Table 3 Characteristics of Included Studies Mixed Training as an Exercise Training Mode

1

Bagheri et al. (2020) [56]

20/0

63.8 ± 3.6/65 ± 3.9

HGS < 26–30 kg, GS < 0.8 m/s, BMI at least two standard deviations below the average young population (EWGSOP-2010)

Resistance machine

1.RT: leg extension, leg curl, bench press, lat pulldown, lateral raise, abdominal crunch.

Beginning: 8–16 reps, 40% 1RM; Progressed to: 75% 1RM

3(8)

Non-exercise

SMM; KES

Fixed-speed bike

2.ET

Beginning: 55% maxHR, 15 min;Progressed to: 70% maxHR, 30 min

2

Chen et al. (2017) [42]

5/25

68.5 ± 2.7/68.6 ± 3.1

ASMI by BIA, M:

≤32.5%, F: ≤25.7% (Chung)

Weight machine

1.RT: shoulder presses, bicep curls, triceps curls, bench presses, deadlifts, leg swings, squats, standing rows, unilateral rows, and split front squats

3 sets/8–12 reps;60–70% 1RM

1(8)

Non-exercise;

SMM; HGS, KES

/

2.AT: a combination of dance steps such as stepping on the spot, knee lifts, high knee running, rowing arm swings, arm swings, twist steps, arm raises, squats, V steps, mambo steps, diamond steps, and point step jumps;

/

3

Hassan et al. (2015) [57]

Not identified

85.9 ± 7.5

SMI by BIA, M: < 8.87 kg/m², F: < 6.42 kg/m²

HGS, M: < 30 kg, F: < 20 kg; GS, < 0.8 m/s (EWGSOP2010)

Air-pneumatic equipment

1.RT: elbow and shoulder extension, leg press, knee extension and flexion, hip abduction and adduction, abdominal curl and back extension

2–3 sets/10–15 times;Intensity: Borg RPE 12–14

2(24)

Non-exercise

SMI; HGS; GS

2.Balance exercises: heel and toe raise, varied directional quick stepping, reaching, single leg standing, static balance, heel to toe walking and complex cross over stepping activities.

3 sets/10 reps

→3 sets/15 reps

4

Kim et al. (2012) [58]

0/78

79.0 ± 2.9/78.7 ± 2.8

1) ASMI by BIA < 6.42 kg/m² and KES < 1.01 Nm/kg;

2) ASMI by BIA < 6.42 kg/m²

and GS < 1.22 m/s;

3) BMI < 22.0 kg/m, KES < 1.01 Nm/kg;

4) BMI < 22.0 kg/m² and GS < 1.22 m/s (Kim 2012/2013)

Resistance band or ankle weight

1.RT: (1) Chair exercise: ①Repetitions of toe raises, heel raises, knee lifts, knee extensions, and others were performed while seated on a chair; ②Hip flexions, lateral leg raises, and repetitions of other exercises while standing upright behind the chair and holding the back of the chair for stability. (2) Ankle-weight exercise: seated knee flexion, extension, standing knee flexion extensions

1 set/8 reps; Intensity: Borg RPE 12–14

2(12)

Education (1 month/time, 3 times)

MM, AMM; KES; GS

2.Balance and gait training: raising the toes during the forward swing of the leg, kicking off the floor with the ball of the foot, walking with directional changes, gait pattern variations.

Weights of 0.50, 0.75, 1.00, and 1.50 kg

5

Kim et al. (2013) [59]

0/64

79.6 ± 4.2/80.2 ± 5.6

1) ASMI < 6.42 kg/m² and KES < 1.01 Nm/kg;

2) ASMI < 6.42 kg/m²

and GS < 1.22 m/s;

3) BMI < 22.0 kg/m, KES < 1.01 Nm/kg;

4) BMI < 22.0 kg/m² and GS < 1.22 m/s.

(Kim 2012/2013)

Resistance band and ankle weight

1.RT: focused on hip extensors and adductors, knee flexors and extensors, ankle dorsi, plantar flexors.

1 set/8 reps→ gradually increased to 2 sets/10 reps

2(12)

Non-exercise

MM, ASM; HGS, KES; GS, TUG

/

2.Gait and balance training: toe elevation of the forward leg, heel elevation of the rear limb; one-leg stands, tandem stand, tandem walking

/

6

Kim et al. (2016) [60]

0/69

81.4 ± 4.3/81.1 ± 5.1

SMI by DXA: < 5.67 kg/m²;

HGS < 17.0 kg;

GS < 1.0 m/s

(Kim 2016)

Weight machine; Resistance band; Hydraulic exercise machine

1.RT: (1) Chair exercise: toe raise, heel raises, knee lifts, knee extensions; hip flexions, lateral leg raises, standing upright behind the chair and holding the back;

(2) Resistance band exercise: double-arm pulldowns, bicep curls, leg extensions, hip flexions; (3) Machine: seated row, leg press, abduction, leg extension, abdominal crunch machines

1–3 sets/10 reps

2(12)

Education (2 weeks/time, 6 times)

MM, AMM, ASM; HGS, KES; GS

/

2.AT

1 set/10 reps→3 sets/10 reps

7

Makizako et al. (2020) [33]

21/51

74.1 ± 6.6/75.8 ± 7.3

ASMI by BIA, M: < 7.0 kg/m², F: < 5.7 kg/m² (AWGS)

Resistance band

1.RT: knee extension, hip flexion (knee raises), hip internal rotation, elbow flexion and shoulder abduction, elbow flexion and trunk rotation, hip extension, knee flexion, hip abduction, and squat.

5 resistance levels/10 reps; Intensity: Borg RPE 12–14

12 weeks

Education (60 min, 1 time)

ASMI; HGS; GS, CS, TUG

/

2.Balance and AT: tandem stand, heel-up stand, one-leg stand, weight shifts, and stepping; anterior-posterior or lateral stepping repetitions for 6 min.

/

8

Maruya et al. (2016) [50]

23/29

69.2 ± 5.6/68.5 ± 6.2

SMI by BIA, M: < 7.0 kg/m², F: < 5.7 kg/m² (AWGS)

Weight

1.RT: (1) Squats: a 6-s movement time, and then to slowly return to their standing position; (2) Single-leg standing: a single-leg standing posture for 1 min, using light touch on stable desk or chair; (3) Heel raises

3 sets/6 reps; 3 sets; 3 sets/20 reps

6 months

Non-exercise

SMI; HGS, KES; GS, SPPB

/

2.AT: walking

20–30 min/day

9

Moghadam et al. (2020) [61]

20/0

64.1 ± 3.3/65 ± 3.9

HGS < 26–30 kg, GS < 0.8 m/s, SMI at least two standard deviations below the average young population (EWGSOP-2010)

Resistance machine

1.RT: leg extension, leg curl, bench press, lat pulldown, lateral raise, and abdominal crunch

Beginning: 2 sets/16–18 reps, 40% 1RM; Progressed to: 3 sets/8–10 reps, 75% 1RM

3(8)

Non-exercise

KES

fixed-speed cycle ergometer

2.ET

Beginning: 55% of maxHR, 15 min; Progressed to: 70% maxHR, 30 min

10

Park et al. (2017) [62]

0/50

73.5 ± 7.1/74.7 ± 5.1

ASM/weight <25.1% (Park)

/

1.AT: sideways, backward, and forward walking, slow and fast indoor walking;

W1–12:

13–15 RPE; W13–24:

≤15 RPE

5(24)

Education (2 times)

ASM; HGS; CS, GS

Thera-Band

2.RT: elbow flexion, wrist flexion, shoulder flexion, lateral raise, front raise, chest press, reverse flies, side band, dead lift, squat, leg press, ankle plantar flexion.

W1–12:

8–11 reps/set; W13–24:

12–15 reps/set

3(24)

11

Shahar et al. (2013) [63]

Not identified

69.74 ± 5.46/67.25 ± 5.48

SMI by BIA, M: < 10.75 kg/m², F: < 6.75 kg/m² (NHANES III)

1.AT: walking and jogging on the spot; walking forwards, backwards, sideways; arm movements; raising the head, moving it in circularly; moving the trunk in four directions; and pushing knee forwards and backwards.

/

2(12)

Relaxation (2 weeks/ time, 6 times)

MM; HGS; CS, TUG, 6MWT

Elastic band

2.RT: shoulder abduction; shoulder flexion; triceps extension; overhead press, side lateral extension; a standing double biceps curl; leg extension; foot extension; plantar flexion.

/

3.Balance exercises: stand on their heels; stand on one leg with the other leg on the ground or lifted behind or aside; stand on one leg while lifting up the opposite hand; and to walk foot by foot with fingers touching the foot from the back.

12

Tsekoura et al. (2018) [23]

4/32

74.56 ± 6.04/72.89 ± 8.31

SMI by BIA, M: < 7.23 kg/m², F: < 5.67 kg/m² (EWGSOP-2010)

Weight

1.AT: walking

30–35 min/time

3(12)

Education

SMI; HGS, KES; GS, TUG, CS

2.RT: knee extensor-flexor, hip abductor-extension, ankle plantar flexors- dorsi flexors, wall push up, seated bicep curl, seated triceps extension, seated lateral shoulder raises, seated abdominal crunches

W1–4:

1 set/8 reps; Intensity: Borg RPE 10–11 (Easy)

W5–8:

2 sets/10 reps; Intensity: Borg RPE 10–12 (Easy)

W9–12:

2 sets/12reps; Intensity: Borg RPE 12 (Medium)

2(12)

3.Balance and gait training: walking and turning around, walking- backward tandem-heel-toe- heel to toe-sideways, one leg stand, tandem stance

/

13

Vasconcelos et al. (2016) [64]

0/28

72 ± 4.6/72 ± 3.6

BMI ≥30 kg/m², HGS ≤21 kg (Fried)

/

1. stretching exercise: remained the same, 60 s in each leg for posterior, anterior, lateral, and medial muscles of hips and knees

Using the modified Borg Scale

2(10)

Non-exercise

KES; GS, SPPB

Weight

2.RT: (1) W1–4: a low speed concentric and eccentric movements) → the high-speed (focusing on muscle power); (2) W5–6: perform the concentric movements of exercises “as fast as possible”; (3)W7–10: concentric and eccentric movements in high speeds

W1–2: (1) Knee exercise: 2 sets/12 reps, 50% 1RM; (2) Hip exercises: 2 sets/8 reps; (3) Mini-squats, against the wall: 2 sets/10 reps

W3–4: (1) Knee exercise: 2 sets/12 reps, 75% 1RM; (2) Hip exercises: 2 sets/8 reps, 2 kg; (3) Mini-squats: 2 sets/10 reps

W5–6: (1) Knee exercise: 2 sets/12 reps, 40% 1RM; (2) Hip exercises: 2 sets/8 reps, 2 kg; (3) Mini-squats: 2 sets/10 reps

W7–8: (1) Knee exercise: 2 sets/12 reps, 60% 1RM; (2) Hip exercises: 2 sets/8 reps, 3 kg; (3) Mini-squats: 2 sets/10 reps W9–10: (1) Knee exercise: 3 sets/12 reps, 60% 1RM; (2) Hip exercises: 3 sets/8 reps, 3 kg; (3) Mini-squats: 3sets/10 reps

14

Zhu et al. (2019) [65]

19/58

74.5 ± 7.1/72.2 ± 6.6

SMI by BIA, M: < 7.0 kg/m², F: < 5.7 kg/m² (AWGS)

Thera-Band

1.RT: chest, back, biceps, triceps; knee extension/flexion, heel raises, side leg lifts)

6 sets/6–8 reps; 40% 1RM

2(12)

Non-exercise

ASMI, AMM; HGS; GS, CS

/

2.AT

/