Effects of Inspiratory Muscle Warm-up on Respiratory Variables, Physiological Indices, and 400-meter Performance in Elite Male Runners - Randomized Crossover Trial

Inspiratory Muscle Warm-up Protocols In addition to athletic warm-up an athletic warm-up protocol, participants performed inspiratory muscle warm-up (IMW) using the POWERbreathe® Plus Blue Medium Resistance (POWERbreathe International Ltd., Warwickshire, England UK). In the IW60 arm, inspiratory muscle warm-up was performed at 60% of maximal inspiratory pressure (MIP). Each protocol consisted of two sets of 30 repetitions (Marostegan et al., 2022; Demirkan et al., 2025).

Inspiratory Muscle Warm-up Protocols In addition to athletic warm-up an athletic warm-up protocol, participants performed inspiratory muscle warm-up (IMW) using the POWERbreathe® Plus Blue Medium Resistance (POWERbreathe International Ltd., Warwickshire, England UK). In the IW40 arm, inspiratory muscle warm-up was performed at 40% of maximal inspiratory pressure (MIP). Each protocol consisted of two sets of 30 repetitions (Marostegan et al., 2022; Demirkan et al., 2025).

In addition to athletic warm-up an athletic warm-up protocol, participants performed inspiratory muscle warm-up (IMW) using the POWERbreathe® Plus Blue Medium Resistance (POWERbreathe International Ltd., Warwickshire, England UK). In the sham arm, inspiratory muscle warm-up was performed at 15% of maximal inspiratory pressure (MIP). Each protocol consisted of two sets of 30 repetitions (Marostegan et al., 2022; Demirkan et al., 2025).