Abstract
We investigated how inspiratory muscle training impacted respiratory and locomotor
muscle deoxygenation during submaximal exercise with resistive inspiratory loading.
16 male cyclists completed 6 weeks of either true (n=8) or sham (n=8) inspiratory
muscle training. Pre- and post-training, subjects completed 3, 6-min experimental
trials performed at ~80% ˙VO2peak with interventions of either moderate inspiratory loading, heavy inspiratory loading,
or maximal exercise imposed in the final 3 min. Locomotor and respiratory muscle oxy-,
deoxy-, and total-haemoglobin and myoglobin concentration was continuously monitored
using near-infrared spectroscopy. Locomotor muscle deoxygenation changes from 80%
˙VO2peak to heavy inspiratory loading were significantly reduced pre- to post-training from
4.3±5.6 µM to 2.7±4.7 µM. Respiratory muscle deoxygenation was also significantly
reduced during the heavy inspiratory loading trial (4.6±3.5 µM to 1.9±1.5 µM) post-training.
There was no significant difference in oxy-, deoxy-, or total-haemoglobin and myoglobin
during any of the other loading trials, from pre- to post-training, in either group.
After inspiratory muscle training, highly-trained cyclists exhibited decreased locomotor
and respiratory muscle deoxygenation during exercise with heavy inspiratory loading.
These data suggest that inspiratory muscle training reduces oxygen extraction by the
active respiratory and limb muscles, which may reflect changes in respiratory and
locomotor muscle oxygen delivery.
Key words
respiratory muscles - muscle oxygenation - near-infrared spectroscopy - respiratory
muscle training
