Table 3 PICO table (Its place within the text is in the “Study design” section)

(Nagy et al., 2022) [13]

Influence of manual diaphragm release technique combined with inspiratory muscle training on selected persistent symptoms in men with post-covid-19 syndrome: A randomized controlled trial

Randomized controlled trial.

N = 52.

Participant age: 30–45 years.

Intervention time: 6 weeks

I.G: diaphragm release plus Inspiratory muscle training via POWERbreath.

C.G: Inspiratory muscle training

• PImax.

• SBP.

• DBP.

• 6-MWTD.

• Fatigue: FSS.

• Dyspnea: MMRC.

• Serum lactate level.

The results showed a statistically significant improvement for all secondary outcomes in both groups. However, in the main outcome, maximum static inspiratory pressure, it increased significantly by 48.17% (p < 0.001) in the intervention group with no significant change in the control group.

(Rutkowski et al., 2023) [14]

Inpatient post-COVID-19 rehabilitation program featuring virtual reality—Preliminary results of randomized controlled trial

Preliminary results of randomized controlled trial

N = 32.

Participant age: 40–80 years.

Intervention time: 3 weeks

I.G: pulmonary rehabilitation through virtual reality.

C.G: traditional pulmonary rehabilitation program.

• 6-MWTD.

• FEV₁.

• FVC and FEV₁.

• TLC.

• Perceived dyspnea: the Borg scales.

• Stress level: The Perceived Stress Scale (PSS-10).

Regarding exercise capacity, both groups improved, without being significant. In dyspnea, both groups obtained a significant improvement, the control group (p < 0.004) and the intervention group (p < 0.033).

(Alshaimaa et al., 2023) [15]

Impact Of Active Cycle Of Breathing Technique

On Selected Pulmonary Outcomes In Post-COVID Syndrome Patients

Randomized controlled trial.

N = 60.

Participant age: 40–50 years.

Intervention time: 12 weeks

A.G: aerobic exercise, muscle

strengthening, and respiratory exercise.

B.G: an active cycle of breathing technique in

addition to what A.G received.

• Evaluating arterial blood gases.

• 6-MWTD.

• Fatigue: FAS.

In the 6-MWTD variable, a significant improvement was identified in both groups (p > 0.001). Both groups also obtained a reduction in fatigue, the difference between both groups being statistically significant (p < 0.001).

(Jimeno et al., 2022) [16]

Rehabilitation for post-COVID‐19 condition through a supervised exercise intervention: A randomized controlled trial

Randomized controlled trial.

N = 39.

Participant age: It does not indicate, > 18 years. Average age: 45.2

Intervention time: 8 weeks

I.G: tailored and supervised multicomponent exercise programme.

C.G: WHO guidelines.

• Severity of symptoms

And quality of life: SF-12.

• Physical fitness: using a cycle exercise test.

• Cardiopulmonary function: resting electrocardiogram and echocardiogram. In addition, FVC, FEV1, and

MMV.

• Dyspnea: MMRC.

• Fatigue: FSS and CFS.

In comparison with the control group, supervised, controlled, and personalized training at low to moderate intensities has been found to be a more effective and safer intervention. Of the four variables relevant to our study (dyspnea, fatigue, pulmonary function, and quality of life), the latter three experienced significant improvement in the intervention group.

(Jimeno et al., 2023) [17]

Effects of a concurrent training, respiratory muscle exercise, and self-management recommendations on recovery from post-COVID-19 conditions: the RECOVE trial

Randomized controlled trial.

N = 80.

Participant age: It does not indicate, > 18 years.

Intervention time: 8 weeks

G.1 (CT): multicomponent exercise programme.

G.2 (RM): inspiratory muscle training programme.

G.3 (CTRM): multicomponent exercise programme plus inspiratory muscle training programme.

G.4 (CON): control group, informed to follow the WHO guideline.

• Cardiorespiratory fitness: submaximal multistage and individualized cardiopulmonary exercise test on a cycle ergometer.

• Muscle strength: progressive loading test up to the 1RM.

• Severity of symptoms: the 12-item Short Form Survey (SF-12).

• Dyspnea: MMRC.

• Fatigue: FSS and CFS.

G.1 and G.3 obtained better results compared to the other two groups (p < 0.05).