UNASSIGNED: A novel commercial training mask purportedly allows for combined respiratory muscle training and altitude exposure during exercise. We examined the mask's ability to deliver on this claim. Ten males completed three bouts of treadmill exercise at a matched workload(60%VO2peak) in a controlled laboratory environment. During exercise the mask was worn in two manufacturer-defined settings [9000ft(9k) and 15,000ft(15k)] and a Sham configuration(   3500ft). Ventilation(VE), tidal volume(VT), respiratory rate(RR), expired @entity26 (FEO2) and @entity544 (FECO2), peripheral @entity26 saturation(SPO2), heart rate(HR), and RPE were measured each minute during exercise and subjects completed the Beck Anxiety Inventory(BAI) immediately following. The mask caused a reduction in VE of    20L/min in both the 9k and 15k configurations(p<0.001). This was due to a reduction in RR of    10 bpm, but not VT, which was elevated by    250ml(p<0.001). FEO2 was reduced and FECO2 was elevated above Sham in both 9k and 15k(p<0.001). @entity4962 was not different across conditions(p=0.210) butVCO2 trended lower at 9k(p=0.093) and was reduced at 15k(p=0.016). VE/VO2 was 18.3% lower than Sham at 9k and 19.2% lower at 15k. VE/VCO2 was 16.2% lower than Sham at 9k and 18.8% lower at 15k(all p<0.001). HR increased with exercise(p<0.001) but was not different between conditions(p=0.285). SPO2 averaged 94% in Sham, 91% at 9k, and 89% at 15k(p<0.001). RPE and BAI were also higher in 9k and 15k(p<0.010) but there was no difference between mask conditions. The training mask caused inadequate hyperventilation that led to arterial @entity519 and psychological discomfort, but the magnitude of these responses were small and they did not vary across mask configurations.

'Functional' respiratory muscle training during endurance exercise causes modest XXXX but overall is well tolerated.

@entity4962 :: ('CHEBI:30046', 'Chemical') :: ['VO2'] @entity26 :: ('MESH:D010100', 'Chemical') :: ['oxygen'] @entity519 :: ('MESH:D000860', 'Disease') :: ['hypoxemia'] @entity544 :: ('MESH:D002245', 'Chemical') :: ['carbon dioxide']
@entity519 :: (MESH:D000860,Disease) :: ['hypoxemia']
