ABSTRACT This study aims to assess the effect of short-time low frequency inspiratory muscle trainer (Threshold IMT) on inspiratory muscle strength and electromyographic activity of the sternocleidomastoid (SCM) muscle in people with chronic obstructive pulmonary disease (COPD). People with COPD participating in a lung rehabilitation program were allocated to a control or inspiratory muscle training (IMT) group. The control group participated in the usual rehabilitation, whereas the other group received IMT (performed with a load of 50% maximal inspiratory pressure (MIP) adjusted weekly). Both interventions lasted for 2 months. Outcomes included electromyographic analysis of the SCM and MIP. In total, ten participants were allocated to each group. The IMT group presented an increase in absolute (p