Inspiratory muscle warm-up attenuates muscle deoxygenation during cycling exercise in women athletes

• Inspiratory muscle warm-up (IMW) has been examined for enhancing exercise tolerance.
• IMW results in a smaller fall in tissue saturation index (TSI) in working muscles.
• IMW might not improve intermittent high-intensity cycling sprint (IHIS) performance.
• Studies should examine the protection against the fall in TSI during prolonged IHIS.

This study examines the effects of inspiratory muscle warm-up (IMW) on performance and muscle oxygenation during cycling exercise. In a randomized crossover study of 10 female soccer players, the IMW, placebo (IMWP) and control (CON) trials were conducted before two 6-min submaximal cycling exercises (100 and 150 W) followed by intermittent high-intensity sprint (IHIS, 6 × 10 s with 60 s recovery). The reduction in tissue saturation index (TSI) in legs in the IMW were significantly less than those in IMWP and CON (P < 0.01) during submaximal cycling exercises. The average reduction in TSI during the IHIS test with IMW was significantly less than those in the IMWP and CON (P = 0.023). Nevertheless, the IHIS performance with IMW did not differ from that in other trials. In conclusion, the leg TSI during continuous submaximal cycling exercise followed by intermittent sprinting was likely improved by specific IMW (40% maximal inspiratory mouth pressure), which did not enhance IHIS performance.