title: Resistive loaded breathing has a functional impact on maximal voluntary contractions in humans.
abstract: Resistive loaded breathing (RL) can modulate the electromyogram pattern during an isometric arm flexion or leg extension at 70-80% of voluntary maximal contraction (MVC). This study tested the hypothesis that an interaction between the respiratory muscle afferent activity during RL and the descending motor drive may also have a functional impact on voluntary maximal performance. Therefore, muscle contractions (100% of MVC) were performed with four muscles during phase specific expiratory (ERL) or inspiratory (IRL) resistive loading and force or the steadiness of the force produced were compared with non-RL controls. Both IRL and ERL reduced MVC in leg muscles, especially biceps femoris. IRL caused a reduction in steadiness in the same muscle. These results suggest a hitherto understated impact of RL on functional performance in leg muscles.
authors.affiliation: Exercise Neuroscience Research Group, School of Applied Science, South Bank University, London SE1 0AA, UK. turnerdl@sbu.ac.uk
authors.forename: Duncan
authors.initials: D
authors.lastname: Turner
authors.forename: Stephen
authors.initials: S
authors.lastname: Jackson
mesh_terms: D000328:Adult; D000403:Airway Resistance / Q000502:physiology*; D004576:Electromyography; D006801:Humans; D001239:Inhalation; D007866:Leg; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D012016:Reference Values; D012143:Respiratory Physiological Phenomena; D014939:Work of Breathing