Age, mean ± SD: 84.0 ± 2.9 61 % women | Community dwelling | Two tests of physical abilities [51, 52] and according to two questions from the Center for Epidemiological Studies depression scale [2] | Multi-component functional based circuit training 12 weeks 2/week 45 min/session 1-2 sets 6-8 repetitions 1 day of balance-based activities and 1 day of lower-body strength-based exercises, combined with function-focused activities. Exercises without machines Lower extremity exercises included activities such as rising from a chair, stair climbing, knee bends, floor transfer, lunges, leg squats, leg extension, leg flexion, calf raises, and abdominal curls using ankle weights |
Mobility: walking tests: 8 meters at their habitual speed and as fast as comfortably possible; MTUG (modified TUG test) Functional disability: ADL using BI Strength: lower body strength (knee-extension and flexion strength) |
Walking ability improved with the intervention (Balance measures: semitandem d = 4.65, tandem d = 6.62, and single leg d = 7.78; Gait speed measures: normal d = 3.50 and fast d = 3.50) Exercise training significantly improved the time spent on the MTUG (assessment questionnaire d = 8.24, and total time d = 4.61) Exercise training improved functional ability (BI score d = 1.08) Significant increase in leg muscle extension with the intervention d = 3.50) |
| Giné-Garriga 2013 [35] | n = 51 from Europe Age, mean ± SD: 84.0 ± 2.9 61 % women | Community dwelling | Two tests of physical abilities [51] and according to two questions from the Center for Epidemiological Studies depression scale [2] | Multi-component functionally based circuit training 12 weeks 2/week 45 min/session 1-2 sets 6-8 repetitions 1 day of balance-based activities and 1 day of lower-body strength-based exercises, combined with function-focused activities. Exercises without machines Lower extremity exercises included activities, such as rising from a chair, stair climbing, knee bends, floor transfer, lunges, leg squat, leg extension, leg flexion, calf raise, and abdominal curl using ankle weights |
Falls: fear of falling (Activities-specific Balance Confidence [ABC] scale) | Exercise training improved the fear of falling (d = 1.10) |
| Kim 2015 [37] | N = 131 from Asia Age, mean ± SD: 80.7 ± 2.8 100 % women | Community dwelling | Fried’s criteria [2] | Physical comprehensive training 12 weeks 2/week 60 min/session 30 minutes of strengthening exercises plus 20 minutes of balance and gait training Strength exercises performed in progressive sequence from the seated to standing positions, and progressive resistance was applied through Thera-bands, with increasing repetition with each exercise Lower extremities consisted of leg extensions, hip flexions, and more. Upper body exercises included double-arm pull downs, bicep curls, and others |
Mobility: walking speed; TUG Strength: Grip strength and isometric knee extension strength Body composition: Total body DEXA Frailty status |
Walking speed did not change with the intervention Exercise training improved the time spent on the TUG (d = 0.64) No increase in knee extension with the intervention Upper body muscle strength did not significantly change with the intervention No effect on body composition of the intervention Exercise training and exercise training plus nutrition supplementation significantly improved frailty status |
| Latham 2003 [36] | n = 243 from Australia/Oceania Age, mean ± SD: 79.1 ± 6.9 53 % women | Teaching hospitals | Winograd’s frailty scale [53] | Home-based resistance training 20 weeks 3/week Initial goal: 3 sets 8 repetitions 30-40% 1RM for 2 weeks Final goal: 3 sets 8 repetitions 60-80% 1RM Accomplished goal: 3 sets 8 repetitions 51% 1RM ±13% Adjustable ankle cuff weights Lower extremities |
Falls: incidence; fear of falling Mobility: 4 meter walking tests; TUG Balance: BBS Functional disability: ADL (BI) and participation in higher non-ADL levels of activity (Adelaide Activity Profiles) Strength: maximal isometric knee extensor strength |
Exercise training did not significantly reduce the incidence of falls Walking ability did not change with the intervention Exercise training did not change TUG measurements Balance was not affected by the intervention No intervention effect on ADL with exercise training No effect on leg muscle extension with the intervention |
| Lustosa 2011 [31] | n = 48 from Brazil Age, mean ± SD: 72.0 ± 4.0 100 % women | Community dwelling | Fried’s criteria [2] | Body weight resistance training 10 weeks 3/week 60 min/session 3 sets 8 repetitions 70% 1RM Ankle weights with loads ranging from 0.5 to 3 kg Lower extremities |
Mobility: 10 meter walking tests at their habitual speed; TUG Strength: Muscle strength of knee extensor |
Walking ability improved with the intervention (d = 0.69) Exercise training significantly improved the time spent on the TUG (d = 0.17) Significant increase in leg muscle extension with the intervention (d = 0.05) |
d = Cohen’s d (effect size). A value of 0.2 indicates a small effect, 0.5 a medium effect and 0.8 a large effect [25]. PRT progressive resistance exercise training, 1-RM one-repetition maximum, WEBB weight-bearing for better balance program, DEXA body dual energy x-ray absorptiometry FFM fat-free mass, FICSIT-4 frailty and injuries: cooperative studies of intervention techniques–4 static balance tests, BI Barthel index, ADL activities of daily living, POMA performance oriented mobility assessment, TUG time up-and-go test, GARS Groningen activity restriction scale, PPA physiological profile assessment, SPPB short physical performance battery, MTUG modified TUG test, ABC activities-specific balance confidence scale, BBS Berg balance scale, FFM fat-free mass