Table 1.
Summary of studies examining the impact of inspiratory muscle training on exercise performance
| Study | Population | Protocol | Outcome |
|---|---|---|---|
| Chatham et al. [16] | 22 healthy subjects (10 male, 12 female) | 8-week flow-resistive IMT; 3 times weekly using TIRE regimen (progressive work: rest ratio at 80% of sustained maximal inspiratory pressure, up to 36 breaths per session) | PImax increased by 42 cm H2O; 9.8% improvement in shuttle run performance |
| Volianitis et al. [115] | 14 female competitive rowers | 11-week pressure-threshold IMT; 30 breaths at 50% PImax twice daily | PImax increased by 44 ± 25 cm H2O; distance covered in 6-min all-out effort increased by 3.5 ± 1.2%, 5000 m time trial improved by 36 ± 9 s |
| Romer et al. [92] | 16 male trained cyclists | 6-week pressure-threshold IMT; 30 breaths at 50% PImax twice daily | PImax increased by 28 ± 7%; 40-km cycling time trial performance improved by 4.6 ± 1.9%, 20-km time trial improved by 3.8 ± 1.7% |
| Romer et al. [93] | 24 male repetitive sprint athletes | 6-week pressure-threshold IMT; 30 breaths at 50% PImax twice daily | PImax increased by 30.5 ± 2.2%; total recovery time during repetitive sprint test improved by 6.2 ± 1.1% |
| Gething et al. [34] | 15 apparently healthy subjects (10 male, 5 female) | 10-week flow-resistive IMT; 3 times weekly using TIRE regimen (progressive work: rest ratio at 80% of sustained maximal inspiratory pressure, up to 36 breaths per session) | PImax increased by 34%; cycling time to exhaustion at 75% of VO2peak improved by 36% |
| Enright et al. [26] | 20 moderately trained adults (9 male, 11 female) | 8-week flow-resistive IMT; 3 times weekly using TIRE regimen (progressive work: rest ratio at 80% of sustained maximal inspiratory pressure, up to 36 breaths per session) | PImax increased by 41%; Exercise capacity improved by 23% in progressive, incremental test on cycle ergometer (beginning with no resistance, then 8-W increases every minute until volitional exhaustion or reaching 80% of age-predicted maximum heart rate) |
| Kilding et al. [58] | 16 competitive club-level swimmers | 6-week pressure-threshold IMT; 30 breaths at 50% PImax twice daily | PImax increased by 9.1 ± 4.2%; 100-m swim time improved by 1.7 ± 1.4%, 200-m swim time improved by 1.5 ± 1.0% |
| Mickleborough et al. [69] | 24 recreational road runners | 6-week flow-resistive IMT; 3 times weekly using TIRE regimen (progressive work: rest ratio at 80% of sustained maximal inspiratory pressure, up to 36 breaths per session) | PImax increased by 43.9%; Endurance capacity during treadmill run set at 80% VO2max improved by 16.4% |
| Turner et al. [111] | 16 male highly trained cyclists | 6-week pressure-threshold IMT; 30 breaths at 50% PImax twice daily | PImax increased by 22.5 ± 8.7%; Oxygen cost of voluntary hyperpnea decreased by 1.5% at 75% of VO2max and 3.4% at 100% of VO2max |