Maximal inspiratory pressure is influenced by intensity of the warm-up protocol

• We measured the acute effect of different inspiratory muscle (IM) warm-up intensities on Maximal Inspiratory Pressure (MIP).
• Previous studies have shown that IM warm-up may help athletic performance.
• IM warm-up with 40% (2 × 30 inspirations) and 60% (2 × 12 inspirations) of MIP significantly increased MIP values.
• Future research should measure the effect of higher intensity of IM warm-up on athletic performance.

The aim of the study was to compare the effect of inspiratory muscle warm-up protocols with different intensities and breathing repetitions on maximal inspiratory pressure (MIP). Ten healthy and recreationally active men (183.3 ± 5.5 cm, 83.7 ± 7.8 kg, 26.4 ± 4.1 years) completed four different inspiratory muscle (IM) warm-up protocols (2 × 30 inspirations at 40% MIP, 2 × 12 inspirations at 60% MIP, 2 × 6 inspirations at 80% MIP, 2 × 30 inspirations at 15% MIP) on separate, randomly assigned visits. Pre-post values of MIP using MicroRPM (Micro Medical, Kent, UK) showed a significant increase in the mean values after the IM warm-up (POWERbreathe® K1, Warwickshire, UK) with 40% MIP and 60% MIP warm-up protocols, when MIP increased by 7 cm H2O (95% CI: 0.10…13.89) (p = 0.047) and by 6.4 cm H2O (95% CI: 2.98…13.83) (p = 0.027), respectively. In conclusion, a higher intensity inspiratory muscle warm-up protocol (2 × 12 breaths at 60% of MIP) can increase IM strength.