A flow resistive inspiratory muscle training mask worn during high-intensity interval training does not improve 5 km running time-trial performance.

Purpose: There is little evidence of the ergogenic effect of flow-resistive masks worn during exercise. We compared a flow-resistive face mask (MASK) worn during high-intensity interval training (HIIT) against pressure threshold loading inspiratory muscle training (IMT).

Methods: 23 participants (13 males) completed a 5 km time trial and six weeks of HIIT (3 sessions weekly).