Table 1 Characteristics of included studies

Allsopp et al. [40]

n = 20 (12 males; 8 females)

age: 60–75 yr

Normoxia + exercise (n = 10)

Hypoxia + exercise (n = 10)

Resistance training

(4 exercises at 70% 1RM with 4 × 10 reps)

8 weeks;

2 days per week;

 ~ 60 min per session

Normobaric hypoxia

14.4%

→Glucose

→Insulin

→HOMA-IR

Allsopp et al. [41]

n = 20 (12 males; 8 females)

age: 60–75 yr

Normoxia + exercise (n = 10)

Hypoxia + exercise (n = 10)

Resistance training

(4 exercises at 70% 1RM with 4 × 10 reps)

8 weeks;

2 days per week;

 ~ 60 min per session

Normobaric hypoxia

14.4%

→Lean mass

→Fat mass

→Glucose

→ CHO

→Systolic BP

Camacho-Cardenosa et al. [44]

n = 19 (8 males; 11 females)

age: 65–75 yr

Normoxia + exercise (n = 10)

Hypoxia + exercise (n = 9)

WBV training (12.6 Hz, 4 mm) (4 sets × 30 s, 60-s rest)

18 weeks;

2 days per week;

16 min per session

Normobaric hypoxia

16.1%

→Leg lean mass

→Functional mobility (TUGT)

Camacho-Cardenosa et al. [35]

n = 10

age: ≥ 75 yr

Control, no intervention (n = 5)

Hypoxia (n = 5)

Passive hypoxic exposure

18 weeks;

2 days per week;

16 min per session

Normobaric hypoxia

16.1%

→Body fat mass

→Trunk fat mass

→Femoral BMD

→Trochanter BMD

↑Whole body BMD

Camacho-Cardenosa et al. [43]

n = 31 (11 males, 20 females)

age: ≥ 65–75 yr

Control, no intervention (n = 10)

Normoxia + exercise (n = 11)

Hypoxia + exercise (n = 10)

WBV training (12.6 Hz, 4 mm) (4 sets × 30 s, 60-s rest)

18 weeks;

2 days per week;

16 min per session

Normobaric hypoxia

16.1%

→Body lean mass

→Maximal strength

→Endurance strength

Camacho-Cardenosa et al. [40]

n = 30 (10 males, 20 females)

age: ≥ 65–75 yr

Control, no intervention (n = 10)

Normoxia + exercise (n = 10)

Hypoxia + exercise (n = 10)

WBV training (12.6 Hz, 4 mm) (4 sets × 30 s, 60-s rest)

18 weeks;

2 days per week;

16 min per session

Normobaric hypoxia

16.1%

→Whole body BMD

→Femoral BMD

→Trochanter BMD

Chacaroun et al.[37]

n = 23 (19 males; 4 females)

age: 54 ± 11 yr

Normoxia + exercise (n = 11)

Hypoxia + exercise (n = 12)

Submaximal constant-load exercise in cycle ergometer (75% HR_max)

8 weeks;

3 days per week;

45 min per session

Normobaric hypoxia 13%

→Glucose

→Insulin

→HOMA2-IR

→CHO

→Triglycerides

→HDL

→Lean mass

→Fat mass

→Systolic BP

Chacaroun et al. [36]

n = 35 (24 males, 11 females)

age: 54 ± 9.3 yr

Normoxia, sham condition (n = 11)

Sustained hypoxia (n = 13)

Intermittent hypoxia (n = 12)

Passive hypoxic exposure

8 weeks;

3 days per week;

Sustained hypoxia: 60 min per session

Intermittent hypoxia: 7 cycles (5 min hypoxia + 3 min normoxia) per session

Normobaric hypoxia

FiO2 based on SpO₂ = 75%

→Systolic BP

↓Diastolic BP

→Vascular function (PWV)

→HOMA-IR

→Glucose

→Lipid profile

→CRP

Chobanyan-Jürgens et al. [46]

n = 29 (15 males, 14 females)

age: 55–75 yr

Normoxia + exercise (n = 15)

Hypoxia + exercise (n = 14)

Submaximal bicycle exercise at 60–70% VO₂max

8 weeks;

3 days per week;

30–40 min per session

Normobaric hypoxia

15%

→Insulin sensivity index

→HOMA-IR

→Waist circumference

→%Fat mass

→CHO

→GLUT4

Hein et al. [45]

n = 29 (15 males, 14 females)

age: 55–75 yr

Normoxia + exercise (n = 15)

Hypoxia + exercise (n = 14)

Submaximal bicycle exercise at 60–70% VO₂max

8 weeks;

3 days per week;

30–40 min per session

Normobaric hypoxia

15%

→Body fat mass

→VO₂max

→Rest BP

→Exercise BP

Park et al. [47]

n = 24 (men)

age: 65–70 yr

Normoxia + exercise (n = 12)

Hypoxia + exercise (n = 12)

Aerobic exercise (60–70% HR_max) on treadmill (30 min) and bicycle (30 min) + elastic resistance training (6 exercises, 3 × 10–15 reps; RPE: 6–7 out of 10; 30–45 min)

12 weeks;

3 days per week;

90–120 min per session

Normobaric hypoxia

14.5%

↑Fat-free mass

↓Body fat mass

↑Physical fitness

↑FVC

↑FEV₁

↑MVV

↑HRV (high frequency)

Schega et al.[39]

n = 36 (19 males, 17 females)

age: 60–75 yr

Normoxia + exercise (n = 18)

Hypoxia + exercise (n = 18)

Passive hypoxia exposure (90 min) + aerobic exercise on bicycle (30 min, 70–75% HR_max)

4 weeks;

3 days per week;

120 min per session

Normobaric hypoxia

FiO₂ based on SpO₂ = 80%

→BDNF

→VO₂max

→Cognitive function (Stroop test)

↑Hb; Hct

↑Red-blood cells

Schega et al.[38]

n = 34 (8 males; 16 females)

age: 60–70 yr

Normoxia + exercise (n = 17)

Hypoxia + exercise (n = 17)

Passive hypoxic exposure (60 min) + full-body strength-endurance (30 min, 5 exercises at 50% 1RM with 2 × 25 reps)

6 weeks;

3 days per week;

90 min per session

Normobaric hypoxia

FiO₂ based on SpO₂ = 80%

↑Attention (d2 test)

↑Sleep quality (PSQI test)

→Speed of cognitive performance (ZVT test)

→Quality of life (physical and mental component)

→Strength-endurance capacity

Timon et al. [32]

n = 38 (15 males; 23 females)

age: 65–75 yr

Control, no intervention (n = 19)

Hypoxia (n = 19)

Passive hypoxic exposure

24 weeks;

3 days per week;

45 min per session

Normobaric hypoxia

16.1%

→Lean mass

↓Body fat mass

→Whole body BMD

→Whole body BMC

→Systolic BP

→Glucose

→ CHO

→Triglycerides

CRP

↑PINP

b-CTX

→Interleukin 8

→Interleukin 10

Timon et al. [33]

n = 54 (22 males; 32 females)

age: 65–75 yr

Control, no intervention (n = 19)

Normoxia + exercise (n = 18)

Hypoxia + exercise (n = 17)

Resistance training (9 exercises with elastic bands and kettlebells; 3 sets × 12–15 reps)

24 weeks;

3 days per week;

45 min per session

Normobaric hypoxia

16.1%

→Lean mass

→Fat mass

→Functional fitness (SFT)

→Balance

→Fear of falling

Timon et al. [34]

n = 54 (22 males; 32 females)

age: 65–75 yr

Control, no intervention (n = 19)

Normoxia + exercise (n = 18)

Hypoxia + exercise (n = 17)

Resistance training (9 exercises with elastic bands and kettlebells; 3 sets × 12–15 reps)

24 weeks;

3 days per week;

45 min per session

Normobaric hypoxia

16.1%

→CRP

→Interleukin 6

→Interleukin 8

→Interleukin 10

→VCAM1

Torpel et al.[29]

n = 36 (18 males; 18 females)

age: 60–75 yr

Normoxia + exercise (n = 17)

Hypoxia + exercise (n = 19)

Resistance training (circuit with 8 machine-based resistance exercises at 25–40% 1RM; 3 × 15 reps); RPE: 7 out of 10

5 weeks;

4 days per week;

 ~ 60 min per session

Normobaric hypoxia

FiO₂ based on SpO₂ ranging 80–85%

→Fat mass

→Fat-free mass

→VO₂max

→ Muscular strength

→BP

→Hb

→Erythropoietin

→Blood volume