A flow resistive inspiratory muscle training mask worn during high-intensity interval training does not improve 5 km running time-trial performance
Question
Does wearing a flow-resistive breathing mask during HIIT improve 5 km running time-trial performance, respiratory muscle strength, and diaphragm thickness compared with pressure-threshold IMT or HIIT alone?
Summary
Wearing a flow-resistive mask during 6 weeks of treadmill HIIT did not improve 5 km performance more than HIIT alone. Separate pressure-threshold inspiratory muscle training did produce greater improvements.
Methodology
- Healthy, non-smoking recreationally trained runners.
- 23 participants.
- treadmill running.
- Work intervals: 2 min.
- Recovery: 2 min static rest.
- Intensity: speed equivalent to 95% VO2peak.
- 24-40 min interval block plus testing/session setup.
- 3 sessions/week.
- 6 weeks.
- randomized three-group training intervention
- 5 km time trial, Inspiratory strength, Diaphragm thickness, and Pulmonary and perceptual responses were tracked.
Outcomes
5 km time
All groups improved 5 km time, but IMT improved more than mask and HIIT-only.
MASK 3.13 +/- 1.7%, p=0.034; IMT 5.7 +/- 1.5%, p=0.007; CON 2.64 +/- 1.0%, p=0.043; group x time p=0.015
Mask benefit
The flow-resistive mask did not add benefit beyond HIIT alone.
MASK and CON performance changes were similar, p>0.05
PImax and Tdi
Pressure-threshold IMT improved inspiratory strength and diaphragm thickness; mask and control did not.
IMT PImax +32 +/- 16%, p=0.008; Tdi +9.5 +/- 3.4%, p=0.032
Insights
- HIIT itself improved 5 km time, but the mask did not provide extra ergogenic value.
- Dedicated pressure-threshold IMT was more effective than wearing a mask during intervals.
- Consumer breathing-mask claims should be treated cautiously.
Limitations
- Small sample.
- No placebo/sham IMT group.
- Mask resistance was not individualized to PImax.
- Actual inspiratory load and work of breathing during masked exercise were not quantified.
Safety
- No trial adverse events were explicitly reported; the article noted that other mask work had reported reduced alertness/focus during resistance exercise.