Table 4.
Description of the interventions and the results.
| First Author, Year | Type of Training | Starting Intensity | Progression of Training Intensity | Number of Sessions per Week | Number of Weeks | Duration of Exercise | Supervision | Control/Placebo | Specific Test | Main Results of the Analyzed Variables |
|---|---|---|---|---|---|---|---|---|---|---|
| Romer, 2002 [58] | POWERbreathe (threshold) | 50% MIP | Progressive increase, until they can only do 30 repetitions | 2 sessions daily, 7 days per week | 6 weeks | 30 inspirations | Supervised | Placebo: 1 session of 60 inspirations at 15% MIP | RSA | ↑ PIF (≈20%) ↑ MIP (≈33%) ↑ Performance (≈7%) |
| Tong, 2006 [47] | POWERbreathe (threshold) | 40% MIP | No progression | 2 pre-test sessions | Only 1 test | 30 inspirations | Supervised | Placebo: same protocol, but at 15% MIP Control: no intervention |
Yo-Yo intermittent recovery test | ↑ MIP (≈9%) ↑ Vmax (≈5%) ↑ WImax (≈21%) ↑ Popt (≈16%) ↑ MRPD (≈13%) ↓ RPB/4i (≈22%) ↑ Performance (≈19%) |
| Lin, 2007 [46] | POWERbreathe (threshold) | 40% MIP | No progression | 2 pre-test sessions | Only 1 test | 30 inspirations | Supervised | Placebo: same protocol, but at 15% MIP Control: no intervention |
Badminton-footwork test | ↑ P0 (≈8%) ↑ MRPD (≈9%) ↓ RPB/min (≈7%) ↑ Performance (≈7%) |
| Tong, 2008 [38] | POWERbreathe (threshold) | 50% MIP | Increase of 10 or 15 cmH2O when 30 repetitions are performed without stopping | 2 sessions daily, 6 days per week | 6 weeks | 30 inspirations | Supervised | Placebo: same protocol, but at 15% MIP Control: no intervention |
Yo-Yo intermittent recovery test | ↑ P0 (≈32%) ↑ WImax (≈40%) ↑ Popt (≈38%) ↑ MRPD (≈39%) ↓ RPE/4i (≈11%) ↓ RPB/4i (≈12%) ↓ 20 m VE (≈10%) ↓ 20 m VT/ti (≈8%) ↑ Performance (≈16%) |
| Nicks, 2009 [59] | PowerLung (threshold) | 50% MIP | Progressive increase once or twice a week, until they can only do 30 repetitions | 2 sessions daily, 5 days per week | 5 weeks | 30 inspirations | Normally supervised, when not, participants submitted training logs | Control: no intervention | RSA | ↑ MIP (≈20%) ↑ Performance (≈17%) |
| Tong, 2010 [50] | POWERbreathe (threshold) | EIMT = 50% MIP EWU = 40% MIP |
Increase of 10 or 15 cm H2O when 30 repetitions are performed without stopping | EIMT = 2 sessions daily, 6 days per week EWU = 2 pre-test sessions |
EIMT = 4 weeks EWU = 6 weeks |
30 inspirations | Not reported | Control: no intervention | Yo-Yo intermittent recovery test | ↑ P0 (≈20%) ↓ RPE (≈8%) ↓ RPB (≈16%) ↓ 20 m VE (≈10%) ↓ 20 m VE/VO2 (≈8%) ↓ 20 m VT/Ti (≈10%) ↓ 10 s VE (≈10%) ↓ 10 s VE/VO2 (≈5%) ↑ Performance1 (≈31%) ↑ Performance2 (200 m, ≈ 25%; 600 m, ≈ 53%; 800 m, ≈ 36%) |
| Guy, 2014 [32] | POWERbreathe (threshold) | 55% MIP | No progression | 2 sessions daily, 2 days per week | 6 weeks | 30 inspirations | Not reported | Placebo: same protocol, but at 15% MIP Control: no intervention |
SSFT | ↑ MIP (≈13%) ↓ Blood lactate (≈32%) |
| Archiza, 2017 [48] | POWERbreathe (threshold) | 50% MIP | Progressive increase every week | 2 sessions daily, 5 days per week | 6 weeks | 30 inspirations | Supervised | Placebo: same protocol, but at 15% MIP | RSA | ↑ MIP (≈22%) ↓ RSABEST (≈4%) ↓ RSAMEAN (≈6%) ↓ RSADEC (≈30%) |
| Nunes Júnior, 2018 [60] | Breather Plus IMT Power (threshold) | 80% MIP | Progressive increase from the fourth training session | 3 sessions per week | 12 weeks | 30 inspirations | Supervised | Control: same protocol but without resistance | Yo-Yo intermittent recovery test | ↑ MVV (22%) ↑ MIP (≈29%) ↑ MEP (≈32%) ↑ Performance (≈14%) |
| Najafi, 2019 [37] | POWERbreathe (threshold) | E1 = 55% MIP E2 = 45% MIP |
Progressive increase once a week | 2 sessions daily, 5 days per week | 8 weeks | E1 = 25–35 inspirations E2 = 45–55 inspirations |
Supervised | Placebo: 30 inspirations at 15% MIP | Yo-Yo intermittent recovery test | ↑ MIP (E1: 27.2%; E2: 30.6%) ↓ RPE (E1: 26.9%; E2: 28.9%) ↓ RPB (E1: 62.1%; E2: 56.3%) ↓ Lactate (E1: 29.4%; E2: 27.5) ↓ Fatigue index (E1: 34.4%; E2: 40.6%) ↑ Performance (E1: 8.9%; E2: 8.1%) |
* MIP = maximal inspiratory pressure, RSA = repeated sprint ability, PIF = peak inspiratory flow, Vmax = maximal inspiratory flow, WImax = maximal inspiratory muscle power, Popt = optimal pressure, MRPD = maximum rate of pressure development, RPB = rating of perceived dyspnea, P0 = maximal inspiratory pressure at zero flow, RPE = rating of perceived exertion, 20 m = sprint of 20 m, VE = minute ventilation, VT = tidal volume, Ti = inspiratory time, EIMT = chronic inspiratory muscle training, EWU = acute inspiratory muscle training (warm-up), RSABEST = RSA best performance time, RSAMEAN = RSA mean performance time, RSADEC = RSA performance decrement, MVV = maximum voluntary ventilation, MEP = maximal expiratory pressure, SSFT = soccer-specific fitness test protocol, E1 = IMT group number one, E2 = IMT group number two, ↑ = significant increase over control group (p < 0.05), ↓ = significant decrease over control group.